/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 *  NAME
 *      copyback - copy temp or whatever back to /var/mail
 *
 *  SYNOPSIS
 *      void copyback()
 *
 *  DESCRIPTION
 *      Copy the reduced contents of lettmp back to
 *      the mail file. First copy any new mail from
 *      the mail file to the end of lettmp.
 */

#include "mail.h"
void
copyback()
{
        register int    i, n;
        int             new = 0;
        mode_t          mailmode, omask;
        struct stat     stbuf;
        void (*hstat)(), (*istat)(), (*qstat)();

        istat = signal(SIGINT, SIG_IGN);
        qstat = signal(SIGQUIT, SIG_IGN);
        hstat = signal(SIGHUP, SIG_IGN);
        lock(my_name);
        stat(mailfile, &stbuf);
        mailmode = stbuf.st_mode;

        /*
         *      Has new mail arrived?
         */
        if (stbuf.st_size != let[nlet].adr) {
                malf = doopen(mailfile, "r", E_FILE);
                fseek(malf, let[nlet].adr, 0);
                fclose(tmpf);
                tmpf = doopen(lettmp, "a", E_TMP);
                /*
                 *      Append new mail assume only one new letter
                 */
                if (!copystream(malf, tmpf)) {
                        fclose(malf);
                        tmperr();
                        done(0);
                }
                fclose(malf);
                fclose(tmpf);
                tmpf = doopen(lettmp, "r+", E_TMP);
                if (nlet == (MAXLET-2)) {
                        errmsg(E_SPACE, "");
                        done(0);
                }
                let[++nlet].adr = stbuf.st_size;
                new = 1;
        }

        /*
         *      Copy mail back to mail file
         */
        omask = umask(0117);

        /*
         *      The invoker must own the mailfile being copied to
         */
        if ((stbuf.st_uid != my_euid) && (stbuf.st_uid != my_uid)) {
                errmsg(E_OWNR, "");
                done(0);
        }

        /*
         *      If user specified the '-f' option we dont do
         *      the routines to handle :saved files.
         *      As we would(incorrectly) restore to the user's
         *      mailfile upon next execution!
         */
        if (flgf) {
                (void) strlcpy(savefile, mailfile, sizeof (savefile));
        } else {
                cat(savefile, mailsave, my_name);
        }

        if ((malf = fopen(savefile, "w")) == NULL) {
                if (!flgf) {
                        errmsg(E_FILE, "Cannot open savefile");
                } else {
                        errmsg(E_FILE, "Cannot re-write the alternate file");
                }
                done(0);
        }

        if (chown(savefile, mf_uid, mf_gid) == -1) {
                errmsg(E_FILE, "Cannot chown savefile");
                done(0);
        }
        umask(omask);
        n = 0;

        for (i = 0; i < nlet; i++) {
                /*
                 *      Note: any action other than an undelete, or a
                 *      plain read causes the letter acted upon to be
                 *      deleted
                 */
                if (let[i].change == ' ') {
                        if (copylet(i, malf, ORDINARY) == FALSE) {
                                errmsg(E_FILE, "Cannot copy mail to savefile");
                                (void) fprintf(stderr, "%s: A copy of your "
                                    "mailfile is in '%s'\n", program, lettmp);
                                done(1);        /* keep temp file */
                        }
                        n++;
                }
        }
        fclose(malf);

        if (!flgf) {
                if (unlink(mailfile) != 0) {
                        errmsg(E_FILE, "Cannot unlink mailfile");
                        done(0);
                }
                chmod(savefile, mailmode);
#ifdef SVR4
                if (rename(savefile, mailfile) != 0) {
                        errmsg(E_FILE, "Cannot rename savefile to mailfile");
                        done(0);
                }
#else
                if (link(savefile, mailfile) != 0) {
                        errmsg(E_FILE, "Cannot link savefile to mailfile");
                        done(0);
                }
                if (unlink(savefile) != 0) {
                        errmsg(E_FILE, "Cannot unlink save file");
                        done(0);
                }
#endif
        }

        /*
         *      Empty mailbox?
         */
        if (n == 0) {
                delempty(stbuf.st_mode, mailfile);
        }

        if (new && !flgf) {
                printf("New mail arrived\n");
        }

        unlock();
        (void) signal(SIGINT, istat);
        (void) signal(SIGQUIT, qstat);
        (void) signal(SIGHUP, hstat);
}