[Last modified : 2003.07.09]
<assert.h>
: Diagnostics <ctype.h>
: Character Class Tests <errno.h>
: Error Codes Reported by (Some) Library Functions <float.h>
: Implementation-defined Floating-Point Limits <limits.h>
: Implementation-defined Limits <locale.h>
: Locale-specific Information <math.h>
: Mathematical Functions <setjmp.h>
: Non-local Jumps <signal.h>
: Signals <stdarg.h>
: Variable Argument Lists <stddef.h>
: Definitions of General Use <stdio.h>
: Input and Output <stdlib.h>
: Utility functions <string.h>
: String functions <time.h>
: Time and Date functions void assert(int expression); NDEBUG
is defined where <assert.h> is included.) If expression
equals zero, message printed on stderr
and abort
called to terminate execution. Source filename and line number in
message are from preprocessor macros __FILE__ and __LINE__.
[Contents]
int isalnum(int c); isalpha(c) or isdigit(c)
int isalpha(int c); isupper(c) or islower(c)
int iscntrl(int c); 0x00
(NUL) to 0x1F (US), and 0x7F
(DEL) int isdigit(int c); int isgraph(int c); int islower(int c); int isprint(int c); 0x20 (' ') to 0x7E
('~') int ispunct(int c); int isspace(int c); int isupper(int c); int isxdigit(int c); int tolower(int c); int toupper(int c); [Contents]
errno EDOM ERANGE Notes:
[Contents]
FLT_RADIX FLT_ROUNDS Where the prefix "FLT" pertains to type float,
"DBL" to type double, and "LDBL"
to type long double:
FLT_DIG DBL_DIG LDBL_DIG FLT_EPSILON DBL_EPSILON LDBL_EPSILON 1.0 + x
!= 1.0 FLT_MANT_DIG DBL_MANT_DIG LDBL_MANT_DIG FLT_RADIX,
in mantissa FLT_MAX DBL_MAX LDBL_MAX FLT_MAX_EXP DBL_MAX_EXP LDBL_MAX_EXP FLT_RADIX
can be raised and remain representable FLT_MIN DBL_MIN LDBL_MIN FLT_MIN_EXP DBL_MIN_EXP LDBL_MIN_EXP FLT_RADIX
can be raised and remain representable [Contents]
CHAR_BIT char CHAR_MAX char CHAR_MIN char SCHAR_MAX signed char SCHAR_MIN signed char UCHAR_MAX unsigned char SHRT_MAX short SHRT_MIN short USHRT_MAX unsigned short INT_MAX int INT_MIN int UINT_MAX unsigned int LONG_MAX long LONG_MIN long ULONG_MAX unsigned long [Contents]
struct lconv char* decimal_point;
char* grouping; char* thousands_sep; char* currency_symbol; char* int_curr_symbol; char* mon_decimal_point; char* mon_grouping; char* mon_thousands_sep; char* negative_sign; char* positive_sign; char frac_digits; char int_frac_digits; char n_cs_precedes; 1) or follows (0)
negative monetary values char n_sep_by_space; 1) or is not (0)
separated by space from negative monetary values char n_sign_posn; 0 1 2 3 4 char p_cs_precedes; 1) or follows (0)
positive monetary values char p_sep_by_space; 1) or is not (0)
separated by space from non-negative monetary values char p_sign_posn; n_sign_posn decimal_point.
struct
lconv* localeconv(void); char* setlocale(int category,
const char* locale); category
and locale. Returns string describing new
locale or null on error. (Implementations are permitted to define
values of category
additional to those describe here.) LC_ALL category
argument for all categories LC_NUMERIC category
for numeric formatting information LC_MONETARY category
for monetary formatting information LC_COLLATE category
for information affecting collating functions LC_CTYPE category
for information affecting character
class tests functions LC_TIME category
for information affecting time conversions functions NULL [Contents]
On domain error, implementation-defined value returned and errno
set to EDOM.
On range error, errno
set to ERANGE
and return value is HUGE_VAL
with correct sign for overflow, or zero for underflow. Angles are in
radians.
