1 files changed, 372 insertions, 0 deletions
diff --git a/bin/sh/cd.c b/bin/sh/cd.c
new file mode 100644
index 000000000000..d1984d9fb111
--- /dev/null
+++ b/bin/sh/cd.c
@@ -0,0 +1,372 @@
+/*-
+ * 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.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)cd.c	8.1 (Berkeley) 5/31/93";
+#endif /* not lint */
+
+/*
+ * 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 "mystring.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+
+#ifdef __STDC__
+STATIC int docd(char *, int);
+STATIC void updatepwd(char *);
+STATIC void getpwd(void);
+STATIC char *getcomponent(void);
+#else
+STATIC int docd();
+STATIC void updatepwd();
+STATIC void getpwd();
+STATIC char *getcomponent();
+#endif
+
+
+char *curdir;			/* current working directory */
+char *prevdir;			/* previous working directory */
+STATIC char *cdcomppath;
+
+int
+cdcmd(argc, argv)  char **argv; {
+	char *dest;
+	char *path;
+	char *p;
+	struct stat statb;
+	char *padvance();
+	int print = 0;
+
+	nextopt(nullstr);
+	if ((dest = *argptr) == NULL && (dest = bltinlookup("HOME", 1)) == NULL)
+		error("HOME not set");
+	if (dest[0] == '-' && dest[1] == '\0') {
+		dest = prevdir ? prevdir : curdir;
+		print = 1;
+	}
+	if (*dest == '/' || (path = bltinlookup("CDPATH", 1)) == NULL)
+		path = nullstr;
+	while ((p = padvance(&path, dest)) != NULL) {
+		if (stat(p, &statb) >= 0
+		 && (statb.st_mode & S_IFMT) == S_IFDIR) {
+			if (!print) {
+				/*
+				 * XXX - rethink
+				 */
+				if (p[0] == '.' && p[1] == '/')
+					p += 2;
+				print = strcmp(p, dest);
+			}
+			if (docd(p, print) >= 0)
+				return 0;
+
+		}
+	}
+	error("can't cd to %s", dest);
+}
+
+
+/*
+ * Actually do the chdir.  If the name refers to symbolic links, we
+ * compute the actual directory name before doing the cd.  In an
+ * interactive shell, print the directory name if "print" is nonzero
+ * or if the name refers to a symbolic link.  We also print the name
+ * if "/u/logname" was expanded in it, since this is similar to a
+ * symbolic link.  (The check for this breaks if the user gives the
+ * cd command some additional, unused arguments.)
+ */
+
+#if SYMLINKS == 0
+STATIC int
+docd(dest, print)
+	char *dest;
+	{
+	INTOFF;
+	if (chdir(dest) < 0) {
+		INTON;
+		return -1;
+	}
+	updatepwd(dest);
+	INTON;
+	if (print && iflag)
+		out1fmt("%s\n", stackblock());
+	return 0;
+}
+
+#else
+
+
+
+STATIC int
+docd(dest, print)
+	char *dest;
+	{
+	register char *p;
+	register char *q;
+	char *symlink;
+	char *component;
+	struct stat statb;
+	int first;
+	int i;
+
+	TRACE(("docd(\"%s\", %d) called\n", dest, print));
+
+top:
+	cdcomppath = dest;
+	STARTSTACKSTR(p);
+	if (*dest == '/') {
+		STPUTC('/', p);
+		cdcomppath++;
+	}
+	first = 1;
+	while ((q = getcomponent()) != NULL) {
+		if (q[0] == '\0' || q[0] == '.' && q[1] == '\0')
+			continue;
+		if (! first)
+			STPUTC('/', p);
+		first = 0;
+		component = q;
+		while (*q)
+			STPUTC(*q++, p);
+		if (equal(component, ".."))
