/* $Xorg: lndir.c,v 1.5 2001/02/09 02:03:17 xorgcvs Exp $ */
/* Create shadow link tree (after X11R4 script of the same name)
   Mark Reinhold (mbr@lcs.mit.edu)/3 January 1990 */

/* 
Copyright (c) 1990, 1998 The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from The Open Group.

*/
/* $XFree86: xc/config/util/lndir.c,v 3.18 2003/06/24 15:44:45 eich Exp $ */

/* From the original /bin/sh script:

  Used to create a copy of the a directory tree that has links for all
  non-directories (except, by default, those named BitKeeper, .git, .hg,
  RCS, SCCS, .svn, CVS or CVS.adm).

  If you are building the distribution on more than one machine,
  you should use this technique.

  If your master sources are located in /usr/local/src/X and you would like
  your link tree to be in /usr/local/src/new-X, do the following:

   	%  mkdir /usr/local/src/new-X
	%  cd /usr/local/src/new-X
   	%  lndir ../X
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <X11/Xos.h>
#include <X11/Xfuncproto.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <limits.h>
#include <sys/param.h>
#include <errno.h>
#include <dirent.h>

#ifndef MAXPATHLEN
#define MAXPATHLEN 2048
#endif

#include <stdarg.h>

int silent = 0;			/* -silent */
int ignore_links = 0;		/* -ignorelinks */
int with_revinfo = 0;		/* -withrevinfo */

char *rcurdir;
char *curdir;

static void _X_ATTRIBUTE_PRINTF(2,3) _X_NORETURN
quit (int code, const char * fmt, ...)
{
    va_list args;
    va_start(args, fmt);
    vfprintf (stderr, fmt, args);
    va_end(args);
    putc ('\n', stderr);
    exit (code);
}

static void _X_NORETURN
quiterr (int code, const char *s)
{
    perror (s);
    exit (code);
}

static void _X_ATTRIBUTE_PRINTF(1,2)
msg (const char * fmt, ...)
{
    va_list args;
    if (curdir) {
	fprintf (stderr, "%s:\n", curdir);
	curdir = 0;
    }
    va_start(args, fmt);
    vfprintf (stderr, fmt, args);
    va_end(args);
    putc ('\n', stderr);
}

static void
mperror (char *s)
{
    if (curdir) {
	fprintf (stderr, "%s:\n", curdir);
	curdir = 0;
    }
    perror (s);
}


static int 
equivalent(char *lname, char *rname, char **p)
{
    char *s;

    if (!strcmp(lname, rname))
	return 1;
    for (s = lname; *s && (s = strchr(s, '/')); s++) {
	while (s[1] == '/') {
	    strcpy(s+1, s+2);
	    if (*p) (*p)--;
	}
    }
    return !strcmp(lname, rname);
}


/* Recursively create symbolic links from the current directory to the "from"
   directory.  Assumes that files described by fs and ts are directories. */
static int
dodir (const char *fn,		/* name of "from" directory, either absolute or
				   relative to cwd */
       struct stat *fs, 
       struct stat *ts,		/* stats for the "from" directory and cwd */
       int rel)			/* if true, prepend "../" to fn before using */
{
    DIR *df;
    struct dirent *dp;
    char buf[MAXPATHLEN + 1], *p;
    char symbuf[MAXPATHLEN + 1];
    char basesym[MAXPATHLEN + 1];
    struct stat sb, sc;
    int n_dirs;
    int symlen;
    int basesymlen = -1;
    char *ocurdir;

    if ((fs->st_dev == ts->st_dev) && (fs->st_ino == ts->st_ino)) {
	msg ("%s: From and to directories are identical!", fn);
	return 1;
    }

    if (rel)
	strcpy (buf, "../");
    else
	buf[0] = '\0';
    strcat (buf, fn);
    
    if (!(df = opendir (buf))) {
	msg ("%s: Cannot opendir", buf);
	return 1;
    }

    p = buf + strlen (buf);
    if (*(p - 1) != '/')
	*p++ = '/';
    n_dirs = fs->st_nlink;
    if (n_dirs == 1)
	n_dirs = INT_MAX;
    while ((dp = readdir (df))) {
	if (dp->d_name[strlen(dp->d_name) - 1] == '~')
	    continue;
#ifdef __APPLE__
	/* Ignore these Mac OS X Finder data files */
	if (!strcmp(dp->d_name, ".DS_Store") || 
	    !strcmp(dp->d_name, "._.DS_Store")) 
	    continue;
#endif
	strcpy (p, dp->d_name);

	if (n_dirs > 0) {
	    if (lstat (buf, &sb) < 0) {
		mperror (buf);
		continue;
	    }

