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stdc

Index


--background_C99-- --background_locale-- --background_string-- --background_wchar--
__stdc_assert() __stdc_get_errorptr() __stdc_gmtoffset() __stdc_jmp2exit()
__stdc_program_end() __stdc_program_startup() __stdc_set_errorptr() __stdc_set_exitjmp()
__stdc_strerror() __stdcio_assert() __stdcio_get_environptr() __stdcio_get_envlistptr()
__stdcio_set_environptr() __stdcio_set_envlistptr() __vcformat() _Exit()
abort() abs() asctime() asctime_r()
asprintf() assert() atexit() atof()
atoi() atol() atoll() bsearch()
calloc() clearerr() clock() ctime()
ctime_r() difftime() div() exit()
fclose() feof() ferror() fflush()
fgetc() fgetpos() fgets() fopen()
fprintf() fputc() fputs() fread()
free() freopen() fscanf() fseek()
fsetpos() ftell() fwrite() getc()
getchar() getenv() gets() gmtime()
gmtime_r() imaxabs() imaxdiv() isalnum()
isalpha() isascii() isblank() iscntrl()
isdigit() isgraph() islower() isprint()
ispunct() isspace() isupper() isxdigit()
labs() ldiv() llabs() lldiv()
localeconv() localtime() localtime_r() malloc()
malloc_align() mblen() mbstowcs() mbtowc()
memchr() memcmp() memcpy() memmove()
memset() mktime() on_exit() perror()
printf() putc() putchar() puts()
qsort() raise() rand() realloc()
realloc_nocopy() remove() rename() rewind()
scanf() setbuf() setlocale() setvbuf()
signal() snprintf() sprintf() srand()
sscanf() stccpy() stcd_l() stch_l()
stcl_d() stcl_h() stcl_o() stco_l()
stcu_d() stpblk() stpcpy() stpsym()
strcasecmp() strcasestr() strcat() strchr()
strcmp() strcoll() strcpy() strcspn()
strdup() strerror() strftime() strlcat()
strlcpy() strlen() strlwr() strncasecmp()
strncat() strncmp() strncpy() strndup()
strnlen() strpbrk() strrchr() strrev()
strsep() strspn() strstr() strtod()
strtof() strtoimax() strtok() strtok_r()
strtol() strtold() strtoll() strtoul()
strtoull() strtoumax() strupr() strxfrm()
system() time() tmpfile() tmpnam()
ungetc() vasprintf() vfprintf() vfscanf()
vprintf() vscanf() vsnprintf() vsprintf()
vsscanf() wcscat() wcscmp() wcscpy()
wcslen() wcsncmp() wcsncpy() wcstombs()
wctomb()      

--background_C99--

Notes

On AROS standardized C interfaces are implemented with a few shared
libraries. A distinction is made between a standard ANSI-C/ISO-C
part and a POSIX emulation layer.
Here the ANSI-C/ISO-C part is documented.

The ANSI-C/ISO-C part is implemented by the stdc.library and the
stdcio.library shared libraries. The former implements the part that
only depends on exec.library; the latter the parts that depends on
other libraries like dos.library and contains mostly I/O related
functions.
Currently both libraries are disk based but the plan is in the future
put stdc.library in ROM and be initialized right after exec so that
all modules, also those in ROM can use it. stdcio.library will likely
stay disk based.
Purpose of these libraries is to provide a base implementation that
can be used by compilers. Compilers are free to override functions
with their own implementation.

The reference used for the developing the two libraries is the ISO/IEC
standard document ISO/IEC 9899:1999 also known as C99. Not all functions
are implemented but for each function defined in the standard a place
in the library is reserved. The order of the functions in the library
lookup table is based on the order that they are defined in the standard
document.

Not all functions are implemented. Not implemented functions either
are not available in the library at all or just a stub function is
provided. The latter can be used to get programs running without having
a proper implementation of a function. Of course target should be to
have in the end all functions implemented.
Consult the include files and the autodocs to see which functions are
not (fully) implemented.

The include files provided for the C99 code implement a proper
separation of the include files. The includes should only define the
prototypes as defined by the standard. This means includes like
proto/stdc.h or proto/stdcio.h should not be included in the standard
C99 include files. Developers improving or extending these libraries
should keep this in mind.

In order to use the stdc.library programs need to properly initialize
the library using the __stdc_progam_startup() and __stdc_program_end()
functions. It is assumed that this is taken care of by the startup
code provided by the compiler.

See also

posixc.library/--background_posixc--


--background_locale--

Notes

Currently no real locale support is provided by stdc.library. All locale
related functions have a minimal implementation assuming only a "C"
locale.
Implementing proper locale support will need careful development to have
a consistent integration with locale.library. People with ideas can
always post on the AROS development mailing list.

See also

locale.h --background_wchar-- --background_c99--


--background_string--

Notes

Contrary to the other include files; almost all string functions are
made part of stdc.library include the POSIX and the SAS/C ones.
These string functions are most of the small and don't depend on other
code. Doing it this way avoids having code that only uses non C99 string
functions having a dependency on posixc.library.

See also

--background_locale-- --background_c99--


--background_wchar--

Notes

wchar.h/wctype.h is not implemented by stdc.library. It is left to
the compiler to provide their implementation of wchar support.
No system functions should thus at the moment use wchar as
implementation is compiler dependent.

See also

--background_locale-- --background_c99--


__stdc_assert()

Synopsis

void __stdc_assert(
   const char * expr,
   const char * file,
   unsigned int line)

Function

This is a function that is used for implementation of the C99 assert()
function.

Inputs

expr - The expression to evaluate. The type of the expression does
        not matter, only if its zero/NULL or not.
file - Name of the source file.
line - Line number of assert() call.

Result

The function doesn't return.

Notes

Different versions of this function are available. This function
is used when a program is using stdc.library but not
stdcio.library or posixc.library.
Because no normal DOS file I/O is available an attempt will be made
to display the assertion in a requester and thus deviating from the
C99 standard that says it to go to the error stream.

__stdc_get_errorptr()

Synopsis

int *__stdc_get_errorptr(
   void)

Function

This function gets the pointer to store error return value for
program exit.

Inputs

-

Result

pointer to return value

__stdc_gmtoffset()

Synopsis

int __stdc_gmtoffset(
   void)

Result

The offset to GMT in minutes

Notes

Will return 0 when locale.library is not loaded into memory yet.

__stdc_jmp2exit()

Synopsis

void __stdc_jmp2exit(
   int normal,
   int retcode)

Function

This function directly jumps to the exit of a program.

Inputs

normal - Indicates if exit is normal or not. When it is abnormal no
         atexit functions will be called.
retcode - the return code for the program.

Result

-

Notes

In normal operation this function does not return.
If this function returns it means that this function was called in a
context where jmp_buf for exit was not initialized. Likely cause is
a module that opened stdc.library.
Be sure to capture this situation.

__stdc_program_end()

Synopsis

void __stdc_program_end(
   void)

Function

This function is to be called when main() has returned or after
program has exited. This allows to stdc.library to do some
cleanup that can't be done during closing of the library.

Inputs

-

Result

-

Notes

This function is normally called by the startup code so one
should not need to do it oneself.

TODO: Maybe this function should be implemented using Tags so that
functionality can be extended in the future without breaking backwards
compatibility.

__stdc_program_startup()

Synopsis

void __stdc_program_startup(
   jmp_buf exitjmp,
   int *errorptr)

Function

This is called during program startup and before calling main.
This is to allow stdc.library to do some initialization that couldn't
be done when opening the library.

Inputs

exitjmp - jmp_buf to jump to to exit the program
errorptr - pointer to store return value of program

Result

-

Notes

This function is normally called by the startup code so one
should not need to do it oneself.

TODO: Maybe this function should be implemented using Tags so that
functionality can be extended in the future without breaking backwards
compatibility.

__stdc_set_errorptr()

Synopsis

int *__stdc_set_errorptr(
   int *errorptr)

Function

This function sets the pointer to store error return value for
program exit.

Inputs

errorptr - new pointer to return value

Result

old pointer to return value

__stdc_set_exitjmp()

Synopsis

void __stdc_set_exitjmp(
   jmp_buf exitjmp,
   jmp_buf previousjmp)

Function

This function set the jmp_buf to use for directly exiting current
program.

Inputs

exitjmp - new jmp_buf for exiting

Result

previous jmp_buf for exiting

__stdc_strerror()

Synopsis

char * __stdc_strerror(
   int n)

Function

Returns a readable string for an error number in errno.

Inputs

n - The contents of errno or a #define from errno.h

Result

A string describing the error.

Notes

This functions only handles the error codes needed by C99 and the ones
used in stdc.library. This function is aliased as strerror() in
libstdc.a
Other libraries may override this function by providing this function
also in their libxxx.a file. They can internally call __stdc_strerror
to get the strings for the errors handled by this function.

__stdcio_assert()

Synopsis

void __stdcio_assert(
   const char * expr,
   const char * file,
   unsigned int line)

Function

This is a function that is used for implementation of the C99 assert()
function.

Inputs

expr - The expression to evaluate. The type of the expression does
        not matter, only if its zero/NULL or not.
file - Name of the source file.
line - Line number of assert() call.

Result

The function doesn't return.

Notes

Different versions of this function are available. This function
is used when a program is using stdcio.library and not
posixc.library.

__stdcio_get_environptr()

Synopsis

char ***__stdcio_get_environptr(
   void)

Function

This function the get pointer to the child environ global variable
currently used by posixc.library.

Inputs

-

Result

environptr - ptr to the child environ variable (== &environ).
             NULL is return if envirion emulation is disabled.

__stdcio_get_envlistptr()

Synopsis

char ***__stdcio_get_envlistptr(
   void)

Inputs

-

Notes

Private - do not use!

__stdcio_set_environptr()

Synopsis

int __stdcio_set_environptr(
   char ***environptr)

Function

This function is called to enable environ emulation mode.

Inputs

environptr - ptr to the child environ variable (== &environ).

Result

0 on fail, other value on success

Notes

This function will enable environ emulation. This means that
all current DOS local variables are converted to the 'var=value'
format and be accessible through char **environ.

Bugs

At the moment only a static list is supported. getenv() and setenv()
don't use this yet so changes done with these functions are not
reflected in environ.
This is still TODO.

__stdcio_set_envlistptr()

Synopsis

int __stdcio_set_envlistptr(
   char ***envlistptr)

Notes

Private - do not use!

__vcformat()

Synopsis

int __vcformat(
   void       * data,
   int       (* outc)(int, void *),
   const char * format,
   va_list      args)

Function

Format a list of arguments and call a function for each char
to print.

Inputs

data - This is passed to the user callback outc as its second argument.
outc - Call this function for every character that should be
        emitted. The function should return EOF on error and
        > 0 otherwise.
format - A printf() format string.
args - A list of arguments for the format string.

Result

The number of characters written.

_Exit()

Synopsis

void _Exit(
   int code)

Function

Terminates the running program immediately. The code is returned to
the program which has called the running program. In contrast to
exit(), this function does not call user exit-handlers added with
atexit() or on_exit(). It does, however, close open filehandles.

Inputs

code - Exit code. 0 for success, other values for failure.

Result

None. This function does not return.

Notes

This function must not be used in a shared library or in a threaded
application.

abort()

Synopsis

void abort(
   void)

Function

Causes abnormal program termination. If there is a signal handler
for SIGABORT, then the handler will be called. If the handler
returns, then the program is aborted anyway.

Inputs

None.

Result

None. This function does not return.

Example

if (fatal_error)
    abort ();

Notes

This function must not be used in a shared library or
in a threaded application.

Bugs

Signal handling is not implemented yet.

abs()

Synopsis

int abs(
   int j)

Function

Compute the absolute value of j.

Inputs

j - A signed integer

Result

The absolute value of j.

Example

// returns 1
abs (1);

// returns 1
abs (-1);

asctime()

Synopsis

char * asctime(
   const struct tm * tm)

Function

The asctime() function converts the broken-down time value tm
into a string.

See asctime_r() for details.

Inputs

tm - The broken down time

Result

A statically allocated buffer with the converted time. Note that
the contents of the buffer might get lost with the call of any of the
date and time functions.

Example

time_t      tt;
struct tm * tm;
char      * str;

// Get time
time (&tt);

// Break time up
tm = localtime (&tt);

// Convert to string
str = asctime (tm);

Notes

The returned string is buffered per stdc.library base.

asctime_r()

Synopsis

char * asctime_r(
   const struct tm * tm,
   char * buf)

Function

The asctime_r() function converts the broken-down time value tm
into a string with this format:

    "Wed Jun 30 21:49:08 1993\n"

Inputs

tm - The broken down time
buf - Buffer of at least 26 characters to store the string in

Result

The pointer passed in buf, containing the converted time. Note that
there is a newline at the end of the buffer.

Example

time_t    tt;
struct tm tm;
char      str[26];

// Get time
time (&tt);

// Break time up
localtime (&tt, &tm);

// Convert to string
asctime (&tm, str);

asprintf()

Synopsis

int asprintf(
   char **restrict str, const char *restrict format, ...)

Function

Analog of sprintf, except that sotrage is allocated for a string
large enough to hold the output including the terminating null
byte

Inputs

str - Where to store the pointer for the allocated string.
format - A printf() format string.
... - Arguments for the format string

Result

The number of characters written, or EOF on error.

assert()

Synopsis

void assert(
   expr)

Function

Evaluates the expression expr and if it's FALSE or NULL, then
printf a message and aborts the program. The message will
contain the expression, the name of the file with the assert
in it and the line in the file.

Inputs

expr - The expression to evaluate. The type of the expression does
        not matter, only if it's zero/NULL or not.

Result

The function doesn't return.

Example

// Make sure that x equals 1
assert (x==1);

Notes

Normally the output is sent to stderr and thus this code should
only be called from processes with the context of the process
available.
In low level modules it is advised to use the ASSERT() macro for
aros/debug.h.
As a last resort one can use the normal assert() macro but link
with the kernelassert static link library to get a version that
also outputs to kernel debug output.
With this assert also an Alert will be generated in place of abort of
the program.

atexit()

Synopsis

int atexit(
   void (*func)(void))

Function

Registers the given function to be called at normal
process termination.

Inputs

func - function to be called.

atof()

Synopsis

double atof(
   const char * str)

Function

Convert a string of digits into a double.

Inputs

str - The string which should be converted. Leading
        whitespace are ignored. The number may be prefixed
        by a '+' or '-'.

Result

The value of string str.

atoi()

Synopsis

int atoi(
   const char * str)

Function

Convert a string of digits into an integer.

Inputs

str - The string which should be converted. Leading
        whitespace are ignored. The number may be prefixed
        by a '+' or '-'.

Result

The value of string str.

Example

// returns 1
atoi ("  \t +1");

// returns 1
atoi ("1");

// returns -1
atoi ("  \n -1");

atol()

Synopsis

long atol(
   const char * str)

Function

Convert a string of digits into an long integer.

Inputs

str - The string which should be converted. Leading
        whitespace are ignored. The number may be prefixed
        by a '+' or '-'.

Result

The value of string str.

Example

// returns 1
atol ("  \t +1");

// returns 1
atol ("1");

// returns -1
atol ("  \n -1");

atoll()

Synopsis

long long atoll(
   const char * str)

Function

Convert a string of digits into an long long integer.

Inputs

str - The string which should be converted. Leading
        whitespace are ignored. The number may be prefixed
        by a '+' or '-'.

Result

The value of string str.

Example

// returns 1
atoll ("  \t +1");

// returns 1
atoll ("1");

// returns -1
atoll ("  \n -1");

bsearch()

Synopsis

void * bsearch(
   const void * key,
   const void * base,
   size_t       count,
   size_t       size,
   int       (* comparefunction)(const void *, const void *))

Function

Search in a sorted array for an entry key.

Inputs

key - Look for this key.
base - This is the address of the first element in the array
        to be searched. Note that the array *must* be sorted.
count - The number of elements in the array
size - The size of one element
comparefunction - The function which is called when two elements
        must be compared. The function gets the addresses of two
        elements of the array and must return 0 is both are equal,
        < 0 if the first element is less than the second and > 0
        otherwise.

Result

A pointer to the element which equals key in the array or NULL if
no such element could be found.

calloc()

Synopsis

void * calloc(
   size_t count,
   size_t size)

Function

Allocate size bytes of memory, clears the memory (sets all bytes to
0) and returns the address of the first byte.

Inputs

count - How many time size
size - How much memory to allocate.

Result

A pointer to the allocated memory or NULL. If you don't need the
memory anymore, you can pass this pointer to free(). If you don't,
the memory will be freed for you when the application exits.

clearerr()

Synopsis

void clearerr(
   FILE * stream)

Function

Clear EOF and error flag in a stream. You must call this for
example after you have read the file until EOF, then appended
something to it and want to continue reading.

Inputs

stream - The stream to be reset.

Result

None.

clock()

Synopsis

clock_t clock(
   void)

Function

clock() returns an approximation of the time passed since
the program was started

Result

The time passed in CLOCKS_PER_SEC units. To get the
number of seconds divide by CLOCKS_PER_SEC.

Notes

Reference point is set when stdc.library is opened.
If you use the function from another shared library the reference
point is thus when this library opened stdc.library

ctime()

Synopsis

char * ctime(
   const time_t * tt)

Function

The ctime() function converts the broken-down time value tt
into a string.

See ctime_r() for details.

Inputs

tt - Convert this time.

Result

A statically allocated buffer with the converted time. Note that
the contents of the buffer might get lost with the call of any of the
date and time functions.

Example

time_t tt;
char * str;

// Get time
time (&tt);

// Convert to string
str = ctime (&tt);

Notes

This function must not be used in a shared library or
in a threaded application. Use ctime_r() instead.

ctime_r()

Synopsis

char * ctime_r(
   const time_t * tt,
   char * buf)

Function

The ctime_r() function converts the time value tt into a string with
this format:

    "Wed Jun 30 21:49:08 1993\n"

Inputs

tt - Convert this time.
buf - Buffer of at least 26 characters to store the string in

Result

The pointer passed in buf, containing the converted time. Note that
there is a newline at the end of the buffer.

Example

time_t tt;
char str[26];

// Get time
time (&tt);

// Convert to string
ctime (&tt, str);

difftime()

Synopsis

double difftime(
   time_t time2,
   time_t time1)

Function

difftime() returns the number of seconds elapsed between
time time2 and time time1.

Inputs

time2 - time value from which time1 is subtracted
time1 - time value that is subtracted from time2

Result

The number of seconds elapsed in double precision.

Example

time_t tt1, tt2;
double secs;

time (&tt1);
...
time (&tt2);

secs = difftime(tt2, tt1);

div()

Synopsis

div_t div(
   int numer,
   int denom)

Function

Compute quotient en remainder of two int variables

Inputs

numer = the numerator
denom = the denominator

Result

a struct with two ints quot and rem with
quot = numer / denom and rem = numer % denom.

typedef struct div_t {
    int quot;
    int rem;
} div_t;

NOTES


exit()

Synopsis

void exit(
   int code)

Function

Terminates the running program. The code is returned to the
program which has called the running program.

Inputs

code - Exit code. 0 for success, other values for failure.

Result

None. This function does not return.

Notes

This function must not be used in a shared library or
in a threaded application.
EXAMPLE
if (no_problems)
exit (0);
if (warning)
exit (5);
if (error)
exit (10);
if (fatal)
exit (20);

fclose()

Synopsis

int fclose(
   FILE * stream)

Function

Closes a stream.

Inputs

stream - Stream to close.

Result

Upon successful completion 0 is returned. Otherwise, EOF is
returned and the global variable errno is set to indicate the
error. In either case no further access to the stream is possible.

feof()

Synopsis

int feof(
   FILE * stream)

Function

Test the EOF-Flag of a stream. This flag is set automatically by
any function which recognises EOF. To clear it, call clearerr().

Inputs

stream - The stream to be tested.

Result

!= 0, if the stream is at the end of the file, 0 otherwise.

ferror()

Synopsis

int ferror(
   FILE * stream)

Function

Test the error flag of a stream. This flag is set automatically by
any function that detects an error. To clear it, call clearerr().

Inputs

stream - The stream to be tested.

Result

!= 0, if the stream had an error, 0 otherwise.

fflush()

Synopsis

int fflush(
   FILE * stream)

Function

Flush a stream. If the stream is an input stream, then the stream
is synchronized for unbuffered I/O. If the stream is an output
stream, then any buffered data is written.

Inputs

stream - Flush this stream. May be NULL. In this case, all
        output streams are flushed.

Result

0 on success or EOF on error.

fgetc()

Synopsis

int fgetc(
   FILE * stream)

Function

Read one character from the stream. If there is no character
available or an error occurred, the function returns EOF.

Inputs

stream - Read from this stream

Result

The character read or EOF on end of file or error.
If EOF is returned feof() and ferror() indicate if it was an
end-of-file situation or an error.

fgetpos()

Synopsis

int fgetpos(
   FILE   * stream,
   fpos_t * pos)

Function

Get the current position in a stream. This function is equivalent
to ftell(). However, on some systems fpos_t may be a complex
structure, so this routine may be the only way to portably
get the position of a stream.

Inputs

stream - The stream to get the position from.
pos - Pointer to the fpos_t position structure to fill.

Result

0 on success and -1 on error. If an error occurred, the global
variable errno is set.

fgets()

Synopsis

char * fgets(
   char * buffer,
   int    size,
   FILE * stream)

Function

Read one line of characters from the stream into the buffer.
Reading will stop, when a newline ('\n') is encountered, EOF
or when the buffer is full. If a newline is read, then it is
put into the buffer. The last character in the buffer is always
'\0' (Therefore at most size-1 characters can be read in one go).

Inputs

buffer - Write characters into this buffer
size - This is the size of the buffer in characters.
stream - Read from this stream

Result

buffer or NULL in case of an error or EOF.

Example

// Read a file line by line
char line[256];

// Read until EOF
while (fgets (line, sizeof (line), fh))
{
    // Evaluate the line
}

fopen()

Synopsis

FILE * fopen(
   const char * restrict pathname,
   const char * restrict mode)

Function

Opens a file with the specified name in the specified mode.

Inputs

pathname - Path and filename of the file you want to open.
mode - How to open the file:

        r: Open for reading. The stream is positioned at the
                beginning of the file.

        r+: Open for reading and writing. The stream is positioned
                at the beginning of the file.

        w: Open for writing. If the file doesn't exist, then
                it is created. If it does already exist, then
                it is truncated. The stream is positioned at the
                beginning of the file.

        w+: Open for reading and writing. If the file doesn't
                exist, then it is created. If it does already
                exist, then it is truncated. The stream is
                positioned at the beginning of the file.

        a: Open for writing. If the file doesn't exist, then
                it is created. The stream is positioned at the
                end of the file.

        a+: Open for reading and writing. If the file doesn't
                exist, then it is created. The stream is positioned
                at the end of the file.

        b: Open in binary more. This has no effect and is ignored.

Result

A pointer to a FILE handle or NULL in case of an error. When NULL
is returned, then errno is set to indicate the error.

Bugs

Currently errno is not set on error.

fprintf()

Synopsis

int fprintf(
   FILE       * restrict fh,
   const char * restrict format,
   ...)

Function

Format a string with the specified arguments and write it to
the stream.

Inputs

fh - Write to this stream
format - How to format the arguments
... - The additional arguments

Result

The number of characters written to the stream or EOF on error.

fputc()

Synopsis

int fputc(
   int    c,
   FILE * stream)

Function

Write one character to the specified stream.

Inputs

c - The character to output
stream - The character is written to this stream

Result

The character written or EOF on error.

fputs()

Synopsis

int fputs(
   const char * str,
   FILE       * stream)

Function

Write a string to the specified stream.

