fg_string.c

Go to the documentation of this file.

 
/*
 * Copyright (C) 2014 Alexander Zimmermann <alexander.zimmermann@netapp.com>
 *
 * This file is part of Flowgrind.
 *
 * Flowgrind is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Flowgrind is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Flowgrind.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */
 
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
 
#include "fg_string.h"
#include "fg_definitions.h"
 
static inline char *strlendup_append(char *s, size_t slen, const char *a,
                                     size_t alen)
{
        char *ret = realloc(s, slen + alen + 1);
        if (unlikely(!ret))
                return NULL;
 
        /* append the string and the trailing \0 */
        memcpy(&ret[slen], a, alen);
        ret[slen+alen] = 0;
 
        return ret;
}
 
size_t fmtlen(const char *fmt, va_list ap)
{
        va_list ap2;
        char c;
 
        /* If the output of vsnprintf is truncated, its return value is the
         * number of characters which would have been written to the string
         * if enough space had been available */
        va_copy(ap2, ap);
        size_t length = vsnprintf(&c, 1, fmt, ap2);
        va_end(ap2);
 
        return length;
}
 
char *strdup_append(char *s, const char *a)
{
        if (unlikely(!s))
                return strdup(a);
 
        if (unlikely(!a))
                return s;
 
        return strlendup_append(s, strlen(s), a, strlen(a));
}
 
char *strndup_append(char *s, const char *a, size_t n)
{
        if (unlikely(!s))
                return strdup(a);
 
        if (unlikely(!a))
                return s;
 
        return strlendup_append(s, strlen(s), a, strnlen(a, n));
}
 
int asprintf_append(char **strp, const char *fmt, ...)
{
        va_list ap;
 
        va_start(ap, fmt);
        size_t length = vasprintf_append(strp, fmt, ap);
        va_end(ap);
 
        return length;
}
 
int vasprintf_append(char **strp, const char *fmt, va_list ap)
{
        if (unlikely(!(*strp)))
                return vasprintf(strp, fmt, ap);
 
        size_t slen = strlen(*strp);
        size_t alen = fmtlen(fmt, ap);
 
        /* The format resulted in no characters being formatted */
        if (unlikely(alen == 0))
                return -1;
 
        char *new_strp = realloc(*strp, slen + alen + 1);
        if (unlikely(!(*new_strp)))
                return -1;
 
        *strp = new_strp;
 
        va_list ap2;
        va_copy(ap2, ap);
        size_t length = vsnprintf(*strp + slen, alen + 1, fmt, ap2);
        va_end(ap2);
 
        return length;
}