Subversion Repositories c0or1k

/*

 * Functions to manipulate path strings.

 *

 * Copyright (C) 2008 Bahadir Balban

 */

#include <string.h>

#include <alloca.h>

/* Reverses a string by allocating on stack. Not super-efficient but easy. */

char *strreverse(char *str)

{

        int length = strlen(str);

        char *tmp = alloca(length);

        strcpy(tmp, str);

        for (int i = 0; i < length; i++)

                str[i] = tmp[length - 1 - i];

        return str;

}

/*

 * Splits the string str according to the given seperator, returns the

 * first component, and modifies the str so that it points at the next

 * available component (or a leading separator which can be filtered

 * out on a subsequent call to this function).

 */

char *splitpath(char **str, char sep)

{

        char *cursor = *str;

        char *end;

        /* Move forward until no seperator */

        while (*cursor == sep) {

                *cursor = '\0';

                cursor++;       /* Move to first char of component */

        }

        end = cursor;

        while (*end != sep && *end != '\0')

                end++;          /* Move until end of component */

        if (*end == sep) {      /* if ended with separator */

                *end = '\0';    /* finish component by null */

                if (*(end + 1) != '\0') /* if more components after, */

                        *str = end + 1; /* assign beginning to str */

                else

                        *str = end; /* else str is also depleted, give null */

        } else /* if end was null, that means the end for str, too. */

                *str = end;

        return cursor;

}

/* Same as split path, but splits components from the end. Slow. */

char *splitpath_end(char **path, char sep)

{

        char *component;

        /* Reverse the string */

        strreverse(*path);

        /* Pick one from the start */

        component = splitpath(path, sep);

        /* Reverse the rest back to original. */

        strreverse(*path);

        /* Reverse component back to original */

        strreverse(component);

        return component;

}

/* Splitpath test program. Tests all 3 functions.

int main()

{

        char str1[256] = "/a/b/c/d/////e/f";

        char *str2 = malloc(strlen(str1) + 1);

        char *comp;

        strcpy(str2, str1);

        comp = splitpath_end(&str2, '/');

        while (*comp) {

                printf("%s and %s\n", comp, str2);

                comp = splitpath_end(&str2, '/');

        }

}

*/