usr/othersrc/public/cvs-1.3/src/no_diff.c

/*
 * Copyright (c) 1992, Brian Berliner and Jeff Polk
 * Copyright (c) 1989-1992, Brian Berliner
 *
 * You may distribute under the terms of the GNU General Public License as
 * specified in the README file that comes with the CVS 1.3 kit.
 *
 * No Difference
 *
 * The user file looks modified judging from its time stamp; however it needn't
 * be.  No_difference() finds out whether it is or not. If it is not, it
 * updates the administration.
 *
 * returns 0 if no differences are found and non-zero otherwise
 */

#include "cvs.h"

#ifndef lint
static char rcsid[] = "@(#)no_diff.c 1.35 92/03/31";
#endif

int
No_Difference (file, vers, entries)
    char *file;
    Vers_TS *vers;
    List *entries;
{
    Node *p;
    char tmp[L_tmpnam+1];
    int ret;
    char *ts, *options;
    int retcode = 0;

    if (!vers->srcfile || !vers->srcfile->path)
        return (-1);                    /* different since we couldn't tell */

    if (vers->entdata && vers->entdata->options)
        options = xstrdup (vers->entdata->options);
    else
        options = xstrdup ("");

    run_setup ("%s%s -p -q -r%s %s", Rcsbin, RCS_CO,
               vers->vn_user ? vers->vn_user : "", options);
    run_arg (vers->srcfile->path);
    if ((retcode = run_exec (RUN_TTY, tmpnam (tmp), RUN_TTY, RUN_REALLY)) == 0)
    {
        if (!iswritable (file))         /* fix the modes as a side effect */
            xchmod (file, 1);

        /* do the byte by byte compare */
        if (xcmp (file, tmp) == 0)
        {
            if (cvswrite == FALSE)      /* fix the modes as a side effect */
                xchmod (file, 0);

            /* no difference was found, so fix the entries file */
            ts = time_stamp (file);
            Register (entries, file,
                      vers->vn_user ? vers->vn_user : vers->vn_rcs, ts,
                      options, vers->tag, vers->date);
            free (ts);

            /* update the entdata pointer in the vers_ts structure */
            p = findnode (entries, file);
            vers->entdata = (Entnode *) p->data;

            ret = 0;
        }
        else
            ret = 1;                    /* files were really different */
    }
    else
    {
        error (0, retcode == -1 ? errno : 0,
               "could not check out revision %s of %s", vers->vn_user, file);
        ret = -1;                       /* different since we couldn't tell */
    }

    if (trace)
        (void) fprintf (stderr, "-> unlink(%s)\n", tmp);
    (void) unlink (tmp);
    free (options);
    return (ret);
}