mktime()—Converts time formats 363
modf()—Breaks a value into integral and fractional parts 364
open()—Opens a file 365
opendir()—Opens a directory 367
pathconf()—Gets configuration variables for a path 368
pause()—Suspends process execution 370
perror()—Prints an error message 371
pipe()—Creates an interprocess channel 372
pow()—Computes x raised to the power y 373
printff()—Writes formatted text to the standard output stream 374
putc()—Writes a character to a stream 378
putchar()—Writes a character to standard output 379
puts( )—Writes a string to standard output 380
qsort()—Sorts an array 381
raise()—Sends a signal 383
rand()—Retums a random number 384
read()—Reads from a file 385
readdir()—Reads a directory 387
realloc()—Changes the size of a memory object 389
remove()—Removes a file from a directory 390
rename()—Renames a file 391
rewind()—Sets the file position to the beginning of the file 393
rewinddir()—Resets the readdir() pointer 394
rmdir()—Removes a directory 395
scanf()—Reads formatted text from standard input stream 396
setbuf()—Determines how a stream will be buffered 400
setgid()—Sets group ID 401
setjmp()—Saves the calling environment for use by longjmp() 403
setlocale()—Sets or queries a program's locale 405
setpgid()—Sets process group ID for job control 406
setsid()—Creates a session and sets the process group ID 407
setuid()—Sets the user ID 408
setvbuf()—Determines buffering for a stream 410
sigaction()—Examines and changes signal action 412
sigaddset()—Adds a signal to a signal set 414
sigdelset()—Removes a signal from a signal set 415
sigemptyset()—Creates an empty signal set 416
sigfillset()—Creates a full set of signals 417
sigismember()—Tests a signal set for a selected member 418
siglongjmp()—Goes to and restores signal mask 419
signal()—Specifies signal handling 420
sigpending()—Examines pending signals 422
sigprocmask()—Examines and changes blocked signals 423
sigsetjmp()—Saves state for siglongjmp() 425
sigsuspend()—Waits for a signal 427
sin()—Computes the sine function 428
sinh()—Computes the hyperbolic sine of x 429
sleep()—Delays process execution 430
sprintf()—Formats a string 431
sqrt()—Computes the square root function 435
srand()—Sets a seed for the rand() function 436
sscanf()—Parses a string 437
stat()—Gets information about a file 441
strcat()—Concatenates two strings 442
strchr()—Scans a string for a character 443
strcmp()—Compares two strings 444
strcoll()—Compares two strings using the current locale 445
strcpy()—Copies a string 446
strcspn()—Searches a string for characters which are not in the second string
strerror()—Converts an error number to a string 448
strftime()—Formats date/time 449
strlen()—Computes the length of a string 451
strcat()—Concatenates two counted strings 452
strncmp()—Compares two counted strings 453
strncpy()—Copies a counted string 454
strpbrk()—Searches a string for any of a set of characters 455
strrchr()—Locates the last occurrence of a character in a string 456
strspn()—Searches a string for any of a set of characters 457
strstr()—Locates a substring 458
strtod()—Converts a string to double 459
strtok()—Breaks a string into tokens 461
strtol()—Converts a string to long int 462
strtoul()—Converts a string to unsigned long int 464
strxfrm()—Transforms strings using rules for locale 466
sysconf()—Gets system configuration information 468
system()—Executes a command 470
tan()—Computes the tangent of x 471
tanh()—Computes the hyperbolic tangent of x 472
tcdrain()—Waits for all output to be transmitted to the terminal 473
tcflow()—Suspends/restarts terminal output 474
tcflush()—Discards terminal data 476
tcgetattr()—Gets terminal attributes 477
tcgetpgrp()—Gets foreground process group ID 478
tcsendbreak()—Sends a break to a terminal 480
tcsetattr()—Sets terminal attributes 481
tcsetpgrp()—Sets foreground process group ID 483
time()—Determines the current calendar time 484
times()—Gets process times 485
tmpfile()—Creates a temporary file 486
tmpnam()—Generates a string that is a valid non-existing file name 487
tolower()—Converts uppercase to lowercase 488
toupper()—Converts lowercase to uppercase 489
ttyname()—Determines a terminal pathname 490
tzset()—Sets the timezone from environment variables 491
umask()—Sets a file creation mask 492
uname()—Gets system name 493
ungetc()—Pushes a character back onto a stream 495
unlink()—Removes a directory entry 496
utime()—Sets file access and modification times 497
va_arg()—Gets the next argument 499
va_end()—Ends variable argument list 501
va_start()—Starts a variable argument list 502
vfprintf()—Writes formatted text with a variable argument list 503
vprintf()—Write formatted text to standard output with a variable argument list
vsprintf()—Write formatted text to a string with a variable argument list
wait()—Waits for process termination 507
waitpid()—Waits for process termination 509
wcstombs()—Converts a wide character string to a multibyte character string
wctomb()—Converts a wide character to a multibyte character 512
write()—Writes to a file
abort()— Causes abnormal process termination 211
abs()—Computes the absolute value of an integer 212
access()—Tests for file accessibility 213
acos()—Computes the principal value of arc cosine 215
alarm()—Schedules an alarm 216
asctime()—Converts a time structure to a string 217
asin()—Computes the principal value of the arc sine 218
assert()—Aborts the program if assertion is false 219
atan()—Computes the principal value of the arc tangent 221
atan2()—Computes the principal value of the arc tangent of y/x 222
