libcruft-util/paths_posix.cpp

/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Copyright 2020, Danny Robson <danny@nerdcruft.net>
 */

#include "paths.hpp"

#include "posix/except.hpp"
#include "debug/assert.hpp"

#include <memory>

#include <wordexp.h>


///////////////////////////////////////////////////////////////////////////////
std::filesystem::path
cruft::paths::temp (void)
{
    if (char const *tmpdir = getenv ("TMPDIR"); tmpdir)
        return tmpdir;

    return "/tmp";
}


///////////////////////////////////////////////////////////////////////////////
std::filesystem::path
cruft::paths::expand (std::filesystem::path const &val)
{
    wordexp_t words;
    posix::error::try_call (wordexp, val.c_str (), &words, WRDE_NOCMD | WRDE_UNDEF);
    std::unique_ptr<wordexp_t, decltype(&wordfree)> cleanup {&words, &wordfree};

    if (words.we_wordc != 1)
        throw std::runtime_error ("path expansion is not singular");

    CHECK_EQ (words.we_offs, 0u);
    return words.we_wordv[0];
}