cmd/mail/cksaved.c

/*
 * 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
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/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 *  NAME
 *  cksaved - check for an orphaned save file
 *
 *  SYNOPSIS
 *  void cksaved(char *user)
 *
 *  DESCRIPTION
 *  cksaved() looks to see if there is a saved-mail file sitting
 *  around which should be reinstated. These files should be sitting
 *  around only in the case of a crash during rewriting a mail message.
 *
 *  The strategy is simple: if the file exists it is appended to
 *  the end of $MAIL.  It is better that a user potentially sees the
 *  mail twice than to lose it.
 *
 *  If $MAIL doesn't exist, then a simple rename() will suffice.
 */

#include "mail.h"
void
cksaved(user)
char    *user;
{
    struct stat stbuf;
    char command[512];
    char save[MAXFILENAME], mail[MAXFILENAME];

    cat(mail, maildir, user);
    cat(save, mailsave, user);

    /*
     *  If no save file, or size is 0, return.
     */
    if ((stat(save, &stbuf) != 0) || (stbuf.st_size == 0))
        return;

    /*
     *  Ok, we have a savefile. If no mailfile exists,
     *  then we want to restore to the mailfile,
     *  else we append to the mailfile.
     */
    lock(user);
    if (stat(mail, &stbuf) != 0) {
        /*
         *  Restore from the save file by linking
         *  it to $MAIL then unlinking save file
         */
        chmod(save, MFMODE);
#ifdef SVR3
        if (link(save, mail) != 0) {
            unlock();
            perror("Restore failed to link to mailfile");
            return;
        }

        if (unlink(save) != 0) {
            unlock();
            perror("Cannot unlink saved file");
            return;
        }
#else
        if (rename(save, mail) != 0) {
            unlock();
            perror("Cannot rename saved file");
            return;
        }
#endif

        (void) snprintf(command, sizeof (command),
            "echo \"Your mailfile was just restored by the mail "
            "program.\nPermissions of your mailfile are set "
            "to 0660.\"| mail %s", user);
    }

    else {
        FILE *Istream, *Ostream;
        if ((Ostream = fopen(mail, "a")) == NULL) {
            (void) fprintf(stderr,
                "%s: Cannot open file '%s' for output\n",
            program, mail);
            unlock();
            return;
        }
        if ((Istream = fopen(save, "r")) == NULL) {
            (void) fprintf(stderr, "%s: Cannot open saved "
                "file '%s' for reading\n", program, save);
            fclose(Ostream);
            unlock();
            return;
        }
        copystream(Istream, Ostream);
        fclose(Istream);
        fclose(Ostream);

        if (unlink(save) != 0) {
            perror("Unlink of save file failed");
            return;
        }

        (void) snprintf(command, sizeof (command),
            "echo \"Your mail save file has just been appended "
            "to your mail box by the mail program.\" | mail %s", user);
    }

    /*
     *  Try to send mail to the user whose file
     *  is being restored.
     */
    unlock();
    systm(command);
}