C split/join functions, using strtok_r -- Source

string_sj.c

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "string_sj.h"

int str_split(const char* src, const char* delims, char*** dest) {
    char *s = strdup(src);
    char *c, *saveptr, *tmp;
    void *_tmp;
    int num_tokens = 0, num_size = 10;
    c = strtok_r(s, delims, &saveptr);
    if (c == NULL)
        return 0;
        
    *dest = malloc(num_size * sizeof(char*));
    if (*dest == NULL) 
        return -1;
    
    tmp = strdup(c);
    if (tmp == NULL) {
        free(*dest);
        free(s);
        *dest = NULL;
        return -1;
    }
    
    (*dest)[num_tokens] = tmp;
    num_tokens++;
    
    while ((c = strtok_r(NULL, delims, &saveptr)) != NULL) {
        if (num_tokens == num_size) {
            num_size += 10;
            _tmp = realloc(*dest, num_size*sizeof(char*));
            if (!_tmp) {
                fprintf(stderr, "ERROR: split() cannot realloc() memory needed.");
                return -1;
            }
            *dest = (char**)_tmp;
        }
        tmp = strdup(c);
        if (tmp == NULL) {
            free(*dest);
            free(s);
            *dest = NULL;
            return -1;
        }
        
        (*dest)[num_tokens] = tmp;
        num_tokens++;
    }
    return num_tokens;
}

char *str_join(char** items, int start, int end, const char* delim) {
    int i;
    char *tmp = NULL;
    int dlen = strlen(delim);
    int total_size = 0;
    
    if ((end - start) < 1 || start >= end) {
        return strdup("");
    } else if ((end - start) == 1) {
        return strdup(items[start]);
    }
    
    total_size += strlen(items[start]);
    for (i = start+1; i < end; i++) {
        total_size += dlen;
        total_size += strlen(items[i]);
    }
    
    tmp = (char*)malloc(total_size * sizeof(char));
    if (tmp == NULL)
        return NULL;
    
    strcat(tmp, items[start]);
    for (i = start+1; i < end; i++) {
        strcat(tmp, delim);
        strcat(tmp, items[i]);
    }
    
    return tmp;
}