(From Ross Richardson, University of Tasmania)
<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 functionsvoid 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 mantissaFLT_MAX
DBL_MAX
LDBL_MAX
FLT_MAX_EXP
DBL_MAX_EXP
LDBL_MAX_EXP
FLT_RADIX
can be raised and remain representableFLT_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 valueschar n_sep_by_space;
1
) or is not (0
) separated by space from negative monetary valueschar n_sign_posn;
0
1
2
3
4
char p_cs_precedes;
1
) or follows (0
) positive monetary valueschar p_sep_by_space;
1
) or is not (0
) separated by space from non-negative monetary valueschar 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 categoriesLC_NUMERIC
category
for numeric formatting informationLC_MONETARY
category
for monetary formatting informationLC_COLLATE
category
for information affecting collating functionsLC_CTYPE
category
for information affecting character class tests functionsLC_TIME
category
for information affecting time conversions functionsNULL
[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 zerodouble 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-defineddouble 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 errorSIG_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_END
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 notationo
int
argument, printed in unsigned octal notationx,X
int
argument, printed in unsigned hexadecimal notationu
int
argument, printed in unsigned decimal notationc
int
argument, printed as single characters
char*
argumentf
double
argument, printed with format [-
]mmm.
ddde,E
double
argument, printed with format [-
]m.
dddddd(e
|E
)(+
|-
)xxg,G
double
argumentp
void*
argument, printed as pointern
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 requiredi
int*
parameter required; decimal, octal or hexo
int*
parameter requiredu
unsigned int*
parameter requiredx
int*
parameter requiredc
char*
parameter required; white-space is not skipped, and NUL
-termination is not performeds
char*
parameter required; string is NUL
-terminatede,f,g
float*
parameter requiredp
void*
parameter requiredn
int*
parameter required[...]
char*
parameter required; string is NUL
-terminated[^...]
char*
parameter required; string is NUL
-terminated%
%
; no assignmentint 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]