Inputs

str - Output this string...
fh - ...to this stream

Result

> 0 on success and EOF on error.

fread()

Synopsis

size_t fread(
   void * restrict buf,
   size_t size,
   size_t nblocks,
   FILE * restrict stream)

Function

Read an amount of bytes from a stream.

Inputs

buf - The buffer to read the bytes into
size - Size of one block to read
nblocks - The number of blocks to read
stream - Read from this stream

Result

The number of blocks read. This may range from 0 when the stream
contains no more blocks up to nblocks. In case of an error, 0 is
returned.

free()

Synopsis

void free(
   void * memory)

Function

Return memory allocated with malloc() or a similar function to the
system.

Inputs

memory - The result of the previous call to malloc(), etc. or
        NULL.

Result

None.

freopen()

Synopsis

FILE *freopen(
   const char * restrict path,
   const char * restrict mode,
   FILE       * restrict stream
   )

Function

Opens the  file whose name is the string pointed to by path  and
associates  the  stream  pointed to by stream with it.

Inputs

path   - the file to open, NULL to only change the mode of the stream.
mode   - Mode to open file, see fopen for description of the string.
         When path is NULL end-of-file and error indicator will be
         cleared and indication if stream is read and/or write.
         No change to position in file or no truncation will be
         performed.
stream - the stream to which the file will be associated.

Result

NULL on error or stream. When NULL is returned input stream is
not changed.

fscanf()

Synopsis

int fscanf(
   FILE       * restrict fh,
   const char * restrict format,
   ...)

Function

Scan a string with the specified arguments and write the results
in the specified parameters.

Inputs

fh - Read from this stream
format - How to convert the input into the arguments
... - Write the result in these arguments

Result

The number of converted arguments.

fseek()

Synopsis

int fseek(
   FILE * stream,
   long   offset,
   int    whence)

Function

Change the current position in a stream.

Inputs

stream - Modify this stream
offset, whence - How to modify the current position. whence
        can be SEEK_SET, then offset is the absolute position
        in the file (0 is the first byte), SEEK_CUR then the
        position will change by offset (ie. -5 means to move
        5 bytes to the beginning of the file) or SEEK_END.
        SEEK_END means that the offset is relative to the
        end of the file (-1 is the last byte and 0 is
        the EOF).

Result

0 on success and -1 on error. If an error occurred, the global
variable errno is set.

Notes

The seek is handled by the files system so effects of what happens
when seeking after end of file may differ between file systems.

Bugs

Not fully compatible with ISO fseek, especially in 'ab' and 'a+b'
modes

fsetpos()

Synopsis

int fsetpos(
   FILE            * stream,
   const fpos_t    * pos)

Function

Change the current position in a stream. This function is equivalent
to fseek() with whence set to SEEK_SET. However, on some systems
fpos_t may be a complex structure, so this routine may be the only
way to portably reposition a stream.

Inputs

stream - Modify this stream
pos - The new position in the stream.

Result

0 on success and -1 on error. If an error occurred, the global
variable errno is set.

ftell()

Synopsis

long int ftell(
   FILE * stream)

Function

Tell the current position in a stream.

Inputs

stream - Obtain position of this stream

Result

The position on success and -1 on error.
If an error occurred, the global variable errno is set.

fwrite()

Synopsis

size_t fwrite(
   const void * restrict   buf,
   size_t                  size,
   size_t                  nblocks,
   FILE * restrict         stream)

Function

Write an amount of bytes to a stream.

Inputs

buf - The buffer to write to the stream
size - Size of one block to write
nblocks - The number of blocks to write
stream - Write to this stream

Result

The number of blocks written. If no error occurred, this is
nblocks. Otherwise examine errno for the reason of the error.

getc()

Synopsis

int getc(
   FILE * stream)

Function

Read one character from the stream. If there is no character
available or an error occurred, the function returns EOF.

Inputs

stream - Read from this stream

Result

The character read or EOF on end of file or error.

getchar()

Synopsis

int getchar(

Function

Read one character from the standard input stream. If there
is no character available or an error occurred, the function
returns EOF.

Result

The character read or EOF on end of file or error.

getenv()

Synopsis

char *getenv(
   const char *name)

Function

Get an environment variable.

Inputs

name - Name of the environment variable.

Result

Pointer to the variable's value, or NULL on failure.
When no memory is available errno will be set to ENOMEM.

Notes

The returned contents of the environment variable is cached per
StdCIOBase. So the returned value is valid and does not change
until a next call to getenv on the same StdCIOBase.

gets()

Synopsis

char * gets(
   char * buffer)

Function

Read one line of characters from the standard input stream into
the buffer. Reading will stop, when a newline ('\n') is encountered,
EOF or when the buffer is full. If a newline is read, then it is
replaced by '\0'. The last character in the buffer is always '\0'.

Inputs

buffer - Write characters into this buffer

Result

buffer when successful. NULL in case of an error or when EOF without any
characters read. In the latter case buffer array is unchanged.

Bugs

Never use this function. gets() does not know how large the buffer
is and will continue to store characters past the end of the buffer
if it has not encountered a newline or EOF yet. Use fgets() instead.

gmtime()

Synopsis

struct tm * gmtime(
   const time_t * tt)

Function

The gmtime() function converts the calendar time tt to
broken-down time representation, expressed in Coordinated Universal
Time (UTC).

See gmtime_r() for details.

Inputs

tt - The time to convert

Result

A statically allocated buffer with the broken down time in Coordinated
Universal Time (UTC). Note that the contents of the buffer might get
lost with the call of any of the date and time functions.

Example

time_t      tt;
struct tm * tm;

// Get the time
time (&tt);

// and convert it
tm = gmtime (&tt);

Notes

Resulting tm struct is buffered per stdc.library and shared
with localtime().

gmtime_r()

Synopsis

struct tm * gmtime_r(
   const time_t * tt,
   struct tm * tm)

Function

The gmtime_r() function converts the calendar time tt to
broken-down time representation, expressed in Coordinated Universal
Time (UTC).

Inputs

tt - The time to convert
tm - A struct tm to store the result in

Result

The pointer passed in tm, containing the broken down time in
Coordinated Universal Time (UTC).

Example

time_t    tt;
struct tm tm;

// Get the time
time (&tt);

// and convert it
gmtime (&tt, &tm);

imaxabs()

Synopsis

intmax_t imaxabs(
   intmax_t j)

Function

Compute the absolute value of an integer "j".

Result

Return the absolute value.

imaxdiv()

Synopsis

imaxdiv_t imaxdiv(
   intmax_t num, intmax_t denom)

Function

Computes the value num/denom and returns
the quotient and remainder in a structure named imaxdiv_t.

Result

Return quotient and remainder from division.

isalnum()

Synopsis

int isalnum(
   int c)

Function

Test if a character is an alphabetic character or a digit. Works
for all characters between -128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is alphabetic character or a digit, 0 otherwise.

Example

isalnum ('A')    -> true
isalnum ('a')    -> true
isalnum ('0')    -> true
isalnum ('.')    -> false
isalnum ('\n')   -> false
isalnum ('\001') -> false
isalnum (EOF)    -> false

isalpha()

Synopsis

int isalpha(
   int c)

Function

Test if a character is an alphabetic character. Works for all
characters between -128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is an alphabetic character, 0 otherwise.

Example

isalpha ('A')    -> true
isalpha ('a')    -> true
isalpha ('0')    -> false
isalpha ('.')    -> false
isalpha ('\n')   -> false
isalpha ('\001') -> false
isalpha (EOF)    -> false

isascii()

Synopsis

int isascii(
   int c)

Function

Test if a character is an ascii character. Works for all characters
between -128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is an ascii character, 0 otherwise.

Example

isascii ('A')    -> true
isascii ('a')    -> true
isascii ('0')    -> true
isascii ('.')    -> true
isascii ('\n')   -> true
isascii ('\001') -> true
isascii (EOF)    -> false

isblank()

Synopsis

int isblank(
   int c)

Function

Test if a character is a space or a tab. Works for all characters
between -128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is a space or tab, 0 otherwise.

Example

isblank ('A')    -> false
isblank ('a')    -> false
isblank ('0')    -> false
isblank ('.')    -> false
isblank (' ')    -> true
isblank ('\n')   -> false
isblank ('\001') -> false
isblank (EOF)    -> false

iscntrl()

Synopsis

int iscntrl(
   int c)

Function

Test if a character is a control character. Works for all
characters between -128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is a control character, 0 otherwise.

Example

iscntrl ('A')    -> false
iscntrl ('a')    -> false
iscntrl ('0')    -> false
iscntrl ('.')    -> false
iscntrl ('\n')   -> true
iscntrl ('\001') -> true
iscntrl (EOF)    -> false

isdigit()

Synopsis

int isdigit(
   int c)

Function

Test if a character is a digit. Works for all characters between
-128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is a digit, 0 otherwise.

Example

isdigit ('A')    -> false
isdigit ('a')    -> false
isdigit ('0')    -> true
isdigit ('.')    -> false
isdigit ('\n')   -> false
isdigit ('\001') -> false
isdigit (EOF)    -> false

isgraph()

Synopsis

int isgraph(
   int c)

Function

Test if a character is a printable character but no whitespace.
Works for all characters between -128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is a printable character but no whitespace, 0
otherwise.

Example

isgraph ('A')    -> true
isgraph ('a')    -> true
isgraph ('0')    -> true
isgraph ('.')    -> true
isgraph ('\n')   -> false
isgraph ('\001') -> false
isgraph (EOF)    -> false

islower()

Synopsis

int islower(
   int c)

Function

Test if a character is lowercase. Works for all characters between
-128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is lowercase, 0 otherwise.

Example

islower ('A')    -> false
islower ('a')    -> true
islower ('0')    -> false
islower ('.')    -> false
islower ('\n')   -> false
islower ('\001') -> false
islower (EOF)    -> false

isprint()

Synopsis

int isprint(
   int c)

Function

Test if a character is a printable character. Works for all
characters between -128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is a printable character, 0 otherwise.

Example

isprint ('A')    -> true
isprint ('a')    -> true
isprint ('0')    -> true
isprint ('.')    -> true
isprint ('\n')   -> true
isprint ('\001') -> false
isprint (EOF)    -> false

ispunct()

Synopsis

int ispunct(
   int c)

Function

Test if a character is printable but not alphanumeric. Works for
all characters between -128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is printable but not alphanumeric, 0
otherwise.

Example

ispunct ('A')    -> false
ispunct ('a')    -> false
ispunct ('0')    -> false
ispunct ('.')    -> true
ispunct ('\n')   -> false
ispunct ('\001') -> false
ispunct (EOF)    -> false

isspace()

Synopsis

int isspace(
   int c)

Function

Test if a character is whitespace. Works for all characters between
-128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is whitespace, 0 otherwise.

Example

isspace ('A')    -> false
isspace ('a')    -> false
isspace ('0')    -> false
isspace ('.')    -> false
isspace ('\n')   -> true
isspace ('\001') -> false
isspace (EOF)    -> false

isupper()

Synopsis

int isupper(
   int c)

Function

Test if a character is uppercase. Works for all characters between
-128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is uppercase, 0 otherwise.

Example

isupper ('A')    -> true
isupper ('a')    -> false
isupper ('0')    -> false
isupper ('.')    -> false
isupper ('\n')   -> false
isupper ('\001') -> false
isupper (EOF)    -> false

isxdigit()

Synopsis

int isxdigit(
   int c)

Function

Test if a character is a hexadecimal digit. Works for all
characters between -128 and 255 inclusive both.

Inputs

c - The character to test.

Result

!= 0 if the character is a hexadecimal digit, 0 otherwise.

Example

isxdigit ('A')    -> true
isxdigit ('a')    -> true
isxdigit ('x')    -> false
isxdigit ('0')    -> true
isxdigit ('.')    -> false
isxdigit ('\n')   -> false
isxdigit ('\001') -> false
isxdigit (EOF)    -> false

labs()

Synopsis

long labs(
   long j)

Function

Compute the absolute value of j.

