limits(4)




NAME

     limits - header for implementation-specific constants


SYNOPSIS

     #include <limits.h>


DESCRIPTION

     The header <limits.h> is a list of minimal magnitude limita-
     tions  imposed by a specific implementation of the operating
     system.

     _ARG_MAX32     1048320                      /* max length of arguments to  exec
                                                 32-bit program */
     _ARG_MAX64     2096640                      /* max length of arguments to  exec
                                                 64-bit program */
     CHAR_BIT       8                            /* max # of bits in a char */
     CHAR_MAX       255                          /* max value of a char */
     CHAR_MIN       0                            /* min value of a char */
     CHILD_MAX      25                           /* max # of processes per  user  id
                                                 */
     CLK_TCK        _sysconf(3)                  /* clock ticks per second */
     DBL_DIG        15                           /* digits of precision of a  double
                                                 */
     DBL_MAX        1.7976931348623157E+308      /* max decimal value of a double*/
     DBL_MIN        2.2250738585072014E-308      /* min decimal value of a double*/
     FCHR_MAX       1048576                      /*  historical  default  file  size
                                                 limit in bytes */
     FLT_DIG        6                            /* digits of precision of  a  float
                                                 */
     FLT_MAX        3.40282347e+38F              /* max decimal value of a float */
     FLT_MIN        1.17549435E-38F              /* min decimal value of a float */
     INT_MAX        2147483647                   /* max value of an int */
     INT_MIN        (-2147483647-1)              /* min value of an int */
     LINK_MAX       1000                         /* max # of links to a single  file
                                                 */
     LOGNAME_MAX    8                            /* max # of characters in  a  login
                                                 name */
     LONG_BIT       32                           /* # of bits in a long */
     LONG_MAX       2147483647L                  /* max  value  of  a  long  int  if
                                                 _ILP32 defined */
                    9223372036854775807L         /* max value of a long int if _LP64
                                                 defined */
     LONG_MIN       (-2147483647-1L)             /* min  value  of  a  long  int  if
                                                 _ILP32 defined */
                    (-9223372036854775807L-1L)   /* min value of a long int if _LP64
                                                 defined */
     MAX_CANON      256                          /* max bytes in a line for  canoni-
                                                 cal processing */
     MAX_INPUT      512                          /* max size of a char input  buffer
                                                 */

     MB_LEN_MAX     5                            /* max # of bytes  in  a  multibyte
                                                 character */
     NAME_MAX       14                           /* max # of characters  in  a  file
                                                 name */
     NGROUPS_MAX    16                           /* max # of groups for a user */
     NL_ARGMAX      9                            /* max value of "digit" in calls to
                                                 the
                                                 NLS printf() and scanf() */
     NL_LANGMAX     14                           /* max # of bytes in a LANG name */
     NL_MSGMAX      32767                        /* max message number */
     NL_NMAX        1                            /* max # of bytes in N-to-1 mapping
                                                 characters */
     NL_SETMAX      255                          /* max set number */
     NL_TEXTMAX     255                          /* max #  of  bytes  in  a  message
                                                 string */
     NZERO          20                           /* default process priority */
     OPEN_MAX       20                           /* max # of  files  a  process  can
                                                 have open */
     PASS_MAX       8                            /* max # of characters in  a  pass-
                                                 word */
     PATH_MAX       1024                         /* max # of characters  in  a  path
                                                 name */
     PID_MAX        999999                       /* max value for a process ID */
     PIPE_BUF       5120                         /* max # bytes atomic in write to a
                                                 pipe */
     PIPE_MAX       5120                         /* max # bytes written to a pipe in
                                                 a write */
     SCHAR_MAX      127                          /* max value of a "signed char" */
     SCHAR_MIN      (-128)                       /* min value of a "signed char" */
     SHRT_MAX       32767                        /* max value of a "short int" */
     SHRT_MIN       (-32768)                     /* min value of a "short int" */
     STD_BLK        1024                         /* # bytes in a physical I/O  block
                                                 */
     SYS_NMLN       257                          /* 4.0 size of utsname elements */
                                                 /* also defined in sys/utsname.h */
     SYSPID_MAX     1                            /* max pid of system processes */
     TMP_MAX        17576                        /* max # of unique names  generated
                                                 by tmpnam */
     UCHAR_MAX      255                          /* max value of an "unsigned  char"
                                                 */
     UID_MAX        2147483647                   /* max value for a user or group ID
                                                 */
     UINT_MAX       4294967295                   /* max value of an  "unsigned  int"
                                                 */
     ULONG_MAX      4294967295UL                 /* max value of an  "unsigned  long
                                                 int" if _ILP32 defined */
                    18446744073709551615UL       /* max value of an  "unsigned  long
                                                 int" if _LP64 defined */
     USHRT_MAX      65535                        /* max value of an "unsigned  short
                                                 int" */

     USI_MAX        4294967295                   /*  max   decimal   value   of   an
                                                 "unsigned" */
     WORD_BIT       32                           /* # of bits in a word or int */

     The following POSIX definitions  are  the  most  restrictive
     values  to  be  used by a  POSIX-conforming application (see
     standards(5)).  Conforming  implementations  shall   provide
     values at least this large.

     _POSIX_ARG_MAX         4096       /* max length of arguments to exec
                                       */
     _POSIX_CHILD_MAX       6          /* max # of processes per user  ID
                                       */
     _POSIX_LINK_MAX        8          /* max # of links to a single file
                                       */
     _POSIX_MAX_CANON       255        /* max # of bytes  in  a  line  of
                                       input */
     _POSIX_MAX_INPUT       255        /* max  #  of  bytes  in  terminal
                                       input queue */
     _POSIX_NAME_MAX        14         /* # of bytes in a filename */
     _POSIX_NGROUPS_MAX      0         /* max # of groups in a process */
     _POSIX_OPEN_MAX        16         /* max # of files  a  process  can
                                       have open */
     _POSIX_PATH_MAX        255        /* max # of characters in a  path-
                                       name */
     _POSIX_PIPE_BUF        512        /* max # of bytes atomic in  write
                                       to a pipe */


SEE ALSO

     standards(5)


Man(1) output converted with man2html