HUGE_VAL double exp(double x); x double log(double x); x double log10(double x); x double pow(double x, double y);
x raised to power y
double sqrt(double x); x double ceil(double x); x double floor(double x); x double fabs(double x); x double ldexp(double x, int n);
x times 2 to the power n
double frexp(double x, int* exp);
x non-zero, returns value, with
absolute value in interval [1/2, 1), and assigns to *exp
integer such that product of return value and 2 raised to the power *exp
equals x; if x zero,
both return value and *exp are zero double modf(double x, double* ip);
*ip
integral part of x, both with same sign as x
double fmod(double x, double y);
y non-zero, floating-point remainder
of x/y, with same sign as x;
if y zero, result is implementation-defined double sin(double x); x double cos(double x); x double tan(double x); x double asin(double x); x double acos(double x); x double atan(double x); x double atan2(double y, double x);
y/x double sinh(double x); x double cosh(double x); x double tanh(double x); x [Contents]
jmp_buf int setjmp(jmp_buf env);
env and
returns zero. Subsequent call to longjmp
with same env returns non-zero. void longjmp(jmp_buf env,
int val); setjmp
with specified env. Execution resumes as a
second return from setjmp,
with returned value val if specified value
non-zero, or 1 otherwise. [Contents]
SIGABRT SIGFPE SIGILL SIGINT SIGSEGV SIGTERM SIG_DFL SIG_ERR signal
return value indicating error SIG_IGN void (*signal(int sig,
void (*handler)(int)))(int); handler
is SIG_DFL,
implementation-defined default behaviour will be used; if SIG_IGN,
signal will be ignored; otherwise function pointed to by handler
will be invoked with argument sig. In the last case,
handling is restored to default behaviour before handler
is called. If handler returns, execution
resumes where signal occurred. signal
returns the previous handler or SIG_ERR on error. Initial
state is implementation-defined. Implementations may may define signals
additional to those listed here. int raise(int sig); sig. Returns zero on
success. [Contents]
va_list void va_start(va_list
ap, lastarg); ap.
lastarg is the last named parameter of the
function. type va_arg(va_list ap, type); type) and value
of the next unnamed argument. void va_end(va_list
ap); [Contents]
NULL offsetof(stype, m) m from start
of structure type stype. ptrdiff_t size_t sizeof
operator. [Contents]
BUFSIZ setbuf.
EOF FILENAME_MAX FOPEN_MAX L_tmpnam tmpnam. NULL SEEK_CUR origin argument to fseek
specifying current file position. SEEK_END origin argument to fseek
specifying end of file. SEEK_SET origin argument to fseek
specifying beginning of file. TMP_MAX tmpnam. _IOFBF mode argument to setvbuf
specifying full buffering. _IOFBF mode argument to setvbuf
specifying line buffering. _IOFBF mode argument to setvbuf
specifying no buffering. stdin stdout stderr FILE fpos_t size_t sizeof
operator. FILE* fopen(const
char* filename, const
char* mode); filename and returns a
stream, or NULL
on failure. mode may be one of the following
for text files:
"r" "w" "a" "r+" "w+" "a+" b included (after the first
character), for binary files. FILE*
freopen(const char* filename, const char* mode,
FILE* stream); stream, then
opens file filename with specified mode and
associates it with stream. Returns stream
or NULL
on error. int fflush(FILE* stream);
stream and returns zero
on success or EOF
on error. Effect undefined for input stream. fflush(NULL)
flushes all output streams. int fclose(FILE* stream);
EOF
on error, zero otherwise. int remove(const char* filename);
int rename(const char* oldname,
const char* newname); oldname to newname.
Returns non-zero on failure. FILE* tmpfile();
"wb+") which will be
removed when closed or on normal program termination. Returns stream or
NULL
on failure. char* tmpname(char s[L_tmpnam]); s (if s
non-null) and returns unique name for a temporary file. Unique name is
returned for each of the first TMP_MAX
invocations. int setvbuf(FILE*
stream, char* buf, int mode, size_t size); stream. mode
is _IOFBF
for full buffering, _IOLBF
for line buffering, _IONBF
for no buffering. Non-null buf specifies
buffer of size size to be used; otherwise, a
buffer is allocated. Returns non-zero on error. Call must be before any
other operation on stream. void setbuf(FILE*
stream, char* buf); buf,
turns off buffering, otherwise equivalent to (void)setvbuf(stream, buf, _IOFBF, BUFSIZ). int fprintf(FILE*
stream, const char* format, ...); format)
and writes output to stream stream. Number of
characters written, or negative value on error, is returned. Conversion
specifications consist of:
% - + 0 # o,
first digit will be zero, for [xX], prefix 0x
or 0X to non-zero value, for [eEfgG], always
decimal point, for [gG] trailing zeros not removed. *,
value taken from next argument (which must be int). . (separating width from precision):
s,
maximum characters to be printed from the string, for [eEf],
digits after decimal point, for [gG], significant digits,
for an integer, minimum number of digits to be printed. If specified as
*, value taken from next argument (which must be int).