Inputs

j - A signed long

Result

The absolute value of j.

Example

// returns 1
labs (1L);

// returns 1
labs (-1L);

ldiv()

Synopsis

ldiv_t ldiv(
   long int numer,
   long int denom)

Function

Compute quotient en remainder of two long variables

Inputs

numer = the numerator
denom = the denominator

Result

a struct with two long ints quot and rem with
quot = numer / denom and rem = numer % denom.

typedef struct ldiv_t {
    long int quot;
    long int rem;
} ldiv_t;

llabs()

Synopsis

long long llabs(
   long long j)

Function

Compute the absolute value of j.

Inputs

j - A signed long long

Result

The absolute value of j.

Example

// returns 1
labs (1L);

// returns 1
labs (-1L);

lldiv()

Synopsis

lldiv_t lldiv(
   long long int numer,
   long long int denom)

Function

Compute quotient en remainder of two long long variables

Inputs

numer = the numerator
denom = the denominator

Result

a struct with two long ints quot and rem with
quot = numer / denom and rem = numer % denom.

typedef struct lldiv_t {
    long long int quot;
    long long int rem;
} lldiv_t;

localeconv()

Synopsis

struct lconv *localeconv(
   void)

Function

The localeconv function sets the components of an object with type
struct lconv with values appropriate for the formatting of numeric
quantities (monetary and otherwise) according to the rules of the
current locale.

Inputs

-

Result

The lconv struct

Notes

stdc.library only support "C" locale so always the same data
is returned.

localtime()

Synopsis

struct tm * localtime(
   const time_t * tt)

Function

Splits the system time in seconds into a structure.

See localtime_r() for details.

Inputs

tt - A time in seconds from the 1. Jan 1970

Result

A statically allocated buffer with the broken up time. Note that
the contents of the buffer might get lost with the call of any of
the date and time functions.

Example

time_t      tt;
struct tm * tm;

// Get time
time (&tt);

// Break time up
tm = localtime (&tt);

Notes

Resulting tm struct is buffered per stdc.library and shared
with gmtime().

localtime_r()

Synopsis

struct tm * localtime_r(
   const time_t * tt,
   struct tm * tm)

Function

Splits the system time in seconds into a structure.
The members of the tm structure are:

tm_sec - The number of seconds after the minute, normally in
         the range 0 to 59, but can be up to 61 to allow for leap
         seconds.

tm_min - The number of minutes after the hour, in the range 0 to 59.

tm_hour - The number of hours past midnight, in the range 0 to 23.

tm_mday - The day of the month, in the range 1 to 31.

tm_mon - The number of months since January, in the range 0 to 11.

tm_year - The number of years since 1900.

tm_wday - The number of days since Sunday, in the range 0 to 6.

tm_yday - The number of days since January 1, in the range  0 to 365.

tm_isdst - A flag that indicates whether daylight saving time
           is in effect at the time described. The value is positive
           if daylight saving time is in effect, zero if it is not,
           and negative if the information is not available.

Inputs

tt - A time in seconds from the 1. Jan 1970
tm - A struct tm to store the result in

Result

The pointer passed in tm.

Example

time_t    tt;
struct tm tm;

// Get time
time (&tt);

// Break time up
localtime_r (&tt, &tm);

malloc()

Synopsis

void *malloc(
   size_t size)

Function

Allocate size bytes of memory and return the address of the
first byte.

Inputs

size - How much memory to allocate.

Result

A pointer to the allocated memory or NULL. If you don't need the
memory anymore, you can pass this pointer to free(). If you don't,
the memory will be freed for you when the application exits.

malloc_align()

Synopsis

void *malloc_align(
   size_t size,
   size_t alignment)

Function

Allocate aligned memory.

Inputs

size - How much memory to allocate.
alignment - Alignment of allocated memory. The address of the
            allocated memory will be a multiple of this value, which
            must be a power of two and a multiple of sizeof(void *).

Result

A pointer to the allocated memory or NULL.

Notes

errno is set to EINVAL if the alignment parameter was not a power of
two, or was not a multiple of sizeof(void *).
errno is set to ENOMEM if there was insufficient memory to fulfill
the request.
Memory allocated by malloc_align() should be freed with free(). If
not, it will be freed when the program terminates.

This function is AROS specific.

mblen()

Synopsis

int mblen(
   const char *s,
   size_t n)

Function

This function returns the number of bytes of the next multi-byte
character.

Inputs

s: string pointer to look at next multi-byte character.
n: The maximum number of bytes to look at.

Result

if s is not NULL will return the length in bytes of the next
multi-byte character in s; 0 is return when it is a NULL
byte character; -1 if it is not a valid multi-byte character.
If s is NULL zero or non-zero is returned when multi-byte encodings
resp. don't or do have state-dependent encodings.

Notes

stdc.library currently only implements the "C" locale
This means that either 0 or 1 is returned when s is not NULL.

mbstowcs()

Synopsis

size_t mbstowcs(
   wchar_t * restrict pwcs,
   const char * restrict s,
   size_t n)

Function

C99 function mbstowcs.

Notes

stdc.library currently only implements "C" locale.

mbtowc()

Synopsis

int mbtowc(
   wchar_t * restrict pwc,
   const char * restrict s,
   size_t n)

Function

C99 mbtowc function; a function to convert one multi-byte character
to a wchar_t character and/or to determine the number of bytes for the
next multi-byte char.

Inputs

pwc: pointer wide char string to put converted char in. When NULL
     no char will be converted.
s: pointer to multi-byte char as input
n: maximum of bytes to look at for the multi-byte char.

Result

If s is not NULL the function returns the number of bytes the next
multi-byte character is made of; 0 if the char pointed to is NULL or
-1 if it is not a valid multi-byte char.
If s is NULL the function return zero or non-zero when multi-byte chars
resp. don't or do have state-dependent encodings.

Notes

stdc.library currently only supports "C" locale
This means that the function returns 0 when s is NULL and only 0, 1 or -1
when s is not NULL.

memchr()

Synopsis

void * memchr(
   const void * mem,
   int          c,
   size_t       n)

Function

Locate the first occurrence of c which is converted to an unsigned
char in the first n bytes of the memory pointed to by mem.

Inputs

mem - pointer to memory that is searched for c
  c - the character to search for
  n - how many bytes to search through starting at mem

Result

pointer to the located byte or null if c was not found

memcmp()

Synopsis

int memcmp(
   const void * s1,
   const void * s2,
   size_t       n)

Function

Calculate s1 - s2 for the n bytes after s1 and s2 and stop when
the difference is not 0.

Inputs

s1, s2 - Begin of the memory areas to compare
n - The number of bytes to compare

Result

The difference of the memory areas. The difference is 0, if both
are equal, < 0 if s1 < s2 and > 0 if s1 > s2. Note that it may be
greater then 1 or less than -1.

Notes

This function is not part of a library and may thus be called
any time.

memcpy()

Synopsis

void *memcpy(
   void * restrict dst0,
   const void * restrict src0,
   size_t length)

Function

Copy a block of memory; handling of overlapping regions is not
guaranteed.

Inputs

dst0: destination for copy
src0: source for copy
length: number of bytes to copy

Result

dst0

Notes

stdc.library/memcpy() is an alias to stdc.library/memmove()
So overlapping regions are handled OK if this function is used.

memmove()

Synopsis

void *memmove(
   void *dst0,
   const void *src0,
   size_t length)

Function

Copy a block of memory, handling overlap.

Inputs

dst0: destination for copy
src0: source for copy
length: number of bytes to copy

Result

dst0

memset()

Synopsis

void * memset(
   void * dest,
   int    c,
   size_t count)

Function

Fill the memory at dest with count times c.

Inputs

dest - The first byte of the destination area in memory
c - The byte to fill memory with
count - How many bytes to write

Result

dest.

mktime()

Synopsis

time_t mktime(
   struct tm * utim)

Function

The mktime() function converts the broken-down time utim to
calendar time representation.

Inputs

utim - The broken-down time to convert

Result

The converted calendar time

Example

time_t      tt;
struct tm * tm;

//Computation which results in a tm
tm = ...

// and convert it
tt = mktime (tm);

Bugs

At the moment sanity check is not performed nor a normalization on the
structure is done

on_exit()

Synopsis

int on_exit(
   void (*func)(int, void *),
   void *arg)

perror()

Synopsis

void perror(
   const char *string
   )

Function

looks up the language-dependent error message string affiliated with an error
number and writes it, followed by a newline, to the standard error stream.

Inputs

string - the string to prepend the error message. If NULL only the error
         message will be printed, otherwise the error message will be
         separated from string by a colon.

printf()

Synopsis

int printf(
   const char * restrict format,
   ...)

Function

Formats a list of arguments and prints them to standard out.

The format string is composed of zero or more directives: ordinary
characters (not %), which are copied unchanged to the output
stream; and conversion specifications, each of which results in
fetching zero or more subsequent arguments Each conversion
specification is introduced by the character %. The arguments must
correspond properly (after type promotion) with the conversion
specifier. After the %, the following appear in sequence:

\begin{itemize}
\item Zero or more of the following flags:

\begin{description}
\item{#} specifying that the value should be converted to an
``alternate form''. For c, d, i, n, p, s, and u conversions, this
option has no effect. For o conversions, the precision of the
number is increased to force the first character of the output
string to a zero (except if a zero value is printed with an
explicit precision of zero). For x and X conversions, a non-zero
result has the string `0x' (or `0X' for X conversions) prepended to
it. For e, E, f, g, and G conversions, the result will always
contain a decimal point, even if no digits follow it (normally, a
decimal point appears in the results of those conversions only if a
digit follows). For g and G conversions, trailing zeros are not
removed from the result as they would otherwise be.

\item{0} specifying zero padding. For all conversions except n, the
converted value is padded on the left with zeros rather than
blanks. If a precision is given with a numeric conversion (d, i, o,
u, i, x, and X), the 0 flag is ignored.

\item{-} (a negative field width flag) indicates the converted
value is to be left adjusted on the field boundary. Except for n
conversions, the converted value is padded on the right with
blanks, rather than on the left with blanks or zeros. A -
overrides a 0 if both are given.

\item{ } (a space) specifying that a blank should be left before a
positive number produced by a signed conversion (d, e, E, f, g, G,
or i). + specifying that a sign always be placed before a number
produced by a signed conversion. A + overrides a space if both are
used.

\item{'} specifying that in a numerical argument the output is to
be grouped if the locale information indicates any. Note that many
versions of gcc cannot parse this option and will issue a warning.

\end{description}

\item An optional decimal digit string specifying a minimum field
width. If the converted value has fewer characters than the field
width, it will be padded with spaces on the left (or right, if the
left-adjustment flag has been given) to fill out the field width.

\item An optional precision, in the form of a period (`.') followed
by an optional digit string. If the digit string is omitted, the
precision is taken as zero. This gives the minimum number of digits
to appear for d, i, o, u, x, and X conversions, the number of
digits to appear after the decimal-point for e, E, and f
conversions, the maximum number of significant digits for g and G
conversions, or the maximum number of characters to be printed from
a string for s conversions.

\item The optional character h, specifying that a following d, i,
o, u, x, or X conversion corresponds to a short int or unsigned
short int argument, or that a following n conversion corresponds to
a pointer to a short int argument.

\item The optional character l (ell) specifying that a following d,
i, o, u, x, or X conversion applies to a pointer to a long int or
unsigned long int argument, or that a following n conversion
corresponds to a pointer to a long int argument. Linux provides a
non ANSI compliant use of two l flags as a synonym to q or L. Thus
ll can be used in combination with float conversions. This usage
is, however, strongly discouraged.

\item The character L specifying that a following e, E,
f, g, or G conversion corresponds to a long double
argument, or a following d, i, o, u, x, or X conversion corresponds to a long long argument. Note
that long long is not specified in ANSI C and
therefore not portable to all architectures.

\item The optional character q. This is equivalent to L. See the
STANDARDS and BUGS sections for comments on the use of ll, L, and
q.

