Return to fs.c CVS log

Up to [Coherent Logic Development] / freem / src

First phase of REUSE compliance and header reformat

/*
 *   $Id: fs.c,v 1.3 2025/03/09 19:14:25 snw Exp $
 *    filesystem support functions
 *
 *  
 *   Author: Serena Willis <snw@coherent-logic.com>
 *    Copyright (C) 1998 MUG Deutschland
 *    Copyright (C) 2024, 2025 Coherent Logic Development LLC
 *
 *
 *   This file is part of FreeM.
 *
 *   FreeM is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU Affero Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   FreeM 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 Affero Public License for more details.
 *
 *   You should have received a copy of the GNU Affero Public License
 *   along with FreeM.  If not, see <https://www.gnu.org/licenses/>.
 *
 *   $Log: fs.c,v $
 *   Revision 1.3  2025/03/09 19:14:25  snw
 *   First phase of REUSE compliance and header reformat
 *
 *
 * SPDX-FileCopyrightText:  (C) 2025 Coherent Logic Development LLC
 * SPDX-License-Identifier: AGPL-3.0-or-later
 **/

#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include "fs.h"

int cp(const char *to, const char *from)
{
    int fd_to, fd_from;
    char buf[4096];
    ssize_t nread;
    int saved_errno;

    fd_from = open(from, O_RDONLY);
    if (fd_from < 0)
        return -1;

    fd_to = open(to, O_WRONLY | O_CREAT | O_EXCL, 0666);
    if (fd_to < 0)
        goto out_error;

    while (nread = read(fd_from, buf, sizeof buf), nread > 0)
    {
        char *out_ptr = buf;
        ssize_t nwritten;

        do {
            nwritten = write(fd_to, out_ptr, nread);

            if (nwritten >= 0)
            {
                nread -= nwritten;
                out_ptr += nwritten;
            }
            else if (errno != EINTR)
            {
                goto out_error;
            }
        } while (nread > 0);
    }

    if (nread == 0)
    {
        if (close(fd_to) < 0)
        {
            fd_to = -1;
            goto out_error;
        }
        close(fd_from);

        /* Success! */
        return 0;
    }

  out_error:
    saved_errno = errno;

    close(fd_from);
    if (fd_to >= 0)
        close(fd_to);

    errno = saved_errno;
    return -1;
}