h short or unsigned short l long or unsigned long L long double d,i int argument, printed in signed decimal
notation o int argument, printed in unsigned octal
notation x,X int argument, printed in unsigned
hexadecimal notation u int argument, printed in unsigned decimal
notation c int argument, printed as single character s char* argument f double argument, printed with format [-]mmm.ddd
e,E double argument, printed with format [-]m.dddddd(e|E)(+|-)xx
g,G double argument p void* argument, printed as pointer n int* argument : the number of characters
written to this point is written into argument % int printf(const char* format,
...); printf(f,
...) is equivalent to fprintf(stdout,
f, ...) int sprintf(char* s,
const char* format, ...); s, which must
be large enough to hold the output, rather than to a stream.
Output is NUL-terminated. Returns length (excluding the
terminating NUL). int vfprintf(FILE*
stream, const char* format, va_list arg); fprintf
with variable argument list replaced by arg,
which must have been initialised by the va_start
macro (and may have been used in calls to va_arg).
int vprintf(const char* format,
va_list arg); printf
with variable argument list replaced by arg,
which must have been initialised by the va_start
macro (and may have been used in calls to va_arg).
int vsprintf(char* s, const char* format,
va_list arg); sprintf
with variable argument list replaced by arg,
which must have been initialised by the va_start
macro (and may have been used in calls to va_arg).
int fscanf(FILE* stream,
const char* format, ...); stream
according to format format. The function
returns when format is fully processed.
Returns number of items converted and assigned, or EOF
if end-of-file or error occurs before any conversion. Each of the
arguments following format must be a
pointer. Format string may contain:
% *"
h short rather
than int l long rather than
int, or double rather than float
L long double
rather than float d int* parameter
required i int* parameter required;
decimal, octal or hex o int* parameter required u unsigned int*
parameter required x int* parameter
required c char* parameter required;
white-space is not skipped, and NUL-termination is not
performed s char*
parameter required; string is NUL-terminated e,f,g float* parameter
required p void* parameter required
n int* parameter
required [...] char*
parameter required; string is NUL-terminated [^...] char*
parameter required; string is NUL-terminated % %; no assignment int scanf(const char* format,
...); scanf(f,
...) is equivalent to fscanf(stdin,
f, ...) int sscanf(char* s, const char* format,
...); fscanf,
but input read from string s. int fgetc(FILE* stream);
stream,
or EOF
on end-of-file or error. char* fgets(char* s, int n,
FILE* stream); stream
to s, stopping when n-1
characters copied, newline copied, end-of-file reached or error occurs.
If no error, s is NUL-terminated.
Returns NULL
on end-of-file or error, s otherwise. fputc(int c, FILE* stream); c, to stream stream.
Returns c, or EOF
on error. char* fputs(const char* s,
FILE* stream); s, to (output) stream stream.
Returns non-negative on success or EOF
on error. int getc(FILE* stream);
fgetc
except that it may be a macro. int getchar(void); getc(stdin).
char* gets(char* s);
stdin
into s until newline encountered, end-of-file
reached, or error occurs. Does not copy newline. NUL-terminates
s. Returns s, or NULL
on end-of-file or error. Should not be used because of the
potential for buffer overflow. int putc(int c, FILE* stream); fputc
except that it may be a macro. int putchar(int c);
putchar(c) is equivalent to putc(c, stdout).
int puts(const char* s);
s (excluding terminating NUL)
and a newline to stdout.
Returns non-negative on success, EOF
on error. int ungetc(int c, FILE* stream); c (which must not be EOF),
onto (input) stream stream such that it will
be returned by the next read. Only one character of pushback is
guaranteed (for each stream). Returns c, or EOF
on error. size_t fread(void*
ptr, size_t size,
size_t nobj, FILE* stream); nobj objects of size size
from stream stream into ptr
and returns number of objects read. (feof
and ferror
can be used to check status.) size_t fwrite(const void* ptr,
size_t size, size_t nobj, FILE*
stream); stream, nobj
objects of size size from array ptr.
Returns number of objects written. int fseek(FILE* stream,
long offset, int origin); stream and
clears end-of-file indicator. For a binary stream, file position is set
to offset bytes from the position indicated by
origin: beginning of file for SEEK_SET,
current position for SEEK_CUR,
or end of file for SEEK_END.