\item A Z character specifying that the following integer (d, i, o,
u, i, x, and X), conversion corresponds to a size_t argument.

\item A character that specifies the type of conversion to be
applied.

A field width or precision, or both, may be indicated by an
asterisk `*' instead of a digit string. In this case, an int
argument supplies the field width or precision. A negative field
width is treated as a left adjustment flag followed by a positive
field width; a negative precision is treated as though it were
missing.

The conversion specifiers and their meanings are:

\begin{description}
\item{diouxX} The int (or appropriate variant) argument is
converted to signed decimal (d and i), unsigned octal (o, unsigned
decimal (u, or unsigned hexadecimal (x and X) notation. The letters
abcdef are used for x conversions; the letters ABCDEF are used for
X conversions. The precision, if any, gives the minimum number of
digits that must appear; if the converted value requires fewer
digits, it is padded on the left with zeros.

\item{eE} The double argument is rounded and converted in the style
[<->]d.dddedd where there is one digit before the decimal-point
character and the number of digits after it is equal to the
precision; if the precision is missing, it is taken as 6; if the
precision is zero, no decimal-point character appears. An E
conversion uses the letter E (rather than e) to introduce the
exponent. The exponent always contains at least two digits; if the
value is zero, the exponent is 00.

\item{f} The double argument is rounded and converted to decimal
notation in the style [-]ddd.ddd, where the number of digits after
the decimal-point character is equal to the precision
specification. If the precision is missing, it is taken as 6; if
the precision is explicitly zero, no decimal-point character
appears. If a decimal point appears, at least one digit appears
before it.

\item{g} The double argument is converted in style f or e (or E for
G conversions). The precision specifies the number of significant
digits. If the precision is missing, 6 digits are given; if the
precision is zero, it is treated as 1. Style e is used if the
exponent from its conversion is less than -4 or greater than or
equal to the precision. Trailing zeros are removed from the
fractional part of the result; a decimal point appears only if it
is followed by at least one digit.

\item{c} The int argument is converted to an unsigned char, and the
resulting character is written.

\item{s} The ``char *'' argument is expected to be a pointer to an
array of character type (pointer to a string). Characters from the
array are written up to (but not including) a terminating NUL
character; if a precision is specified, no more than the number
specified are written. If a precision is given, no null character
need be present; if the precision is not specified, or is greater
than the size of the array, the array must contain a terminating
NUL character.

\item{p} The ``void *'' pointer argument is printed in hexadecimal
(as if by %#x or %#lx).

\item{n} The number of characters written so far is stored into the
integer indicated by the ``int *'' (or variant) pointer argument.
No argument is converted.

\item{%} A `%' is written. No argument is converted. The complete
conversion specification is `%%'.

\end{description}
\end{itemize}

In no case does a non-existent or small field width cause
truncation of a field; if the result of a conversion is wider than
the field width, the field is expanded to contain the conversion
result.

Inputs

format - Format string as described above
... - Arguments for the format string

Result

The number of characters written to stdout or EOF on error.

Example

To print a date and time in the form `Sunday, July 3,
10:02', where weekday and month are pointers to strings:

    #include <stdio.h>

    fprintf (stdout, "%s, %s %d, %.2d:%.2d\n",
            weekday, month, day, hour, min);

To print to five decimal places:

    #include <math.h>
    #include <stdio.h>

    fprintf (stdout, "pi = %.5f\n", 4 * atan(1.0));

To allocate a 128 byte string and print into it:

    #include <stdio.h>
    #include <stdlib.h>
    #include <stdarg.h>

    char *newfmt(const char *fmt, ...)
    {
        char *p;
        va_list ap;

        if ((p = malloc(128)) == NULL)
            return (NULL);

        va_start(ap, fmt);

        (void) vsnprintf(p, 128, fmt, ap);

        va_end(ap);

        return (p);
    }

Bugs

All functions are fully ANSI C3.159-1989 conformant, but provide
the additional flags q, Z and ' as well as an additional behavior
of the L and l flags. The latter may be considered to be a bug, as
it changes the behavior of flags defined in ANSI C3.159-1989.

The effect of padding the %p format with zeros (either by the 0
flag or by specifying a precision), and the benign effect (i.e.,
none) of the # flag on %n and %p conversions, as well as
nonsensical combinations such as are not standard; such
combinations should be avoided.

Some combinations of flags defined by ANSI C are not making sense
in ANSI C (e.g. %Ld). While they may have a well-defined behavior
on Linux, this need not to be so on other architectures. Therefore
it usually is better to use flags that are not defined by ANSI C at
all, i.e. use q instead of L in combination with diouxX conversions
or ll. The usage of q is not the same as on BSD 4.4, as it may be
used in float conversions equivalently to L.

Because sprintf and vsprintf assume an infinitely long string,
callers must be careful not to overflow the actual space; this is
often impossible to assure.

putc()

Synopsis

int putc(
   int    c,
   FILE * stream)

Function

Write one character to the specified stream.

Inputs

c - The character to output
stream - The character is written to this stream

Result

The character written or EOF on error.

putchar()

Synopsis

int putchar(
   int c)

Function

Equivalent to fputc(stdout)

puts()

Synopsis

int puts(
   const char * str)

Function

Print a string to stdout. A newline ('\n') is emmitted after the
string.

Inputs

str - Print this string

Result

> 0 on success and EOF on error. On error, the reason is put in
errno.

Example

#include <errno.h>

if (puts ("Hello World.") != EOF)
    fprintf (stderr, "Success");
else
    fprintf (stderr, "Failure: errno=%d", errno);

qsort()

Synopsis

void qsort(
   void * a,
   size_t n,
   size_t es,
   int (* cmp)(const void *, const void *))

Function

Sort the array a. It contains n elements of the size es. Elements
are compares using the function cmp().

Inputs

a - The array to sort
n - The number of elements in the array
es - The size of a single element in the array
cmp - The function which is called when two elements must be
        compared. The function gets the addresses of two elements
        of the array and must return 0 is both are equal, < 0 if
        the first element is less than the second and > 0 otherwise.

Result

None.

Example

// Use this function to compare to stringpointers
int cmp_strptr (const char ** sptr1, const char ** sptr2)
{
    return strcmp (*sptr1, *sptr2);
}

// Sort an array of strings
char ** strings;

// fill the array
strings = malloc (sizeof (char *)*4);
strings[0] = strdup ("h");
strings[1] = strdup ("a");
strings[2] = strdup ("f");
strings[3] = strdup ("d");

// Sort it
qsort (strings, sizeof (char *), 4, (void *)cmp_strptr);

raise()

Synopsis

int raise(
   int signum)

Function

Calls the handler of a signal

Inputs

Signal handler to be called.

Result

0: OK
-1: error calling handler, errno will be set.

Notes

The behavior of raise() follows the BSD semantics.
For each signal the system keeps track of a signal handler is already
being called.
If not, the signal handler is called; when yes this will logged and the
handler will be recalled when the first handler returns. If the a new
handler is registered that one will be used then.

rand()

Synopsis

int rand(
   void)

Function

A random number generator.

Inputs

None.

Result

A pseudo-random integer between 0 and RAND_MAX.

realloc()

Synopsis

void * realloc(
   void * oldmem,
   size_t size)

Function

Change the size of an allocated part of memory. The memory must
have been allocated by malloc() or calloc(). If you reduce the
size, the old contents will be lost. If you enlarge the size,
the new contents will be undefined.

Inputs

oldmem - What you got from malloc() or calloc().
size - The new size.

Result

A pointer to the allocated memory or NULL. If you don't need the
memory anymore, you can pass this pointer to free(). If you don't,
the memory will be freed for you when the application exits.

Notes

If you get NULL, the memory at oldmem will not have been freed and
can still be used.

realloc_nocopy()

Synopsis

void * realloc_nocopy(
   void * oldmem,
   size_t size)

Function

Change the size of an allocated part of memory. The memory must
have been allocated by malloc(), calloc(), realloc() or realloc_nocopy().

The reallocated buffer, unlike with realloc(), is not guaranteed to hold
a copy of the old one.

Inputs

oldmem - What you got from malloc(), calloc(), realloc() or realloc_nocopy().
         If NULL, the function will behave exactly like malloc().
size   - The new size. If 0, the buffer will be freed.

Result

A pointer to the allocated memory or NULL. If you don't need the
memory anymore, you can pass this pointer to free(). If you don't,
the memory will be freed for you when the application exits.

Notes

If you get NULL, the memory at oldmem will not have been freed and
can still be used.

This function is AROS specific.

remove()

Synopsis

int remove(
   const char * pathname)

Function

Deletes a file or directory.

Inputs

pathname - Complete path to the file or directory.

Result

0 on success and -1 on error. In case of an error, errno is set.

rename()

Synopsis

int rename(
   const char * oldpath,
   const char * newpath)

Function

Renames a file or directory.

Inputs

oldpath - Complete path to existing file or directory.
newpath - Complete path to the new file or directory.

Result

0 on success and -1 on error. In case of an error, errno is set.

rewind()

Synopsis

void rewind(
   FILE * stream)

Function

Change the current position in a stream to the beginning.
It also clears the error indication of the stream.

Inputs

stream - Modify this stream

scanf()

Synopsis

int scanf(
   const char * restrict format,
   ...)

Result

The number of converted parameters

setbuf()

Synopsis

void setbuf(
   FILE * restrict stream,
   char * restrict buf)

Function

Sets a buffer associated with a stream.

Inputs

stream: stream to set a buffer for.
buf: if it points to an array of at least size BUFSIZ it will be used
     as a buffer with mode _IOFBF. If it is NULL mode will be set to
     _IONBF

Result

-

setlocale()

Synopsis

char *setlocale(
   int category,
   const char *locale)

Inputs

category - category as defined in locale.h
locale - string representing "C"

Result

The lconv struct

Notes

stdc.library only support "C" locale. So only NULL or
"C" are accepted for locale and this function does not
have an effect.

setvbuf()

Synopsis

int setvbuf(
   FILE *stream,
   char *buf,
   int mode,
   size_t size)

Function

Sets the buffer and the mode associated with a stream.

Inputs

stream: stream to set buffer on
buf: the buffer to be associated, when NULL a buffer will be allocated
     and freed on close or new setvbuf. Should be longword aligned.
mode: mode for buffering
    - _IOFBF: fully buffered
    - _IOLBF: line buffered
    - _IONBF: Not buffered
size: size of the buffer (needs to be at least 208).

Result

0 on success, EOF on error. errno indicated error.
Function fails when size < 208 and buf != NULL.

signal()

Synopsis

__sighandler_t *signal(
   int signum,
   __sighandler_t *handler)

Function

Set signal handler for a signal.

Inputs

signum - the signal number to register a handler for
handler - the signal handler; can be SIG_IGN, SIG_DFL or a function
          pointer that will handle the signal

Result

The old handler that was replaced by the new handler.

Notes

Implemented but no interrupts will be generated like when pressing
Ctrl-C; signal handlers can for now only be called by raise() in the
program itself.

snprintf()

Synopsis

int snprintf(
   char       * str,
   size_t       n,
   const char * format,
   ...)

Function

C99 says:The snprintf function is equivalent to fprintf, except that the output is
written into an array (specified by argument s) rather than to a stream. If
n is zero, nothing is written, and s may be a null pointer. Otherwise,
output characters beyond the n-1st are discarded rather than being written
to the array, and a null character is written at the end of the characters
actually written into the array. If copying takes place between objects
that overlap, the behavior is undefined.

Inputs

str - The formatted string is written into this variable. You
      must make sure that it is large enough to contain the
      result.
n -   At most n characters are written into the string. This
      includes the final 0.
format - Format string as described above
... - Arguments for the format string

Result

The snprintf function returns the number of characters that would have been
written had n been sufficiently large, not counting the terminating null
character, or a negative value if an encoding error occurred. Thus, the
null-terminated output has been completely written if and only if the
returned value is nonnegative and less than n.

sprintf()

Synopsis

int sprintf(
   char       * str,
   const char * format,
   ...)

