encfs/encfs/autosprintf.cpp
2017-08-03 22:46:34 -07:00

69 lines
2.2 KiB
C++

/* 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 "autosprintf.h"
#include <cstdarg> // for va_list
#include <cstdio> // for NULL, vasprintf
#include <cstdlib> // for free
#include <cstring> // for strdup
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 = nullptr;
}
va_end(args);
}
/* Copy constructor. Necessary because the destructor is nontrivial. */
autosprintf::autosprintf(const autosprintf &src) {
str = (src.str != nullptr ? strdup(src.str) : nullptr);
}
/* Destructor: frees the temporarily allocated string. */
autosprintf::~autosprintf() { free(str); }
/* Conversion to string. */
autosprintf::operator char *() const {
if (str != nullptr) {
size_t length = strlen(str) + 1;
auto *copy = new char[length];
memcpy(copy, str, length);
return copy;
}
return nullptr;
}
autosprintf::operator std::string() const {
return std::string(str != nullptr ? str : "(error in autosprintf)");
}
} // namespace gnu