gstr.c

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

#include "gstr.h"

#define GROW_BY 128

GSTR *gstr_new(char *d) {
    GSTR *g = (GSTR *) malloc(sizeof(GSTR));
    g->size = 0;
    g->len = 0;
    g->buf = NULL;
    gstr_append(g, d);
    return g;
}

void gstr_appendn(GSTR *g, char *b, size_t len) {
    if (!b)
        return;
    if (!g->buf) {
        g->buf = malloc(len);
        g->size = len;
        g->len = len;
        strncpy(g->buf, b, len);
    } else {
        if (g->size < g->len + len + 1) {
            g->buf = realloc(g->buf, (g->size = g->len + len + GROW_BY));
        }
        strncpy(g->buf + g->len, b, len);
        g->len += len;
    }
}

void gstr_append(GSTR *g, char *d) {
    size_t len;
    if (!d)
        return;
    len = strlen(d);
    if (!g->buf) {
        g->buf = strdup(d);
        g->size = len + 1;
        g->len = len;
    } else {
        if (g->size < g->len + len + 1) {
            g->buf = realloc(g->buf, (g->size = g->len + len + GROW_BY));
        }
        strcpy(g->buf + g->len, d);
        g->len += len;
    }
}

void gstr_appendc(GSTR *g, char c) {
    char cs[2];
    cs[0] = c;
    cs[1] = '\0';
    gstr_append(g, cs);
}

char *gstr_detach(GSTR *g) {
    char *result;
    result = realloc(g->buf, g->len + 1);
    free(g);
    return result;
}

char *gstr_cat(char *a, char *b) {
    GSTR *g = gstr_new(a);
    gstr_append(g, b);
    return gstr_detach(g);
}

/* concatenate and free */
char *gstr_catf(char *a, char *b) {
    GSTR *g = gstr_new(a);
    gstr_append(g, b);
    return gstr_detach(g);
    free(a);
    free(b);
}