Function

Formats a list of arguments and writes them into the string str.

Inputs

str - The formatted string is written into this variable. You
        must make sure that it is large enough to contain the
        result.
format - Format string as described above
... - Arguments for the format string

Result

The number of characters written into the string.

Notes

No checks are made that str is large enough for the result.

srand()

Synopsis

void srand(
   unsigned int seed)

Function

Set the starting value for the random number generator rand()
If a seed value is set to a value the same stream of pseudo-random
numbers will be generated by rand() for the same seed value.

Inputs

seed - New start value

Result

None.

Notes

One seed value per stdc.library is kept which normally corresponds
with per task.

sscanf()

Synopsis

int sscanf(
   const char  *str,
   const char  *format,
   ...)

Function

Scan the specified string and convert it into the arguments as
specified by format.

Inputs

str     - The routine examines this string.
format - Format string. See scanf() for a description
...    - Arguments for the result

Result

The number of converted parameters.

stccpy()

Synopsis

size_t stccpy(
   char       * dest,
   const char * src,
   size_t       n)

Function

Copy a string. Works like an assignment "dest=src;". At most
n characters are copied.

Inputs

dest - The string is copied into this variable. Make sure it is
        large enough.
src - This is the new contents of dest.
n - How many characters to copy at most. If the string src is
        smaller than that, only strlen(str)+1 bytes are copied.

Result

The number of copied characters.

Notes

No check is made that dest is large enough for src.
SAS/C specific.

stcd_l()

Synopsis

int stcd_l(
   const char      * in,
   long            * lvalue)

Function

Convert decimal string to a long integer

Inputs

in     - The decimal string to be converted
lvalue - Pointer to long where the result is saved

Result

length of characters converted.
>= 1 means success. 0 means failure.

Notes

SAS/C specific

stch_l()

Synopsis

int stch_l(
   const char      * in,
   long            * lvalue)

Function

Convert hexadecimal string to a long integer

Inputs

in     - The hexadecimal string to be converted
lvalue - Pointer to long where the result is saved

Result

Number of characters converted

Notes

SAS/C specific

stcl_d()

Synopsis

int stcl_d(
   char            * out,
   long        lvalue)

Function

Convert an long integer to a decimal string

Inputs

out     - Result will be put into this string
uivalue - the value to convert

Result

The number of characters written into the string

Notes

SAS/C specific

stcl_h()

Synopsis

int stcl_h(
   char            * out,
   long        lvalue)

Function

Convert an long integer to a hex string

Inputs

out     - Result will be put into this string
uivalue - the value to convert

Result

The number of characters written into the string

Notes

SAS/C specific

stcl_o()

Synopsis

int stcl_o(
   char            * out,
   long        lvalue)

Function

Convert an long integer to an octal string

Inputs

out     - Result will be put into this string
uivalue - the value to convert

Result

The number of characters written into the string

Notes

SAS/C specific

stco_l()

Synopsis

int stco_l(
   const char      * in,
   long            * lvalue)

Function

Convert octal string to a long integer

Inputs

in     - The octal string to be converted
lvalue - Pointer to long where the result is saved

Result

1 means success. 0 means failure.

Notes

SAS/C specific

stcu_d()

Synopsis

int stcu_d(
   char            * out,
   unsigned        uivalue)

Function

Convert an unsigned integer to a decimal string

Inputs

out     - Result will be put into this string
uivalue - the value to convert

Result

The number of characters written into the string

Notes

SAS C specific

stpblk()

Synopsis

char * stpblk(
   const char * str )

Function

Searches for the first non-blank character in a string. A blank
character is defined as one that isspace() treats like one
(ie. spaces, tabs and newlines).

Inputs

str - String to search.

Result

A pointer to the first occurrence of a non-blank character in str.

Example

char *hello = " Hello";
char *empty = "      ";

printf( stpblk( hello ) );
--> Hello

printf( stpblk( empty ) );
-->

printf( "%d", strlen( stpblk( hello ) ) );
--> 5

printf( "%d", strlen( stpblk( empty ) ) );
--> 0

Notes

This function always returns a valid pointer as provided str isn't
NULL. If there are no non-blank characters in the string, a pointer
to the trailing '\0' is returned (ie. an empty string).

stpcpy()

Synopsis

char * stpcpy(
   char       * dest,
   const char * src)

Function

Copy a string returning pointer to its end.

Inputs

dest - The string is copied into this variable. Make sure it is
       large enough.

src - This is the new contents of dest.

Result

pointer to the end of the string dest (address of it's null
character)

Notes

No check is made that dest is large enough for src.

stpsym()

Synopsis

char * stpsym(
   char * str_ptr,
   char * dest_ptr,
   int dest_size)

Function

Searches for a symbol in a string.

Inputs

str_ptr - points to the string to scan

dest_ptr - points to the string where stpsym stores the symbol

dest_size - specifies the size in bytes of *dest_ptr

Result

Pointer to the next character in the string after the symbol.
If stpsym could not find a symbol, it returns str_ptr.

Example

#include <string.h>
#include <stdio.h>

int main(void)
{
    char *text;
    char symbol[10];
    char *r;

    text = "alpha1  2";
    r = stpsym(text,symbol,10);
    printf("%s",symbol);   // prints "alpha1"
}

Notes

A symbol consists of an alphabetic character followed by zero
or more alphanumeric characters.  stpsym() does not skip leading
space characters.

Note that if you want to retrieve a symbol of length n, you need
to ensure that *dest_ptr can accommodate at least n+1 elements,
and that dest_size == n+1.  This extra element is needed for the
terminating null character.

strcasecmp()

Synopsis

int strcasecmp(
   const char * str1,
   const char * str2)

Function

Calculate str1 - str2 ignoring case.

Inputs

str1, str2 - Strings to compare

Result

The difference of the strings. The difference is 0, if both are
equal, < 0 if str1 < str2 and > 0 if str1 > str2. Note that
it may be greater then 1 or less than -1.

Notes

This function is not part of a library and may thus be called
any time.

strcasestr()

Synopsis

char * strcasestr(
   const char * str,
   const char * search)

Function

Searches for a string in a string.

Inputs

str - Search this string
search - Look for this string

Result

A pointer to the first occurrence of search in str or NULL if search
is not found in str.

Example

char buffer[64];

strcpy (buffer, "Hello ");

// This returns a pointer to the first l in buffer.
strcasestr (buffer, "llo ");

// This returns NULL
strcasestr (buffer, "llox");

strcat()

Synopsis

char * strcat(
   char       * dest,
   const char * src)

Function

Concatenates two strings.

Inputs

dest - src is appended to this string. Make sure that there
        is enough room for src.
src - This string is appended to dest

Result

dest.

Example

char buffer[64];

strcpy (buffer, "Hello ");
strcat (buffer, "World.");

// Buffer now contains "Hello World."

Notes

The routine makes no checks if dest is large enough.

strchr()

Synopsis

char * strchr(
   const char * str,
   int          c)

Function

Searches for a character in a string.

Inputs

str - Search this string
c - Look for this character

Result

A pointer to the first occurrence of c in str or NULL if c is not
found in str.

Example

char buffer[64];

strcpy (buffer, "Hello ");

// This returns a pointer to the first l in buffer.
strchr (buffer, 'l');

// This returns NULL
strchr (buffer, 'x');

strcmp()

Synopsis

int strcmp(
   const char * str1,
   const char * str2)

Function

Calculate str1 - str2.

Inputs

str1, str2 - Strings to compare

Result

The difference of the strings. The difference is 0, if both are
equal, < 0 if str1 < str2 and > 0 if str1 > str2. Note that
it may be greater then 1 or less than -1.

Notes

This function is not part of a library and may thus be called
any time.

strcoll()

Synopsis

int strcoll(
   const char * str1,
   const char * str2)

Function

Calculate str1 - str2. The operation is based on strings interpreted
as appropriate for the program's current locale for category LC_COLLATE.

Inputs

str1, str2 - Strings to compare

Result

The difference of the strings. The difference is 0, if both are
equal, < 0 if str1 < str2 and > 0 if str1 > str2. Note that
it may be greater then 1 or less than -1.

Notes

stdc.library only implements "C" locale so strcoll() is equivalent
to strcmp()

strcpy()

Synopsis

char * strcpy(
   char       * dest,
   const char * src)

Function

Copy a string. Works like an assignment "dest=src;".

Inputs

dest - The string is copied into this variable. Make sure it is
        large enough.
src - This is the new contents of dest.

Result

dest.

Notes

No check is made that dest is large enough for src.

strcspn()

Synopsis

size_t strcspn(
   const char * str,
   const char * reject)

Function

Calculates the length of the initial segment of str which consists
entirely of characters not in reject.

Inputs

str - The string to check.
reject - Characters which must not be in str.

Result

Length of the initial segment of str which doesn't contain any
characters from reject.

Example

char buffer[64];

strcpy (buffer, "Hello ");

// Returns 5
strcspn (buffer, " ");

// Returns 0
strcspn (buffer, "H");

strdup()

Synopsis

char * strdup(
   const char * orig)

Function

Create a copy of a string. The copy can be freed with free() or will
be freed when the program ends.

Inputs

str1 - Strings to duplicate

Result

A copy of the string which can be freed with free().

strerror()

Synopsis

char * strerror(
   int n)

Function

Returns a readable string for an error number in errno.

Inputs

n - The contents of errno or a #define from errno.h

Result

A string describing the error.

strftime()

Synopsis

size_t strftime(
   char *s,
   size_t maxsize,
   const char *format,
   const struct tm *timeptr)

Notes

Function does not take localization into account at the moment

strlcat()

Synopsis

size_t strlcat(
   char *dst,
   const char *src,
   size_t siz)

strlcpy()

Synopsis

size_t strlcpy(
   char *dst,
   const char *src,
   size_t siz)

strlen()

Synopsis

size_t strlen(
   const char * ptr)

Function

Calculate the length of a string (without the terminating 0 byte).

Inputs

ptr - The string to get its length for

Result

The length of the string.

strlwr()

Synopsis

char * strlwr(
   char * str)

Function

Converts a string to all lower case characters. Modifies
the given string.

Inputs

str - The string to convert.

Result

The same string buffer is passed back with all characters converted.

strncasecmp()

Synopsis

int strncasecmp(
   const char * str1,
   const char * str2,
   size_t       n)

Function

Calculate str1 - str2 ignoring case. Up to n characters are taken
into account.

Inputs

str1, str2 - Strings to compare

Result

The difference of the strings. The difference is 0, if both are
equal, < 0 if str1 < str2 and > 0 if str1 > str2. Note that
it may be greater then 1 or less than -1.

Notes

This function is not part of a library and may thus be called
any time.

strncat()

Synopsis

char * strncat(
   char       * dest,
   const char * src,
   size_t       n)

Function

Concatenates two strings. If src is longer than n characters, then
only the first n characters are copied.

Inputs

dest - src is appended to this string. Make sure that there
        is enough room for src.
src - This string is appended to dest
n - No more than this number of characters of src are copied.

Result

dest.

Example

char buffer[64];

strcpy (buffer, "Hello ");
strncat (buffer, "World.!!", 6);

// Buffer now contains "Hello World."

Notes

The routine makes no checks if dest is large enough. The size of
dest must be at least strlen(dest)+n+1.

strncmp()

Synopsis

int strncmp(
   const char * str1,
   const char * str2,
   size_t       n)

Function

Calculate str1 - str2 for up to n chars or up to the first 0 byte.

Inputs

str1, str2 - Strings to compare

Result

The difference of the strings. The difference is 0, if both are
equal, < 0 if str1 < str2 and > 0 if str1 > str2. Note that
it may be greater then 1 or less than -1.

Notes

This function is not part of a library and may thus be called
any time.

strncpy()

Synopsis

char * strncpy(
   char       * dest,
   const char * src,
   size_t       n)

Function

Copy a string. Works like an assignment "dest=src;". At most
n characters are copied.

