isupper

isupper

Uppercase Alphabetic Character Test

Portability: ISO/ANSI C conforming, UNIX compatible

SYNOPSIS
DESCRIPTION
RETURN VALUE
CAUTION
EXAMPLE
RELATED FUNCTIONS
SEE ALSO

SYNOPSIS

#include <ctype.h>

int isupper(int c);

DESCRIPTION

isupper tests an integer value c to determine whether it is an uppercase alphabetic character.

RETURN VALUE

isupper returns 0 if the character is not an uppercase alphabetic character, or a nonzero value if it is. If the argument is EOF , 0 is returned.

CAUTION

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

EXAMPLE

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

#define MAXLEN 40

main()
{
   char id[MAXLEN +1];
   char *text;
   char input[MAXLEN +1];
   int i;

   printf("Enter a string (maximum of %d characters):\n", MAXLEN);
   text = gets(input);

      /* Copy uppercase "identifier" from text to id.           */
   for (i = 0; i < 40 && isupper(text[i]); ++i)
      id[i] = text[i];

   id[i] = '\0';

      /* Only initial uppercase characters get copied.          */
   printf("%s\n", id);
}

RELATED FUNCTIONS

isalpha , islower , tolower , toupper

SEE ALSO

Chapter 10, "Localization," in SAS/C Library Reference, Volume 2
Character Type Macros and Functions

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