	    if (S_ISDIR(sb.st_mode))
	    {
		/* directory */
		n_dirs--;
		if (dp->d_name[0] == '.' &&
		    (dp->d_name[1] == '\0' || (dp->d_name[1] == '.' &&
					       dp->d_name[2] == '\0')))
		    continue;
		if (!with_revinfo) {
		    if (!strcmp (dp->d_name, ".git"))
			continue;
		    if (!strcmp (dp->d_name, ".hg"))
			continue;
		    if (!strcmp (dp->d_name, "BitKeeper"))
			continue;
		    if (!strcmp (dp->d_name, "RCS"))
			continue;
		    if (!strcmp (dp->d_name, "SCCS"))
			continue;
		    if (!strcmp (dp->d_name, "CVS"))
			continue;
		    if (!strcmp (dp->d_name, "CVS.adm"))
			continue;
		    if (!strcmp (dp->d_name, ".svn"))
			continue;
		}
		ocurdir = rcurdir;
		rcurdir = buf;
		curdir = silent ? buf : (char *)0;
		if (!silent)
		    printf ("%s:\n", buf);
		if ((stat (dp->d_name, &sc) < 0) && (errno == ENOENT)) {
		    if (mkdir (dp->d_name, 0777) < 0 ||
			stat (dp->d_name, &sc) < 0) {
			mperror (dp->d_name);
			curdir = rcurdir = ocurdir;
			continue;
		    }
		}
		if (readlink (dp->d_name, symbuf, sizeof(symbuf) - 1) >= 0) {
		    msg ("%s: is a link instead of a directory", dp->d_name);
		    curdir = rcurdir = ocurdir;
		    continue;
		}
		if (chdir (dp->d_name) < 0) {
		    mperror (dp->d_name);
		    curdir = rcurdir = ocurdir;
		    continue;
		}
		dodir (buf, &sb, &sc, (buf[0] != '/'));
		if (chdir ("..") < 0)
		    quiterr (1, "..");
		curdir = rcurdir = ocurdir;
		continue;
	    }
	}

	/* non-directory */
	symlen = readlink (dp->d_name, symbuf, sizeof(symbuf) - 1);
	if (symlen >= 0)
	    symbuf[symlen] = '\0';

	/* The option to ignore links exists mostly because
	   checking for them slows us down by 10-20%.
	   But it is off by default because this really is a useful check. */
	if (!ignore_links) {
	    /* see if the file in the base tree was a symlink */
	    basesymlen = readlink(buf, basesym, sizeof(basesym) - 1);
	    if (basesymlen >= 0)
		basesym[basesymlen] = '\0';
	}

	if (symlen >= 0) {
	    /* Link exists in new tree.  Print message if it doesn't match. */
	    if (!equivalent (basesymlen>=0 ? basesym : buf, symbuf,
			     basesymlen>=0 ? (char **) 0 : &p))
		msg ("%s: %s", dp->d_name, symbuf);
	} else {
	    char *sympath;

	    if (basesymlen>=0) {
		if ((buf[0] == '.') && (buf[1] == '.') && (buf[2] == '/') &&
		    (basesym[0] == '.') && (basesym[1] == '.') &&
		    (basesym[2] == '/')) {
		    /* It becomes very tricky here. We have
		       ../../bar/foo symlinked to ../xxx/yyy. We
		       can't just use ../xxx/yyy. We have to use
		       ../../bar/foo/../xxx/yyy.  */

		    int i;
		    char *start, *end;

		    strcpy (symbuf, buf);
		    /* Find the first char after "../" in symbuf.  */
		    start = symbuf;
		    do {
			start += 3;
		    } while ((start[0] == '.') && (start[1] == '.') &&
			     (start[2] == '/'));

		    /* Then try to eliminate "../"s in basesym.  */
		    i = 0;
		    end = strrchr (symbuf, '/');
		    if (start < end) {
			do {
			    i += 3;
			    end--;
			    while ((*end != '/') && (end != start))
				end--;
			    if (end == start)
				break;
			} while ((basesym[i] == '.') &&
				 (basesym[i + 1] == '.') &&
				 (basesym[i + 2] == '/'));
		    }
		    if (*end == '/')
			end++;
		    strcpy (end, &basesym[i]);
		    sympath = symbuf;
		}
		else
		    sympath = basesym;
	    }
	    else
		sympath = buf;
	    if (symlink (sympath, dp->d_name) < 0)
		mperror (dp->d_name);
	}
    }

    closedir (df);
    return 0;
}

int
main (int argc, char *argv[])
{
    char *prog_name = argv[0];
    const char *fn, *tn;
    struct stat fs, ts;

    while (++argv, --argc) {
	if (strcmp(*argv, "-silent") == 0)
	    silent = 1;
	else if (strcmp(*argv, "-ignorelinks") == 0)
	    ignore_links = 1;
	else if (strcmp(*argv, "-withrevinfo") == 0)
	    with_revinfo = 1;
	else if (strcmp(*argv, "--") == 0) {
	    ++argv, --argc;
	    break;
	}
	else
	    break;
    }

    if (argc < 1 || argc > 2)
	quit (1,
	      "usage: %s [-silent] [-ignorelinks] [-withrevinfo] fromdir [todir]",
	      prog_name);

    fn = argv[0];
    if (argc == 2)
	tn = argv[1];
    else
	tn = ".";

    /* to directory */
    if (stat (tn, &ts) < 0)
	quiterr (1, tn);
    if (!(S_ISDIR(ts.st_mode)))
	quit (2, "%s: Not a directory", tn);
    if (chdir (tn) < 0)
	quiterr (1, tn);

    /* from directory */
    if (stat (fn, &fs) < 0)
	quiterr (1, fn);
    if (!(S_ISDIR(fs.st_mode)))
	quit (2, "%s: Not a directory", fn);

    exit (dodir (fn, &fs, &ts, 0));
}