Inputs

dest - The string is copied into this variable. Make sure it is
        large enough.
src - This is the new contents of dest.
n - How many characters to copy at most. If the string src is
        smaller than that, only strlen(str)+1 bytes are copied.

Result

dest.

Notes

No check is made that dest is large enough for src.

strndup()

Synopsis

char * strndup(
   const char *s, size_t n)

Function

Create a copy of a string. The copy can be freed with free() or will
be freed when then program ends. The copy will be at most n character
long, excluding the trailing \000

Inputs

s - String to duplicate
n - Maximum length

Result

A copy of the string which can be freed with free().

strnlen()

Synopsis

size_t strnlen(
   const char * ptr, size_t n)

Function

Calculate the length of a string (without the terminating 0 byte).

Inputs

ptr - The string to get its length for
n - The max length

Result

The length of the string.

strpbrk()

Synopsis

char * strpbrk(
   const char * str,
   const char * accept)

Function

Locate the first occurrence of any character in accept in str.

Inputs

str - Search this string
accept - Look for these characters

Result

A pointer to the first occurrence of any character in accept in str
or NULL if no character of accept is not found in str.

Example

char buffer[64];

strcpy (buffer, "Hello ");

// This returns a pointer to the first l in buffer.
strpbrk (buffer, "lo");

// This returns NULL
strpbrk (buffer, "xyz");

strrchr()

Synopsis

char * strrchr(
   const char * str,
   int          c)

Function

Searches for the last character c in a string.

Inputs

str - Search this string
c - Look for this character

Result

A pointer to the first occurrence of c in str or NULL if c is not
found in str.

Example

char buffer[64];

strcpy (buffer, "Hello ");

// This returns a pointer to the second l in buffer.
strrchr (buffer, 'l');

// This returns NULL
strrchr (buffer, 'x');

strrev()

Synopsis

char * strrev(
   char       * s)

Function

Reverse a string (rotate it about its midpoint)

Inputs

s - The string to be reversed

Result

The original string pointer

Example

char buffer[64];

strcpy (buffer, "Hello);
strrev(buffer);

// buffer now contains "olleH"

Notes

SAS C specific

strsep()

Synopsis

char * strsep(
   char       ** strptr,
   const char * sep)

Function

Separates a string by the characters in sep.

Inputs

str - The string to check or NULL if the next word in
        the last string is to be searched.
sep - Characters which separate "words" in str.

Result

The first word in str or the next one if str is NULL.

Example

char buffer[64];
char **bufptr

strcpy (buffer, "Hello, this is a test.");
*bufptr = buffer

// First word. Returns "Hello"
strtok (bufptr, " \t,.");

// Next word. Returns "this"
strtok (bufptr, " \t,.");

// Next word. Returns "is"
strtok (bufptr, " \t");

// Next word. Returns "a"
strtok (bufptr, " \t");

// Next word. Returns "test."
strtok (bufptr, " \t");

// Next word. Returns NULL.
strtok (bufptr, " \t");

Notes

The function changes str !

strspn()

Synopsis

size_t strspn(
   const char * str,
   const char * accept)

Function

Calculates the length of the initial segment of str which consists
entirely of characters in accept.

Inputs

str - The string to check.
accept - Characters which have to be in str.

Result

Length of the initial segment of str which contains only
characters from accept.

Example

char buffer[64];

strcpy (buffer, "Hello ");

// Returns 5
strspn (buffer, "Helo");

// Returns 0
strspn (buffer, "xyz");

strstr()

Synopsis

char * strstr(
   const char * str,
   const char * search)

Function

Searches for a string in a string.

Inputs

str - Search this string
search - Look for this string

Result

A pointer to the first occurrence of search in str or NULL if search
is not found in str.

Example

char buffer[64];

strcpy (buffer, "Hello ");

// This returns a pointer to the first l in buffer.
strstr (buffer, "llo ");

// This returns NULL
strstr (buffer, "llox");

strtod()

Synopsis

double strtod(
   const char * str,
   char      ** endptr)

Function

Convert a string of digits into a double.

Inputs

str - The string which should be converted. Leading
        whitespace are ignored. The number may be prefixed
        by a '+' or '-'. An 'e' or 'E' introduces the exponent.
        Komma is only allowed before exponent.
endptr - If this is non-NULL, then the address of the first
        character after the number in the string is stored
        here.

Result

The value of the string. The first character after the number
is returned in *endptr, if endptr is non-NULL. If no digits can
be converted, *endptr contains str (if non-NULL) and 0 is
returned.

Bugs

NAN is not handled at the moment

strtof()

Synopsis

float strtof(
   const char * str,
   char      ** endptr)

Function

Convert a floating-point number from an ASCII decimal
representation into a double-precision format.

Inputs

str - The string which should be converted. Leading
        whitespace are ignored.
endptr - If this is non-NULL, then the address of the first
        character after the number in the string is stored
        here.

Result

The float value of the string. The first character after the number
is returned in *endptr, if endptr is non-NULL. If no digits can
be converted, *endptr contains str (if non-NULL) and 0 is
returned.

strtoimax()

Synopsis

intmax_t strtoimax(
   const char * nptr,
   char      ** endptr,
   int          base)

Function

Convert a string of digits into an integer according to the
given base. This function is like strtol() except the fact,
that it returns a value of type intmax_t.

Inputs

str - The string which should be converted.
endptr - If this is non-NULL, then the address of the first
        character after the number in the string is stored
        here.
base - The base for the number.

Result

The value of the string. The first character after the number
is returned in *endptr, if endptr is non-NULL. If no digits can
be converted, *endptr contains str (if non-NULL) and 0 is
returned.

Bugs

errno is not set as required by C99 standard

strtok()

Synopsis

char * strtok(
   char       * str,
   const char * sep)

Function

Separates a string by the characters in sep.

Inputs

str - The string to check or NULL if the next word in
        the last string is to be searched.
sep - Characters which separate "words" in str.

Result

The first word in str or the next one if str is NULL.

Example

char buffer[64];

strcpy (buffer, "Hello, this is a test.");

// Init. Returns "Hello"
strtok (str, " \t,.");

// Next word. Returns "this"
strtok (NULL, " \t,.");

// Next word. Returns "is"
strtok (NULL, " \t");

// Next word. Returns "a"
strtok (NULL, " \t");

// Next word. Returns "test."
strtok (NULL, " \t");

// Next word. Returns NULL.
strtok (NULL, " \t");

Notes

The function changes str !

strtok_r()

Synopsis

char * strtok_r(
   char       * str,
   const char * sep,
   char **saveptr)

Function

Separates a string by the characters in sep.

Inputs

str - The string to check or NULL if the next word in
        the last string is to be searched.
sep - Characters which separate "words" in str.
saveptr - internal context for next scan

Result

The first word in str or the next one if str is NULL.

Example

char buffer[64];
char *ptr;

strcpy (buffer, "Hello, this is a test.");

// Init. Returns "Hello"
strtok_r (str, " \t,.", &ptr);

// Next word. Returns "this"
strtok_r (NULL, " \t,.", &ptr);

// Next word. Returns "is"
strtok_r (NULL, " \t", &ptr);

// Next word. Returns "a"
strtok_r (NULL, " \t", &ptr);

// Next word. Returns "test."
strtok_r (NULL, " \t", &ptr);

// Next word. Returns NULL.
strtok_r (NULL, " \t", &ptr);

Notes

The function changes str !

strtol()

Synopsis

long strtol(
   const char * str,
   char      ** endptr,
   int          base)

Function

Convert a string of digits into an integer according to the
given base.

Inputs

str - The string which should be converted. Leading
        whitespace are ignored. The number may be prefixed
        by a '+' or '-'. If base is above 10, then the
        alphabetic characters from 'A' are used to specify
        digits above 9 (ie. 'A' or 'a' is 10, 'B' or 'b' is
        11 and so on until 'Z' or 'z' is 35).
endptr - If this is non-NULL, then the address of the first
        character after the number in the string is stored
        here.
base - The base for the number. May be 0 or between 2 and 36,
        including both. 0 means to autodetect the base. strtoul()
        selects the base by inspecting the first characters
        of the string. If they are "0x", then base 16 is
        assumed. If they are "0", then base 8 is assumed. Any
        other digit will assume base 10. This is like in C.

        If you give base 16, then an optional "0x" may
        precede the number in the string.

Result

The value of the string. The first character after the number
is returned in *endptr, if endptr is non-NULL. If no digits can
be converted, *endptr contains str (if non-NULL) and 0 is
returned.

Example

// returns 1, ptr points to the 0-Byte
strol ("  \t +0x1", &ptr, 0);

// Returns 15. ptr points to the a
strol ("017a", &ptr, 0);

// Returns 215 (5*36 + 35)
strol ("5z", &ptr, 36);

strtold()

Synopsis

long double strtold(
   const char * str,
   char      ** endptr)

Function

Convert a string of digits into a long double.

Inputs

str - The string which should be converted. Leading
        whitespace are ignored. The number may be prefixed
        by a '+' or '-'. An 'e' or 'E' introduces the exponent.
        Comma is only allowed before exponent.
endptr - If this is non-NULL, then the address of the first
        character after the number in the string is stored
        here.

Result

The value of the string. The first character after the number
is returned in *endptr, if endptr is non-NULL. If no digits can
be converted, *endptr contains str (if non-NULL) and 0 is
returned.

Notes

We make the compiler do an internal conversion from a double
to a long double. Because of this we lose a some precision, but for
now it works.

Bugs

NAN is not handled at the moment

strtoll()

Synopsis

long long strtoll(
   const char * restrict   str,
   char      ** restrict   endptr,
   int                     base)

Function

Convert a string of digits into an integer according to the
given base.

Inputs

str - The string which should be converted. Leading
        whitespace are ignored. The number may be prefixed
        by a '+' or '-'. If base is above 10, then the
        alphabetic characters from 'A' are used to specify
        digits above 9 (ie. 'A' or 'a' is 10, 'B' or 'b' is
        11 and so on until 'Z' or 'z' is 35).
endptr - If this is non-NULL, then the address of the first
        character after the number in the string is stored
        here.
base - The base for the number. May be 0 or between 2 and 36,
        including both. 0 means to autodetect the base. strtoul()
        selects the base by inspecting the first characters
        of the string. If they are "0x", then base 16 is
        assumed. If they are "0", then base 8 is assumed. Any
        other digit will assume base 10. This is like in C.

        If you give base 16, then an optional "0x" may
        precede the number in the string.

Result

The value of the string. The first character after the number
is returned in *endptr, if endptr is non-NULL. If no digits can
be converted, *endptr contains str (if non-NULL) and 0 is
returned.

Example

// returns 1, ptr points to the 0-Byte
strtoll ("  \t +0x1", &ptr, 0);

// Returns 15. ptr points to the a
strtoll ("017a", &ptr, 0);

// Returns 215 (5*36 + 35)
strtoll ("5z", &ptr, 36);

strtoul()

Synopsis

unsigned long strtoul(
   const char * str,
   char      ** endptr,
   int          base)

Function

Convert a string of digits into an integer according to the
given base.

Inputs

str - The string which should be converted. Leading
        whitespace are ignored. The number may be prefixed
        by a '+' or '-'. If base is above 10, then the
        alphabetic characters from 'A' are used to specify
        digits above 9 (ie. 'A' or 'a' is 10, 'B' or 'b' is
        11 and so on until 'Z' or 'z' is 35).
endptr - If this is non-NULL, then the address of the first
        character after the number in the string is stored
        here.
base - The base for the number. May be 0 or between 2 and 36,
        including both. 0 means to autodetect the base. strtoul()
        selects the base by inspecting the first characters
        of the string. If they are "0x", then base 16 is
        assumed. If they are "0", then base 8 is assumed. Any
        other digit will assume base 10. This is like in C.

        If you give base 16, then an optional "0x" may
        precede the number in the string.

Result

The value of the string. The first character after the number
is returned in *endptr, if endptr is non-NULL. If no digits can
be converted, *endptr contains str (if non-NULL) and 0 is
returned.