Behaviour is similar for a text stream, but offset
must be zero or, for SEEK_SET
only, a value returned by ftell.
Returns non-zero on error. long ftell(FILE* stream);
stream,
or -1 on error. void rewind(FILE*
stream); fseek(stream,
0L, SEEK_SET); clearerr(stream).
int fgetpos(FILE*
stream, fpos_t* ptr);
stream
in *ptr. Returns non-zero on error. int fsetpos(FILE*
stream, const fpos_t* ptr);
*ptr.
Returns non-zero on error. void clearerr(FILE*
stream); stream.
int feof(FILE* stream);
stream.
int ferror(FILE* stream);
stream.
void perror(const char* s);
s (if non-null) and strerror(errno)
to standard error as would:
fprintf(stderr, "%s: %s\n", (s != NULL ? s : ""), strerror(errno))
[Contents]
EXIT_FAILURE status argument to exit
indicating failure. EXIT_SUCCESS status argument to exit
indicating success. RAND_MAX rand().
NULL div_t div().
Structure having members:
int quot; int rem; ldiv_t ldiv().
Structure having members:
long quot; long rem; size_t sizeof
operator. int abs(int n); long labs(long n); n. div_t div(int num,
int denom); ldiv_t ldiv(long num,
long denom); num/denom.
double atof(const char* s); strtod(s,
(char**)NULL)
except that errno
is not necessarily set on conversion error. int atoi(const char* s); (int)strtol(s,
(char**)NULL,
10) except that errno
is not necessarily set on conversion error. long atol(const char* s); strtol(s,
(char**)NULL,
10) except that errno
is not necessarily set on conversion error. double strtod(const char* s,
char** endp); s
to type double. If endp
non-null, stores pointer to unconverted suffix in *endp.
On overflow, sets errno
to ERANGE
and returns HUGE_VAL
with the appropriate sign; on underflow, sets errno
to ERANGE
and returns zero; otherwise returns converted value. long strtol(const char* s,
char** endp, int base); s
to type long. If endp non-nu ll,
stores pointer to unconverted suffix in *endp.
If base between 2 and 36, that base used for
conversion; if zero, leading (after any sign) 0X or 0x
implies hexadecimal, leading 0 (after any sign) implies
octal, otherwise decimal assumed. Leading 0X or 0x
permitted for base hexadecimal. On overflow, sets errno
to ERANGE
and returns LONG_MAX
or LONG_MIN
(as appropriate for sign); otherwise returns converted value. unsigned long strtoul(const char* s,
char** endp, int base); strtol
except result is unsigned long and value on overflow is ULONG_MAX. void* calloc(size_t nobj,
size_t size); nobj objects each of
size size, or NULL
on error. void* malloc(size_t size);
NULL
on error. void* realloc(void* p, size_t size);
size,
initialised, to minimum of old and new sizes, to existing contents of p
(if non-null), or NULL
on error. On success, old object deallocated, otherwise unchanged. void free(void* p); p non-null, deallocates space to
which it points. void abort(); raise(SIGABRT). void exit(int status);
atexit
are called (in reverse order to that in which installed), open files
are flushed, open streams are closed and control is returned to
environment. status is returned to environment
in implementation-dependent manner. Zero or EXIT_SUCCESS
indicates successful termination and EXIT_FAILURE
indicates unsuccessful termination. Implementations may define other
values. int atexit(void (*fcm)(void));
fcn to be called when program
terminates normally (or when main returns). Returns
non-zero on failure. int system(const char* s); s is not NULL,
passes s to environment for execution, and
returns status reported by command processor; if s
is NULL,
non-zero returned if environment has a command processor. char* getenv(const char* name); name
from implementation's environment, or NULL
if no such string exists. void* bsearch(const void* key, const void* base,
size_t n, size_t size, int (*cmp)(const
void* keyval, const
void* datum)); base (of n
objects each of size size) for item matching key
according to comparison function cmp. cmp
must return negative value if first argument is less than second, zero
if equal and positive if greater. Items of base
are assumed to be in ascending order (according to cmp).
