Logo Search packages:      
Sourcecode: dash version File versions

cd.c

/*    $NetBSD: cd.c,v 1.30 2003/01/22 20:36:03 dsl Exp $    */

/*-
 * Copyright (c) 1991, 1993
 *    The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by the University of
 *    California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)cd.c    8.2 (Berkeley) 5/4/95";
#else
__RCSID("$NetBSD: cd.c,v 1.30 2003/01/22 20:36:03 dsl Exp $");
#endif
#endif /* not lint */

#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

/*
 * The cd and pwd commands.
 */

#include "shell.h"
#include "var.h"
#include "nodes.h"      /* for jobs.h */
#include "jobs.h"
#include "options.h"
#include "output.h"
#include "memalloc.h"
#include "error.h"
#include "exec.h"
#include "redir.h"
#include "mystring.h"
#include "show.h"
#include "cd.h"

#define CD_PHYSICAL 1
#define CD_PRINT 2

STATIC int docd(const char *, int);
STATIC const char *updatepwd(const char *);
STATIC char *getpwd(void);
STATIC int cdopt(void);

STATIC char *curdir = nullstr;            /* current working directory */
STATIC char *physdir = nullstr;           /* physical working directory */

STATIC int
cdopt()
{
      int flags = 0;
      int i, j;

      j = 'L';
      while ((i = nextopt("LP"))) {
            if (i != j) {
                  flags ^= CD_PHYSICAL;
                  j = i;
            }
      }

      return flags;
}

int
cdcmd(int argc, char **argv)
{
      const char *dest;
      const char *path;
      const char *p;
      char c;
      struct stat statb;
      int flags;

      flags = cdopt();
      dest = *argptr;
      if (!dest)
            dest = bltinlookup(homestr);
      else if (dest[0] == '-' && dest[1] == '\0') {
            dest = bltinlookup("OLDPWD");
            flags |= CD_PRINT;
      }
      if (!dest)
            dest = nullstr;
      if (*dest == '/')
            goto step7;
      if (*dest == '.') {
            c = dest[1];
dotdot:
            switch (c) {
            case '\0':
            case '/':
                  goto step6;
            case '.':
                  c = dest[2];
                  if (c != '.')
                        goto dotdot;
            }
      }
      if (!*dest)
            dest = ".";
      if (!(path = bltinlookup("CDPATH"))) {
step6:
step7:
            p = dest;
            goto docd;
      }
      do {
            c = *path;
            p = padvance(&path, dest);
            if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) {
                  if (c && c != ':')
                        flags |= CD_PRINT;
docd:
                  if (!docd(p, flags))
                        goto out;
                  break;
            }
      } while (path);
      error("can't cd to %s", dest);
      /* NOTREACHED */
out:
      if (flags & CD_PRINT)
            out1fmt(snlfmt, curdir);
      return 0;
}


/*
 * Actually do the chdir.  We also call hashcd to let the routines in exec.c
 * know that the current directory has changed.
 */

STATIC int
docd(const char *dest, int flags)
{
      const char *dir = 0;
      int err;

      TRACE(("docd(\"%s\", %d) called\n", dest, flags));

      INTOFF;
      if (!(flags & CD_PHYSICAL)) {
            dir = updatepwd(dest);
            if (dir)
                  dest = dir;
      }
      err = chdir(dest);
      if (err)
            goto out;
      setpwd(dir, 1);
      hashcd();
out:
      INTON;
      return err;
}


/*
 * Update curdir (the name of the current directory) in response to a
 * cd command.
 */

STATIC const char *
updatepwd(const char *dir)
{
      char *new;
      char *p;
      char *cdcomppath;
      const char *lim;

      cdcomppath = sstrdup(dir);
      STARTSTACKSTR(new);
      if (*dir != '/') {
            if (curdir == nullstr)
                  return 0;
            new = stputs(curdir, new);
      }
      new = makestrspace(strlen(dir) + 2, new);
      lim = stackblock() + 1;
      if (*dir != '/') {
            if (new[-1] != '/')
                  USTPUTC('/', new);
            if (new > lim && *lim == '/')
                  lim++;
      } else {
            USTPUTC('/', new);
            cdcomppath++;
            if (dir[1] == '/' && dir[2] != '/') {
                  USTPUTC('/', new);
                  cdcomppath++;
                  lim++;
            }
      }
      p = strtok(cdcomppath, "/");
      while (p) {
            switch(*p) {
            case '.':
                  if (p[1] == '.' && p[2] == '\0') {
                        while (new > lim) {
                              STUNPUTC(new);
                              if (new[-1] == '/')
                                    break;
                        }
                        break;
                  } else if (p[1] == '\0')
                        break;
                  /* fall through */
            default:
                  new = stputs(p, new);
                  USTPUTC('/', new);
            }
            p = strtok(0, "/");
      }
      if (new > lim)
            STUNPUTC(new);
      *new = 0;
      return stackblock();
}


#define MAXPWD 256

/*
 * Find out what the current directory is. If we already know the current
 * directory, this routine returns immediately.
 */
inline
STATIC char *
getpwd()
{
      char *dir = getcwd(0, 0);
      return dir ? dir : nullstr;
}

int
pwdcmd(int argc, char **argv)
{
      int flags;
      const char *dir = curdir;

      flags = cdopt();
      if (flags) {
            if (physdir == nullstr)
                  setpwd(dir, 0);
            dir = physdir;
      }
      out1fmt(snlfmt, dir);
      return 0;
}

void
setpwd(const char *val, int setold)
{
      char *oldcur, *dir;

      oldcur = dir = curdir;

      if (setold) {
            setvar("OLDPWD", oldcur, VEXPORT);
      }
      INTOFF;
      if (physdir != nullstr) {
            if (physdir != oldcur)
                  free(physdir);
            physdir = nullstr;
      }
      if (oldcur == val || !val) {
            char *s = getpwd();
            physdir = s;
            if (!val)
                  dir = s;
      } else
            dir = savestr(val);
      if (oldcur != dir && oldcur != nullstr) {
            free(oldcur);
      }
      curdir = dir;
      INTON;
      setvar("PWD", dir, VEXPORT);
}

Generated by  Doxygen 1.6.0   Back to index