Example

// Returns 1, ptr points to the 0-Byte
strtoul ("  \t +0x1", &ptr, 0);

// Returns 15. ptr points to the a
strtoul ("017a", &ptr, 0);

// Returns 215 (5*36 + 35)
strtoul ("5z", &ptr, 36);

strtoull()

Synopsis

unsigned long long strtoull(
   const char * restrict   str,
   char      ** restrict   endptr,
   int                     base)

Function

Convert a string of digits into an integer according to the
given base.

Inputs

str - The string which should be converted. Leading
        whitespace are ignored. The number may be prefixed
        by a '+' or '-'. If base is above 10, then the
        alphabetic characters from 'A' are used to specify
        digits above 9 (ie. 'A' or 'a' is 10, 'B' or 'b' is
        11 and so on until 'Z' or 'z' is 35).
endptr - If this is non-NULL, then the address of the first
        character after the number in the string is stored
        here.
base - The base for the number. May be 0 or between 2 and 36,
        including both. 0 means to autodetect the base. strtoull()
        selects the base by inspecting the first characters
        of the string. If they are "0x", then base 16 is
        assumed. If they are "0", then base 8 is assumed. Any
        other digit will assume base 10. This is like in C.

        If you give base 16, then an optional "0x" may
        precede the number in the string.

Result

The value of the string. The first character after the number
is returned in *endptr, if endptr is non-NULL. If no digits can
be converted, *endptr contains str (if non-NULL) and 0 is
returned.

Example

// Returns 1, ptr points to the 0-Byte
strtoull ("  \t +0x1", &ptr, 0);

// Returns 15. ptr points to the a
strtoull ("017a", &ptr, 0);

// Returns 215 (5*36 + 35)
strtoull ("5z", &ptr, 36);

strtoumax()

Synopsis

uintmax_t strtoumax(
   const char * nptr,
   char      ** endptr,
   int          base)

Function

Convert a string of digits into an integer according to the
given base. This function is like strtoul() except the fact,
that it returns a value of type uintmax_t.

Inputs

str - The string which should be converted.
endptr - If this is non-NULL, then the address of the first
        character after the number in the string is stored
        here.
base - The base for the number.

Result

The value of the string. The first character after the number
is returned in *endptr, if endptr is non-NULL. If no digits can
be converted, *endptr contains str (if non-NULL) and 0 is
returned.

Bugs

errno is not set as required by C99 standard

strupr()

Synopsis

char * strupr(
   char * str)

Function

Converts a string to all upper case characters. Modifies
the given string.

Inputs

str - The string to convert.

Result

The same string buffer is passed back with all characters converted.

strxfrm()

Synopsis

size_t strxfrm(
   char * restrict dst,
   const char * restrict src,
   size_t n)

Function

The strxfrm() function transforms a null-terminated string pointed to by
src according to the current locale collation if any, then copies the
transformed string into dst.  Not more than n characters are copied into
dst, including the terminating null character added.  If n is set to 0
(it helps to determine an actual size needed for transformation), dst is
permitted to be a NULL pointer.

Comparing two strings using strcmp() after strxfrm() is equal to compar-
ing two original strings with strcoll().

Inputs

dst - the destination string's buffer
src - the source string
n   - the size of the dst buffer.

Result

Upon successful completion, strxfrm() returns the length of the trans-
formed string not including the terminating null character.  If this
value is n or more, the contents of dst are indeterminate.

Notes

stdc.library only support "C" locale so strxfrm is equivalent to
strncpy.

system()

Synopsis

int system(
   const char *string)

Function

Execute a command string. If string is NULL then 1 will be returned.

Inputs

string - command to execute or NULL

Result

Return value of command executed. If value < 0 errno indicates error.
1 is return if string is NULL.

Notes

The system() version of stdcio.library just passes the command
to SystemTags() dos.library call.

time()

Synopsis

time_t time(
   time_t * tloc)

Function

time() returns the time since 00:00:00 GMT, January 1, 1970,
measured in seconds.

Inputs

tloc - If this pointer is non-NULL, then the time is written into
        this variable as well.

Result

The number of seconds.

Example

time_t tt1, tt2;

// tt1 and tt2 are the same
tt1 = time (&tt2);

// This is valid, too
tt1 = time (NULL);

Notes

This function must not be used in a shared library or
in a threaded application.

tmpfile()

Synopsis

FILE * tmpfile(
   void)

Function

The tmpfile() function creates a temporary file that is different from
any other existing file and that will automatically be removed when
it is closed or at program termination. The file is opened for update
with "wb+" mode.

Result

Pointer to the stream that was created. On error NULL is returned.

Example

#include <errno.h>
#include <stdio.h>
#include <string.h>

main()
{
  FILE * fp;

  fp = tmpfile();
  if ( fp == NULL)
  {
    perror(strerror(errno));
    return;
  }

  fprintf(fp, "do a bit of writing to the temp file");
}

Notes

This function uses tmpnam(NULL) to get the file name.

tmpnam()

Synopsis

char *tmpnam(
   char *s)

Function

The tmpnam function generates a string that is a valid file name and
that is not the same as the name of an existing file. The function
is potentially capable of generating TMP_MAX different strings, but
any or all of them may already be in use by existing files and thus
not be suitable return values.

Inputs

Pointer to a string of at least L_tmpnam characters.

Result

The resulting file name is returned in the input string pointer
or a pointer to an internal buffer if NULL was passed to the function.
If file name generation failed a NULL is returned.

ungetc()

Synopsis

int ungetc(
   int    c,
   FILE * stream)

Function

Puch the character c character back into the stream.

Inputs

c - Put this character back into the stream. The next read will
        return this character. If you push back more than one
        character, then they will be returned in reverse order.
        The function guarantees that one character can be
        pushed back but no more. It is possible to push the EOF
        character back into the stream.
stream - Read from this stream

Result

c or EOF on error.

vasprintf()

Synopsis

int vasprintf(
   char **restrict str, const char *restrict format, va_list args)

Function

Analog of vsprintf, except that sotrage is allocated for a string
large enough to hold the output including the terminating null
byte

Inputs

str - Where to store the pointer for the allocated string.
format - A printf() format string.
args - A list of arguments for the format string.

Result

The number of characters written, or EOF on error.

vfprintf()

Synopsis

int vfprintf(
   FILE       * restrict stream,
   const char * restrict format,
   va_list      args)

Function

Format a list of arguments and print them on the specified stream.

Inputs

stream - A stream on which one can write
format - A printf() format string.
args - A list of arguments for the format string.

Result

The number of characters written.

vfscanf()

Synopsis

int vfscanf(
   FILE       * stream,
   const char * format,
   va_list      args)

Function

Read the scream, scan it as the format specified and write the
result of the conversion into the specified arguments.

Inputs

stream - A stream to read from
format - A scanf() format string.
args - A list of arguments for the results.

Result

The number of converted arguments.

vprintf()

Synopsis

int vprintf(
   const char * format,
   va_list      args)

Function

Format a list of arguments and print them on the standard output.

Inputs

format - A printf() format string.
args - A list of arguments for the format string.

Result

The number of characters written.

vscanf()

Synopsis

int vscanf(
   const char * format,
   va_list      args)

Function

Scan the standard input and convert it into the arguments as
specified by format.

Inputs

format - A scanf() format string.
args - A list of arguments for the results

Result

The number of converted parameters.

vsnprintf()

Synopsis

int vsnprintf(
   char        * str,
   size_t      n,
   const char * format,
   va_list      args)

Function

Format a list of arguments and put them into the string str.
The function makes sure that no more than n characters (including
the terminal 0 byte) are written into str.
If n is zero, nothing is written, and s may be a null pointer. Otherwise,
output characters beyond the n-1st are discarded rather than being written
to the array, and a null character is written at the end of the characters
actually written into the array. If copying takes place between objects
that overlap, the behavior is undefined.

Inputs

str - The formatted result is stored here
n - The size of str
format - A printf() format string.
args - A list of arguments for the format string.

Result

Function returns the number of characters that would have been
written had n been sufficiently large, not counting the terminating null
character, or a negative value if an encoding error occurred. Thus, the
null-terminated output has been completely written if and only if the
returned value is nonnegative and less than n.

vsprintf()

Synopsis

int vsprintf(
   char       * str,
   const char * format,
   va_list      args)

Function

Format a list of arguments and put them into the string str.

Inputs

str - The formatted result is stored here
format - A printf() format string.
args - A list of arguments for the format string.

Result

The number of characters written.

Notes

No check is made that str is large enough to contain the result.

vsscanf()

Synopsis

int vsscanf(
   const char *str,
   const char *format,
   va_list     args)

Function

Scan a string and convert it into the arguments as specified
by format.

Inputs

str - Scan this string
format - A scanf() format string.
args - A list of arguments for the results

Result

The number of arguments converted.

wcscat()

Synopsis

wchar_t *wcscat(
   wchar_t *wcdst,
   const wchar_t *wcsrc)

Function

Appends a wide string, onto another wide string.

Inputs

wcdst - the wide string that will have the text appended to it.
wcsrc - the wide string to append.

Result

A pointer to the resulting wide string.

wcscmp()

Synopsis

int wcscmp(
   const wchar_t *wcstra,
   const wchar_t *wcstrb)

Function

Lexicographically compares two null-terminated wide strings.

Inputs

wcstra - wide string to compare.
wcstrb - wide string to compare.

Result

If wcstra appears before wcstrb lexographically, then -1 is returned.
If wcstrb appears before wcstra lexographically, then 1 is returned.
If the strings are equal, 0 is returned.

wcscpy()

Synopsis

wchar_t *wcscpy(
   wchar_t *wcdst,
   const wchar_t *wcsrc)

Function

Copies a wide string, to another wide string.

Inputs

wcdst - the wide string that will be copied to.
wcsrc - the wide string to copy.

Result

A pointer to the resulting wide string.

wcslen()

Synopsis

size_t wcslen(
   const wchar_t *wcstr)

Function

Returns the length of a wide string.

Inputs

wcstr - wide string to tally.

Result

The number of non-null wide characters, in the wide string.

wcsncmp()

Synopsis

int wcsncmp(
   const wchar_t *wcstra,
   const wchar_t *wcstrb,
   size_t cnt)

Function

Lexicographically compares two null-terminated wide strings, upto the
specified length

Inputs

wcstra - wide string to compare.
wcstrb - wide string to compare.
cnt - maximum number of wide characters to compare.

wcsncpy()

Synopsis

wchar_t *wcsncpy(
   wchar_t *wcdst,
   const wchar_t *wcsrc,
   size_t cnt)

Function

Copies upto the specified length of wide characters from
a wide string, to another wide string.

Inputs

wcdst - the wide string that will be copied to.
wcsrc - the wide string to copy.
cnt - maximum number of wide characters to copy.

Result

A pointer to the resulting wide string.

wcstombs()

Synopsis

size_t wcstombs(
   char * restrict s,
   const wchar_t * restrict pwcs,
   size_t n)

Function

C99 function wcstombs

Notes

stdc.library currently only implements "C" locale

wctomb()

Synopsis

int wctomb(
   char *s,
   wchar_t wchar)

Function

Converts one wide char to a multi-byte char.

Inputs

wchar: wide char to convert
s: string pointer to put the converted char into.

Result

If s is not NULL it returns the number of chars written into s;
zero is returned when wchar is a NULL character; -1 when the character
is not valid.
If s is NULL the function returns zero or non-zero when multi-byte
string resp don't or do have state-dependent encodings.

Notes

stdc.library currently only implements "C" locale.
This means that 0 is returned when s is NULL and 0, 1 or -1 when s is
not NULL.

Docutils System Messages

System Message: ERROR/3 (/home/vsts/work/1/b/documentation/web/documentation/developers/autodocs/stdc.en, line 773); backlink

Unknown target name: "__stdcio_getenv()".

System Message: ERROR/3 (/home/vsts/work/1/b/documentation/web/documentation/developers/autodocs/stdc.en, line 773); backlink

Unknown target name: "setenv()".

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