INTRO(3) UNIX Programmer's Manual INTRO(3) NAME intro - introduction to C library functions DESCRIPTION This section describes functions that may be found in vari- ous libraries. The library functions are those other than the functions which directly invoke UNIX system primitives, described in section 2. Most of these functions are acces- sible from the C library, _l_i_b_c, which is automatically loaded by the C compiler _c_c(1), and the Pascal compiler _p_c(1). The link editor _l_d(1) searches this library under the `-lc' option. The C library also includes all the func- tions described in section 2. A subset of these functions are available from Fortran; they are described separately in _i_n_t_r_o(3F). The functions described in this section are grouped into various sections: (3) The straight ``3'' functions are the standard C library functions. (3N) These functions constitute the internet network library. (3S) These functions constitute the `standard I/O package', see _s_t_d_i_o(3S) for more details. Declarations for these functions may be obtained from the include file <_s_t_d_i_o._h>. (3C) These routines are included for compatibility with other systems. In particular, a number of system call interfaces provided in previous releases of 4BSD have been included for source code compatibility. Use of these routines should, for the most part, be avoided. The manual page entry for each compatibility routine indicates the proper interface to use. (3M) These functions constitute the math library, _l_i_b_m. When functions in the math library (see _m_a_t_h(3M)) are passed values that are undefined or would generate answers that are out of range, they call the _i_n_f_n_a_n routine. By default this routine returns the VAX reserved floating point value which causes the process to get a floating point exception (see _s_i_g_v_e_c(2)). Programs that wish to take other action should define their own version of _i_n_f_n_a_n (see _i_n_f_n_a_n(3M) for details). The math library is loaded as needed by the Pascal compiler _p_c(1). C programs that wish to use this library need to specify the ``-lm'' option. Printed 11/26/99 May 27, 1986 1 INTRO(3) UNIX Programmer's Manual INTRO(3) (3X) These functions constitute minor libraries and other miscellaneous run-time facilities. Most are available only when programming in C. These functions include libraries that provide device independent plotting functions, terminal independent screen management rou- tines for two dimensional non-bitmap display terminals, and functions for managing data bases with inverted indexes. These functions are located in separate libraries indicated in each manual entry. FILES /lib/libc.a the C library /usr/lib/libm.a the math library /usr/lib/libc_p.a the C library compiled for profiling /usr/lib/libm_p.a the math library compiled for profiling SEE ALSO stdio(3S), math(3M), intro(2), cc(1), ld(1), nm(1) LIST OF FUNCTIONS _N_a_m_e _A_p_p_e_a_r_s _o_n _P_a_g_e _D_e_s_c_r_i_p_t_i_o_n abort abort.3 generate a fault abs abs.3 integer absolute value acos sin.3m inverse trigonometric function acosh asinh.3m inverse hyperbolic function alarm alarm.3c schedule signal after specified time alloca malloc.3 memory allocator arc plot.3x graphics interface asctime ctime.3 convert date and time to ASCII asin sin.3m inverse trigonometric function asinh asinh.3m inverse hyperbolic function assert assert.3x program verification atan sin.3m inverse trigonometric function atanh asinh.3m inverse hyperbolic function atan2 sin.3m inverse trigonometric function atof atof.3 convert ASCII to numbers atoi atof.3 convert ASCII to numbers atol atof.3 convert ASCII to numbers bcmp bstring.3 bit and byte string operations bcopy bstring.3 bit and byte string operations bzero bstring.3 bit and byte string operations cabs hypot.3m complex absolute value calloc malloc.3 memory allocator cbrt sqrt.3m cube root ceil floor.3m integer no less than circle plot.3x graphics interface clearerr ferror.3s stream status inquiries closedir directory.3 directory operations closelog syslog.3 control system log closepl plot.3x graphics interface cont plot.3x graphics interface copysign ieee.3m copy sign bit Printed 11/26/99 May 27, 1986 2 INTRO(3) UNIX Programmer's Manual INTRO(3) cos sin.3m trigonometric function cosh sinh.3m hyperbolic function crypt crypt.3 DES encryption ctime ctime.3 convert date and time to ASCII curses curses.3x screen functions with ``optimal'' cursor motion dbminit dbm.3x data base subroutines delete dbm.3x data base subroutines drem ieee.3m remainder ecvt ecvt.3 output conversion edata end.3 last locations in program encrypt crypt.3 DES encryption end end.3 last locations in program endfsent getfsent.3x get file system descriptor file entry endgrent getgrent.3 get group file entry endhostent gethostbyname.3n get network host entry endnetent getnetent.3n get network entry endprotoent getprotoent.3n get protocol entry endpwent getpwent.3 get password file entry endservent getservent.3n get service entry environ execl.3 execute a file erase plot.3x graphics interface erf erf.3m error function erfc erf.3m complementary error function etext end.3 last locations in program exec execl.3 execute a file exece execl.3 execute a file execl execl.3 execute a file execle execl.3 execute a file execlp execl.3 execute a file exect execl.3 execute a file execv execl.3 execute a file execvp execl.3 execute a file exit exit.3 terminate a process after flushing any pending output exp exp.3m exponential expm1 exp.3m exp(x)-1 fabs floor.3m absolute value fclose fclose.3s close or flush a stream fcvt ecvt.3 output conversion feof ferror.3s stream status inquiries ferror ferror.3s stream status inquiries fetch dbm.3x data base subroutines fflush fclose.3s close or flush a stream ffs bstring.3 bit and byte string operations fgetc getc.3s get character or word from stream fgets gets.3s get a string from a stream fileno ferror.3s stream status inquiries firstkey dbm.3x data base subroutines floor floor.3m integer no greater than fopen fopen.3s open a stream fprintf printf.3s formatted output conversion fputc putc.3s put character or word on a stream fputs puts.3s put a string on a stream Printed 11/26/99 May 27, 1986 3 INTRO(3) UNIX Programmer's Manual INTRO(3) fread fread.3s buffered binary input/output free malloc.3 memory allocator frexp frexp.3 split into mantissa and exponent fscanf scanf.3s formatted input conversion fseek fseek.3s reposition a stream ftell fseek.3s reposition a stream ftime time.3c get date and time fwrite fread.3s buffered binary input/output gcvt ecvt.3 output conversion getc getc.3s get character or word from stream getchar getc.3s get character or word from stream getdiskbyname getdisk.3x get disk description by its name getenv getenv.3 value for environment name getfsent getfsent.3x get file system descriptor file entry getfsfile getfsent.3x get file system descriptor file entry getfsspec getfsent.3x get file system descriptor file entry getfstype getfsent.3x get file system descriptor file entry getgrent getgrent.3 get group file entry getgrgid getgrent.3 get group file entry getgrnam getgrent.3 get group file entry gethostbyaddr gethostbyname.3n get network host entry gethostbyname gethostbyname.3n get network host entry gethostent gethostbyname.3n get network host entry getlogin getlogin.3 get login name getnetbyaddr getnetent.3n get network entry getnetbyname getnetent.3n get network entry getnetent getnetent.3n get network entry getpass getpass.3 read a password getprotobyname getprotoent.3n get protocol entry getprotobynumber getprotoent.3n get protocol entry getprotoent getprotoent.3n get protocol entry getpw getpw.3 get name from uid getpwent getpwent.3 get password file entry getpwnam getpwent.3 get password file entry getpwuid getpwent.3 get password file entry gets gets.3s get a string from a stream getservbyname getservent.3n get service entry getservbyport getservent.3n get service entry getservent getservent.3n get service entry getw getc.3s get character or word from stream getwd getwd.3 get current working directory pathname gmtime ctime.3 convert date and time to ASCII gtty stty.3c set and get terminal state (defunct) htonl byteorder.3n convert values between host and network byte order htons byteorder.3n convert values between host and network byte order hypot hypot.3m Euclidean distance index string.3 string operations inet_addr inet.3n Internet address manipulation routines inet_lnaof inet.3n Internet address manipulation routines inet_makeaddr inet.3n Internet address manipulation routines inet_netof inet.3n Internet address manipulation routines inet_network inet.3n Internet address manipulation routines Printed 11/26/99 May 27, 1986 4 INTRO(3) UNIX Programmer's Manual INTRO(3) infnan infnan.3m signals exceptions initgroups initgroups.3x initialize group access list initstate random.3 better random number generator insque insque.3 insert/remove element from a queue isalnum ctype.3 character classification macros isalpha ctype.3 character classification macros isascii ctype.3 character classification macros isatty ttyname.3 find name of a terminal iscntrl ctype.3 character classification macros isdigit ctype.3 character classification macros islower ctype.3 character classification macros isprint ctype.3 character classification macros ispunct ctype.3 character classification macros isspace ctype.3 character classification macros isupper ctype.3 character classification macros j0 j0.3m bessel function j1 j0.3m bessel function jn j0.3m bessel function label plot.3x graphics interface ldexp frexp.3 split into mantissa and exponent lgamma lgamma.3m log gamma function; (formerly gamma.3m) lib2648 lib2648.3x subroutines for the HP 2648 graphics terminal line plot.3x graphics interface linemod plot.3x graphics interface localtime ctime.3 convert date and time to ASCII log exp.3m natural logarithm logb ieee.3m exponent extraction log10 exp.3m logarithm to base 10 log1p exp.3m log(1+x) longjmp setjmp.3 non-local goto malloc