+			continue;
+		STACKSTRNUL(p);
+		if (lstat(stackblock(), &statb) < 0)
+			error("lstat %s failed", stackblock());
+		if ((statb.st_mode & S_IFMT) != S_IFLNK)
+			continue;
+
+		/* Hit a symbolic link.  We have to start all over again. */
+		print = 1;
+		STPUTC('\0', p);
+		symlink = grabstackstr(p);
+		i = (int)statb.st_size + 2;		/* 2 for '/' and '\0' */
+		if (cdcomppath != NULL)
+			i += strlen(cdcomppath);
+		p = stalloc(i);
+		if (readlink(symlink, p, (int)statb.st_size) < 0) {
+			error("readlink %s failed", stackblock());
+		}
+		if (cdcomppath != NULL) {
+			p[(int)statb.st_size] = '/';
+			scopy(cdcomppath, p + (int)statb.st_size + 1);
+		} else {
+			p[(int)statb.st_size] = '\0';
+		}
+		if (p[0] != '/') {	/* relative path name */
+			char *r;
+			q = r = symlink;
+			while (*q) {
+				if (*q++ == '/')
+					r = q;
+			}
+			*r = '\0';
+			dest = stalloc(strlen(symlink) + strlen(p) + 1);
+			scopy(symlink, dest);
+			strcat(dest, p);
+		} else {
+			dest = p;
+		}
+		goto top;
+	}
+	STPUTC('\0', p);
+	p = grabstackstr(p);
+	INTOFF;
+	if (chdir(p) < 0) {
+		INTON;
+		return -1;
+	}
+	updatepwd(p);
+	INTON;
+	if (print && iflag)
+		out1fmt("%s\n", p);
+	return 0;
+}
+#endif /* SYMLINKS */
+
+
+
+/*
+ * Get the next component of the path name pointed to by cdcomppath.
+ * This routine overwrites the string pointed to by cdcomppath.
+ */
+
+STATIC char *
+getcomponent() {
+	register char *p;
+	char *start;
+
+	if ((p = cdcomppath) == NULL)
+		return NULL;
+	start = cdcomppath;
+	while (*p != '/' && *p != '\0')
+		p++;
+	if (*p == '\0') {
+		cdcomppath = NULL;
+	} else {
+		*p++ = '\0';
+		cdcomppath = p;
+	}
+	return start;
+}
+
+
+
+/*
+ * Update curdir (the name of the current directory) in response to a
+ * cd command.  We also call hashcd to let the routines in exec.c know
+ * that the current directory has changed.
+ */
+
+void hashcd();
+
+STATIC void
+updatepwd(dir)
+	char *dir;
+	{
+	char *new;
+	char *p;
+
+	hashcd();				/* update command hash table */
+	cdcomppath = stalloc(strlen(dir) + 1);
+	scopy(dir, cdcomppath);
+	STARTSTACKSTR(new);
+	if (*dir != '/') {
+		if (curdir == NULL)
+			return;
+		p = curdir;
+		while (*p)
+			STPUTC(*p++, new);
+		if (p[-1] == '/')
+			STUNPUTC(new);
+	}
+	while ((p = getcomponent()) != NULL) {
+		if (equal(p, "..")) {
+			while (new > stackblock() && (STUNPUTC(new), *new) != '/');
+		} else if (*p != '\0' && ! equal(p, ".")) {
+			STPUTC('/', new);
+			while (*p)
+				STPUTC(*p++, new);
+		}
+	}
+	if (new == stackblock())
+		STPUTC('/', new);
+	STACKSTRNUL(new);
+	INTOFF;
+	if (prevdir)
+		ckfree(prevdir);
+	prevdir = curdir;
+	curdir = savestr(stackblock());
+	INTON;
+}
+
+
+
+int
+pwdcmd(argc, argv)  char **argv; {
+	getpwd();
+	out1str(curdir);
+	out1c('\n');
+	return 0;
+}
+
+
+
+/*
+ * Run /bin/pwd to find out what the current directory is.  We suppress
+ * interrupts throughout most of this, but the user can still break out
+ * of it by killing the pwd program.  If we already know the current
+ * directory, this routine returns immediately.
+ */
+
+#define MAXPWD 256
+
+STATIC void
+getpwd() {
+	char buf[MAXPWD];
+	char *p;
+	int i;
+	int status;
+	struct job *jp;
+	int pip[2];
+
+	if (curdir)
+		return;
+	INTOFF;
+	if (pipe(pip) < 0)
+		error("Pipe call failed");
+	jp = makejob((union node *)NULL, 1);
+	if (forkshell(jp, (union node *)NULL, FORK_NOJOB) == 0) {
+		close(pip[0]);
+		if (pip[1] != 1) {
+			close(1);
+			copyfd(pip[1], 1);
+			close(pip[1]);
+		}
+		execl("/bin/pwd", "pwd", (char *)0);
+		error("Cannot exec /bin/pwd");
+	}
+	close(pip[1]);
+	pip[1] = -1;
+	p = buf;
+	while ((i = read(pip[0], p, buf + MAXPWD - p)) > 0
+	     || i == -1 && errno == EINTR) {
+		if (i > 0)
+			p += i;
+	}
+	close(pip[0]);
+	pip[0] = -1;
+	status = waitforjob(jp);
+	if (status != 0)
+		error((char *)0);
+	if (i < 0 || p == buf || p[-1] != '\n')
+		error("pwd command failed");
+	p[-1] = '\0';
+	curdir = savestr(buf);
+	INTON;
+}