SAS/C Library Reference, Vol. 1

islower -- Lowercase Alphabetic Character Test

SYNOPSIS

 #include <ctype.h>

 int islower(int c);

DESCRIPTION

islower tests an integer value c to determine whether it is a lowercase alphabetic character.

RETURN VALUE

islower returns 0 if the character is not a lowercase alphabetic character, or a nonzero value if it is. If the argument is EOF, 0 is returned.

CAUTION

The effect of islower on a noncharacter argument other than EOF is undefined. The definition of a lowercase character is locale dependent. Do not assume that islower returns either 0 or 1.

EXAMPLE

  #include <ctype.h>
  #include <stdio.h>

  void main()
  {
     char id[21];
     char *text;
     int i;

     text = "passwordTESTING";

        /* Copy uppercase "identifier" from text to id. */
     for (i = 0; i < 20 && islower(text[i]); ++i)
        id[i] = text[i];
     id[i] = '0';

        /* Only the word "password" should be copied. */
     puts( id);
  }

RELATED FUNCTIONS

isalpha, isupper, tolower, toupper