malloc.3 memory allocator mktemp mktemp.3 make a unique file name modf frexp.3 split into mantissa and exponent moncontrol monitor.3 prepare execution profile monitor monitor.3 prepare execution profile monstartup monitor.3 prepare execution profile move plot.3x graphics interface nextkey dbm.3x data base subroutines nice nice.3c set program priority nlist nlist.3 get entries from name list ntohl byteorder.3n convert values between host and network byte order ntohs byteorder.3n convert values between host and network byte order opendir directory.3 directory operations openlog syslog.3 control system log openpl plot.3x graphics interface pause pause.3c stop until signal pclose popen.3 initiate I/O to/from a process perror perror.3 system error messages point plot.3x graphics interface popen popen.3 initiate I/O to/from a process pow exp.3m exponential x**y printf printf.3s formatted output conversion Printed 11/26/99 May 27, 1986 5 INTRO(3) UNIX Programmer's Manual INTRO(3) psignal psignal.3 system signal messages putc putc.3s put character or word on a stream putchar putc.3s put character or word on a stream puts puts.3s put a string on a stream putw putc.3s put character or word on a stream qsort qsort.3 quicker sort rand rand.3c random number generator random random.3 better random number generator rcmd rcmd.3x routines for returning a stream to a remote command re_comp regex.3 regular expression handler re_exec regex.3 regular expression handler readdir directory.3 directory operations realloc malloc.3 memory allocator remque insque.3 insert/remove element from a queue rewind fseek.3s reposition a stream rewinddir directory.3 directory operations rexec rexec.3x return stream to a remote command rindex string.3 string operations rint floor.3m round to nearest integer rresvport rcmd.3x routines for returning a stream to a remote command ruserok rcmd.3x routines for returning a stream to a remote command scalb ieee.3m exponent adjustment scandir scandir.3 scan a directory scanf scanf.3s formatted input conversion seekdir directory.3 directory operations setbuf setbuf.3s assign buffering to a stream setbuffer setbuf.3s assign buffering to a stream setegid setuid.3 set user and group ID seteuid setuid.3 set user and group ID setfsent getfsent.3x get file system descriptor file entry setgid setuid.3 set user and group ID setgrent getgrent.3 get group file entry sethostent gethostbyname.3n get network host entry setjmp setjmp.3 non-local goto setkey crypt.3 DES encryption setlinebuf setbuf.3s assign buffering to a stream setnetent getnetent.3n get network entry setprotoent getprotoent.3n get protocol entry setpwent getpwent.3 get password file entry setrgid setuid.3 set user and group ID setruid setuid.3 set user and group ID setservent getservent.3n get service entry setstate random.3 better random number generator setuid setuid.3 set user and group ID signal signal.3 simplified software signal facilities sin sin.3m trigonometric function sinh sinh.3m hyperbolic function sleep sleep.3 suspend execution for interval space plot.3x graphics interface sprintf printf.3s formatted output conversion sqrt sqrt.3m square root srand rand.3c random number generator Printed 11/26/99 May 27, 1986 6 INTRO(3) UNIX Programmer's Manual INTRO(3) srandom random.3 better random number generator sscanf scanf.3s formatted input conversion stdio intro.3s standard buffered input/output package store dbm.3x data base subroutines strcat string.3 string operations strcmp string.3 string operations strcpy string.3 string operations strlen string.3 string operations strncat string.3 string operations strncmp string.3 string operations strncpy string.3 string operations stty stty.3c set and get terminal state (defunct) swab swab.3 swap bytes sys_errlist perror.3 system error messages sys_nerr perror.3 system error messages sys_siglist psignal.3 system signal messages syslog syslog.3 control system log system system.3 issue a shell command tan sin.3m trigonometric function tanh sinh.3m hyperbolic function telldir directory.3 directory operations tgetent termcap.3x terminal independent operation routines tgetflag termcap.3x terminal independent operation routines tgetnum termcap.3x terminal independent operation routines tgetstr termcap.3x terminal independent operation routines tgoto termcap.3x terminal independent operation routines time time.3c get date and time times times.3c get process times timezone ctime.3 convert date and time to ASCII tputs termcap.3x terminal independent operation routines ttyname ttyname.3 find name of a terminal ttyslot ttyname.3 find name of a terminal ungetc ungetc.3s push character back into input stream utime utime.3c set file times valloc valloc.3 aligned memory allocator varargs varargs.3 variable argument list vlimit vlimit.3c control maximum system resource consumption vtimes vtimes.3c get information about resource utilization y0 j0.3m bessel function y1 j0.3m bessel function yn j0.3m bessel function Printed 11/26/99 May 27, 1986 7