isdigit(3)                          CLIX                          isdigit(3)



  NAME

    isdigit - Tests whether a character is a digit

  LIBRARY

    Standard C Library (libc.a)

  SYNOPSIS

    #include <ctype.h>

    int isdigit(
      int c );

  PARAMETERS

    c  An integer representing a character

  DESCRIPTION

    The isdigit() macro tests for the digits 0 through 9.  The isdigit() macro
    is defined on valid members of the character set and on the single value
    EOF (guaranteed not to be a character set member.  See stdio.

    The classification macro isdigit() does a table lookup.

  EXAMPLES

    To test if the character read from stdin is a zero-to-nine digit:

    #include <ctype.h>
    int c;
       .
       .
       .
    /* get a character from stdin */
    printf("enter a character:");
    c = getchar();

    /* check to see if a digit was read */
    if (isdigit(c))
    {
         printf("read a digit"\n);
    }


  CAUTIONS

    If the argument to any character handling macro is not in the domain of
    the function, the result is undefined.



  2/94 - Intergraph Corporation                                              1

  isdigit(3)                          CLIX                          isdigit(3)



  RETURN VALUES

    The isdigit() macro returns 0 for false and nonzero numbers for true.

  RELATED INFORMATION

    Commands:  chrtbl(1)

    Functions:  isxdigit(3), islower(3), isupper(3), isalpha(3), isalnum(3),
    isspace(3), iscntrl(3), ispunct(3), isprint(3), isgraph(3), isascii(3),
    tolower(3), toupper(3), toascci(3), _tolower(3), _toupper(3),
    setchrclass(3)

    Files:  stdio(3)

    Miscellany:  environ(4)






































  2                                              Intergraph Corporation - 2/94