This documentation is copyright © 1998-2001 Sandro Sigala <sandro@sigala.it>.
All rights reserved.

Released under the GNU General Public License.

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isalpha

Prototype

#include <ctype.h>

int isalpha(int c);

Description

In the ``C'' locale, returns a true value for the characters for which isupper or islower is true. In other implementation-defined set of characters returns true for the characters for which none of iscntrl, isdigit, ispunct, or isspace is true.

Example

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

/*
 * Return the next word read the standard input.
 */
char *get_word(char *buf)
{
    char *dp = buf;
    int c;

    while (isalpha(c = getchar()))
	*dp++ = c;
    if (c != EOF)
	ungetc(c, stdin);
    *dp = '\0';

    return buf;
}

References

ISO C 9899:1990 7.3.1.2