Switch operand implementation for the strings

switchs.h

#ifndef __SWITCHS_H__
#define __SWITCHS_H__

#include <string.h>
#include <regex.h>
#include <stdbool.h>

/** Begin a switch for the string x */
#define switchs(x) \
    { const char *ss__sw = (x); bool ss__done = false; bool ss__cont = false; \
        regex_t ss__regex; regcomp(&ss__regex, ".*", 0); do {

/** Check if the string matches the cases argument (case sensitive) */
#define cases(x)    } if ( ss__cont || !strcmp ( ss__sw, x ) ) \
                        { ss__done = true; ss__cont = true;

/** Check if the string matches the icases argument (case insensitive) */
#define icases(x)    } if ( ss__cont || !strcasecmp ( ss__sw, x ) ) { \
                        ss__done = true; ss__cont = true;

/** Check if the string matches the specified regular expression using regcomp(3) */
#define cases_re(x,flags) } regfree ( &ss__regex ); if ( ss__cont || ( \
                              0 == regcomp ( &ss__regex, x, flags ) && \
                              0 == regexec ( &ss__regex, ss__sw, 0, NULL, 0 ) ) ) { \
                                ss__done = true; ss__cont = true;

/** Default behaviour */
#define defaults    } if ( !ss__done || ss__cont ) {

/** Close the switchs */
#define switchs_end } while ( 0 ); regfree(&ss__regex); }

#endif // __SWITCHS_H__

switchs_example.c

#include <stdio.h>
#include "switchs.h"

int main(int argc, char **argv) {
     switchs(argv[1]) {
        cases("foo")
        cases("bar")
            printf("foo or bar (case sensitive)\n");
            break;

        icases("pi")
            printf("pi or Pi or pI or PI (case insensitive)\n");
            break;

        cases_re("^D.*",0)
            printf("Something that start with D (case sensitive)\n");
            break;

        cases_re("^E.*",REG_ICASE)
            printf("Something that start with E (case insensitive)\n");
            break;

        cases("1")
            printf("1\n");

        cases("2")
            printf("2\n");
            break;

        defaults
            printf("No match\n");
            break;
    } switchs_end;
 
    return 0;
}

LOVE this. just comment out the regex line for embedded systems without glibc, etc!

Is this public domain?

Is this public domain?

Sure. You're free to use it

@develhox In the macro, switchs(x), can you change char *ss__sw = (x); to const char *ss__sw = (x); to prevent compiler warnings when passing in something with const as a qualifier of x? It shouldn't matter if the user did not pass const-qualified string too.

@hueychen27 done! thanks for the advice

@develhox Just a little note: You should add a LICENSE file to make it clear we can reuse and distribute it under some terms (preferably MIT license). Don't forget license headers, which can be concise, in the beginning of each source file as a comment.