encfs/base/autosprintf.cpp

/* Class autosprintf - formatted output to an ostream.
   Copyright (C) 2002 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2002.

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU Library General Public License as published
   by the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
   USA.  */

/* Tell glibc's <stdio.h> to provide a prototype for vasprintf().
   This must come before <config.h> because <config.h> may include
   <features.h>, and once <features.h> has been included, it's too late.  */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif

/* Specification.  */
#include "base/autosprintf.h"

#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
//#include "lib-asprintf.h"
#include <stdio.h>

namespace gnu {

/* Constructor: takes a format string and the printf arguments.  */
autosprintf::autosprintf(const char *format, ...) {
  va_list args;
  va_start(args, format);
  if (vasprintf(&str, format, args) < 0) str = NULL;
  va_end(args);
}

/* Copy constructor.  Necessary because the destructor is nontrivial.  */
autosprintf::autosprintf(const autosprintf &src) {
  str = (src.str != NULL ? strdup(src.str) : NULL);
}

/* Destructor: frees the temporarily allocated string.  */
autosprintf::~autosprintf() { free(str); }

/* Conversion to string.  */
autosprintf::operator char *() const {
  if (str != NULL) {
    size_t length = strlen(str) + 1;
    char *copy = new char[length];
    memcpy(copy, str, length);
    return copy;
  } else
    return NULL;
}
autosprintf::operator std::string() const {
  return std::string(str ? str : "(error in autosprintf)");
}
}