atexit()—Registers a function to be called at normal program termination
atof()—Converts a text string to double 224
atoi()—Converts a text string to integer 225
atol()—Converts a text string to long integer 226
bsearch()—Searches a sorted array 227
calloc()—Allocates and zeroes memory 229
ceil()—Computes the smallest integer greater than or equal to x 230
cfgetispeed()—Reads terminal input baud rate 231
cfgetospeed()—Reads terminal output baud rate 232
cfsetispeed()—Sets terminal input baud rate 233
cfsetospeed()—Sets terminal output baud rate 234
chdir()—Changes the current working directory 235
chmod()—Changes file mode 236
chown()—Changes the owner and/or group of a file 238
clearerr()—Clears end—of-file and error indicators for a stream 240
clock( )—Determines processor time used 241
close()—Closes a file 242
closedir()—Ends directory read operation 243
cos()—Computes the cosine function 244
cosh()—Computes the hyperbolic cosine function 245
creat()—Creates a new file or rewrites an existing one 246
ctermid()—Generates terminal pathname 247
ctime()—Formats a calendar time 248
cuserid()—Gets user name 249
difftime()—Computes the difference between two times 250
div()—Computes the quotient and remainder of an integer division 251
dup()—Duplicates an open file descriptor 252
dup2()——Duplicates an open file descriptor 253
execl()—Executes a file 254
execle()—Executes a file 256
execlp()—Executes a file 258
execv()—Executes a file 260
execve()—Executes a file 262
execvp()—Executes a file 264
exit()—Causes normal program termination 266
_exit()—Terminates a process 267
exp()—Computes the exponential function 268
fabs()—Computes the absolute-value function 269
fclose()—Closes an open stream 270
fcntl()—Manipulates an open file descriptor 271
fdopen()—Opens a stream on a file descriptor 274
feoff()—Tests the end-of-file indicator for a stream 275
ferror()—Tests the error indicator for a stream 276
fflush()—Updates stream 277
fgetc()—Reads a character from a stream 278
fgetpos()—Gets the current file position 279
fgets( )—Reads n characters from a stream 280
fileno()—Maps a stream pointer to a file descriptor 281
floor( )—Computes the largest integer not greater than x 282
fmod()—Computes the remainder of x/y 283
fopen()—Opens a stream 284
fork()—Creates a process 285
fpathconf()—Gets configuration variable for an open file 287
fprintf( )—Writes formatted text to a stream 289
fputc( )—Writes a character to a stream 293
fputs()—Writes a string to a stream 294
fread()—Reads an array from a stream 295
free()—Deallocates dynamic memory 296
freopen()—Closes and then opens a stream 297
frexp()—Breaks a floating-point number into a fraction and integer 298
fscanf( )—Reads formatted input from a stream 299
fseek()—Sets file position 302
fsetpos()—Sets the file position for a stream 303
fstat()—Gets file status 304
ftell()—Gets the position indicator for a stream 305
fwrite()—Writes an array to a stream 306
getc()—Reads a character from a stream 307
getchar()—Reads a character from standard input 308
getcwd()—Gets current working directory 309
getegid()—Gets effective group ID 310
getenv()—Gets the environment variable 311
geteuid()—Gets effective user ID 313
getgid()—Gets real group ID 314
getgrgid()—Reads groups database based on group ID 315
getgrnam)—Reads group database based on group name 316
getgroups()—Gets supplementary group IDs 317
getlogin()—Gets user name 319
getpgrp()—Gets process group ID 320
getpid()—Gets process ID 321
getppid()—Gets parent process ID 322
getpwnam()—Reads user database based on user name 323
getpwuid()—Reads user database based on user ID 324
gets()—Reads a string from standard input 325
getuid()—Gets real user ID 326
gmtime()—Breaks down a timer value into a time structure in
Coordinated Universal Time (UTC)
isalnum()—Tests for alphabetic or numeric character 328
isalpha()—Tests for alphabetic character 329
isatty( )—Determines if a file descriptor is associated with a terminal 330
iscntrl()—Tests for control character 331
isdigit()—Tests for decimal-digit character 332
isgraph()—Tests for printing character 333
islower()—Tests for lowercase character 334
isprint()—Tests for printing character 335
ispunct()—Tests for punctuation 336
isspace()—Tests for white-space character 337
isupper()—Tests for uppercase alphabetic character 338
isxdigit()—Tests for hexadecimal-digit character 339
kill()—Sends a signal to a process 340
labs()—Computes the absolute value of a long integer 341
ldexp()—Multiplies a floating-point number by a power of 2 342
ldiv()—Computes the quotient and remainder of integer division 343
link()—Creates a link to a file 344
localeconv()—Gets rules to format numeric quantities for the current locale
localtime()—Breaks down a timer value into a time structure in local time
log()—Computes the natural log function 347
loglO()—Computes the base-ten logarithm function 348
longjmp()—Restores the calling environment 349
lseek()—Repositions read/write file offset 350
malloc()—Allocates dynamic memory 352
mblen()—Determines the number of bytes in a character 353
mbstowcs()—Converts a multibyte string to a wide-character string 354
mbtowc()—Converts a multibyte character to a wide character 355
memchr()—Scans memory for a byte 356
memcmp()—Compares two memory objects 357
memcpy()—Copies non-overlapping memory objects 358
memmove()—Copies (possibly overlapping) memory objects 359
memset( )—Fills memory with a constant byte 360
mkdir()—Makes a directory 361
mkfifo()—Makes a FIFO special file 362