Returns a pointer to an item matching key, or NULL
if none found. void qsort(void* base, size_t
n, size_t size,
int (*cmp)(const void*, const void*)); base
(of n objects each of size size)
according to comparison function cmp. cmp
must return negative value if first argument is less than second, zero
if equal and positive if greater. int rand(void); 0 to RAND_MAX. void srand(unsigned int seed); seed as seed for new sequence of
pseudo-random numbers. Initial seed is 1. [Contents]
NULL size_t sizeof
operator. char* strcpy(char* s, const char* ct);
ct to s
including terminating NUL and returns s.
char* strncpy(char* s, const char* ct,
size_t n); n characters of ct
to s. Pads with NUL characters
if ct is of length less than n.
Note that this may leave s without
NUL-termination. Return s.
char* strcat(char* s, const char* ct);
ct to s
and return s. char* strncat(char* s, const char* ct,
size_t n); n characters of ct
to s. NUL-terminates s
and return it. int strcmp(const char* cs, const char* ct);
cs with ct,
returning negative value if cs<ct,
zero if cs==ct, positive value if cs>ct.
int strncmp(const char* cs, const char* ct,
size_t n); n
characters of cs and ct,
returning negative value if cs<ct,
zero if cs==ct, positive value if cs>ct.
int strcoll(const char* cs, const char* ct);
cs with ct
according to locale, returning negative value if cs<ct,
zero if cs==ct, positive value if cs>ct.
char* strchr(const char* cs, int c);
c
in cs, or NULL
if not found. char* strrchr(const char* cs, int c);
c
in cs, or NULL
if not found. size_t
strspn(const char* cs, const char* ct); cs which
consists of characters which are in ct. size_t
strcspn(const char* cs, const char* ct);
cs which
consists of characters which are not in ct.
char* strpbrk(const char* cs, const char* ct);
cs
of any character of ct, or NULL
if none is found. char* strstr(const char* cs, const char* ct);
ct
within cs, or NULL
if none is found. size_t
strlen(const char* cs); cs. char* strerror(int n);
n. char* strtok(char* s, const char* t);
s for next token delimited by
any character from ct. Non-NULL s
indicates the first call of a sequence.
If a token is found, it is NUL-terminated and returned,
otherwise NULL
is returned. ct need not be identical for each
call in a sequence. size_t
strxfrm(char* s, const char* ct, size_t n); s no more than n
characters (including terminating NUL) of a string
produced from ct according to a
locale-specific transformation. Returns length of entire
transformed string. void* memcpy(void* s,
const void* ct, size_t n);
n characters from ct
to s and returns s. s
may be corrupted if objects overlap. void* memmove(void* s, const void* ct,
size_t n); n characters from ct
to s and returns s. s
will not be corrupted if objects overlap. int memcmp(const void* cs, const void* ct,
size_t n); n
characters of cs and ct,
returning negative value if cs<ct,
zero if cs==ct, positive value if cs>ct.
void* memchr(const void* cs, int c,
size_t n); c
in first n characters of cs,
or NULL
if not found. void* memset(void* s, int c, size_t n); n characters
of s by c and returns
s. [Contents]
CLOCKS_PER_SEC clock_t
units per second. NULL clock_t time_t struct tm int tm_sec; int tm_min; int tm_hour; int tm_mday; int tm_mon; int tm_year; int tm_wday; int tm_yday; int tm_isdst; clock_t
clock(void); -1
if not available. time_t
time(time_t* tp); -1 if not
available. If tp is non-NULL,
return value is also assigned to *tp. double difftime(time_t time2,
time_t time1); time2
and time1. time_t
mktime(struct
tm* tp); *tp to
fall withing normal ranges. Returns the corresponding calendar time, or
-1 if it cannot be represented. char* asctime(const struct
tm* tp); Sun Jan 3 13:08:42 1988\n\0 char* ctime(const time_t* tp);
tp
converted to local time. Equivalent to:asctime(localtime(tp))
struct
tm* gmtime(const time_t* tp);
*tp converted to
Coordinated Universal Time, or NULL
if not available. struct
tm* localtime(const time_t*
tp); *tp converted into
local time. size_t strftime(char* s, size_t smax,
const char* fmt, const struct
tm* tp); *tp into s
according to fmt. Places no more than smax
characters into s, and returns number of
characters produced (excluding terminating NUL), or 0
if greater than smax. Formatting conversions (%c)
are:
A a B b c d 01-31] H 00-23] I 01-12] j 001-366] M 00-59] m 01-12] p AM" or "PM" S 00-61] U 00-53]
W 00-53]
w 0) [0-6]
X x Y y 00-99] Z % % Local time may differ from calendar time because of time zone.
[Contents]