rpmatch(3) Library Functions Manual rpmatch(3)
NAME
rpmatch - Determines whether a response is affirmative or negative
LIBRARY
Standard C Library (libc.a)
SYNOPSIS
#include <stdlib.h>
int rpmatch( const char *response);
PARAMETERS
User input entered in response to a question that requires an affirmative or negative answer.
DESCRIPTION
The rpmatch() function determines whether the string value of the response parameter matches the affirmative or negative response expres-
sion as specified by the LC_MESSAGES category in the program's current locale. Both response expressions, defined in the locale, may be
extended regular expressions.
A possible value of the affirmative expression, yesexpr, for a English-language locale is "^([yY]|[yY][eE][sS])". This expression will
match any value of the response parameter that has consists of the letter Y (in uppercase or lowercase) or the letters YES (in any mixture
of uppercase and lowercase letters).
EXAMPLES
The following example requests a response from the user and uses the rpmatch() function to determine if the response is affirmative or neg-
ative.
#include <stdlib.h> #include <stdio.h> #include <locale.h> #include <string.h> #define SLENGTH 80
main() {
char str[SLENGTH], *eol;
int ans;
(void)setlocale(LC_ALL, "");
printf("Do you want to perform this operation: ");
fgets(str, SLENGTH, stdin);
if ((eol = strchr(str, '
')) != NULL)
*eol = ' '; /* Replace newline with null */
else
return; /* Line entered too long */
ans = rpmatch(str);
if (ans == 1)
printf("You responded affirmatively
");
else if (ans == 0)
printf("You responded negatively
");
else
printf("Your answer did not match
"); }
RETURN VALUES
A value of 1 is returned if the string value of the response parameter is matched by the affirmative expression; a value of 0 (zero) is
returned if the string value of the response parameter is matched by the negative expression. If neither expression matches the string
value of the response parameter, a value of -1 is returned.
RELATED INFORMATION
Commands: grep(1).
Functions: regcomp(3), regexec(3), setlocale(3).
Files: locale(4). delim off
rpmatch(3)
