custr.c revision 196c7f05d2deba7404e90ad67f3861185c78ca2d
/*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*/
/*
* String utility functions with dynamic memory management.
*/
/*
* Copyright 2014, Joyent, Inc.
*/
#include <stdlib.h>
#include <err.h>
#include <string.h>
#include "libcmdutils.h"
struct custr {
size_t cus_strlen;
size_t cus_datalen;
char *cus_data;
};
#define STRING_CHUNK_SIZE 64
void
custr_reset(custr_t *cus)
{
if (cus->cus_data == NULL)
return;
cus->cus_strlen = 0;
cus->cus_data[0] = '\0';
}
size_t
custr_len(custr_t *cus)
{
return (cus->cus_strlen);
}
const char *
custr_cstr(custr_t *cus)
{
return (cus->cus_data);
}
int
custr_appendc(custr_t *cus, char newc)
{
char news[2];
news[0] = newc;
news[1] = '\0';
return (custr_append(cus, news));
}
int
custr_append(custr_t *cus, const char *news)
{
size_t len = strlen(news);
size_t chunksz = STRING_CHUNK_SIZE;
while (chunksz < len) {
chunksz *= 2;
}
if (len + cus->cus_strlen + 1 >= cus->cus_datalen) {
char *new_data;
size_t new_datalen = cus->cus_datalen + chunksz;
/*
* Allocate replacement memory:
*/
if ((new_data = malloc(new_datalen)) == NULL) {
return (-1);
}
/*
* Copy existing data into replacement memory and free
* the old memory.
*/
if (cus->cus_data != NULL) {
(void) memcpy(new_data, cus->cus_data,
cus->cus_strlen + 1);
free(cus->cus_data);
}
/*
* Swap in the replacement buffer:
*/
cus->cus_data = new_data;
cus->cus_datalen = new_datalen;
}
/*
* Append new string to existing string:
*/
(void) memcpy(cus->cus_data + cus->cus_strlen, news, len + 1);
cus->cus_strlen += len;
return (0);
}
int
custr_alloc(custr_t **cus)
{
custr_t *t;
if ((t = calloc(1, sizeof (*t))) == NULL) {
*cus = NULL;
return (-1);
}
*cus = t;
return (0);
}
void
custr_free(custr_t *cus)
{
if (cus == NULL)
return;
free(cus->cus_data);
free(cus);
}