Date: Wed, 30 Jan 2002 18:16:38 +1100 From: "Tim J. Robbins" <tim@robbins.dropbear.id.au> To: freebsd-standards@FreeBSD.ORG Subject: pwd -L option Message-ID: <20020130181638.A8510@descent.robbins.dropbear.id.au>
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This patch adds the -L option to pwd; most of the source changes were taken
from NetBSD, but adapted so as not to break FreeBSD's realpath utility.
I added an info line in usage() for realpath while I was at it.
It uses the PWD environment variable that sh, ksh93, etc. export and checks
to make sure it "points" to the physical CWD.
Tim
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Index: pwd/pwd.1
===================================================================
RCS file: /home/ncvs/src/bin/pwd/pwd.1,v
retrieving revision 1.15
diff -u -r1.15 pwd.1
--- pwd/pwd.1 2001/08/15 09:09:36 1.15
+++ pwd/pwd.1 2002/01/30 07:18:10
@@ -43,6 +43,7 @@
.Nd return working directory name
.Sh SYNOPSIS
.Nm
+.Op Fl LP
.Sh DESCRIPTION
.Nm Pwd
writes the absolute pathname of the current working directory to
@@ -54,17 +55,28 @@
Consult the
.Xr builtin 1
manual page.
+.Pp
+The options are as follows:
+.Bl -tag -width indent
+.It Fl L
+Display the logical current working directory.
+.It Fl P
+Display the physical current working directory (all symbolic links resolved)
+(default).
.Sh DIAGNOSTICS
.Ex -std
+.Sh ENVIRONMENT
+Environment variables used by
+.Nm :
+.Bl -tag -width PWD
+.It Ev PWD
+Logical current working directory.
.Sh STANDARDS
The
.Nm
utility is expected to be
.St -p1003.2
compatible.
-The
-.Fl L
-flag is not supported.
.Sh SEE ALSO
.Xr builtin 1 ,
.Xr cd 1 ,
@@ -80,3 +92,9 @@
However, it can give a different answer in the rare case
that the current directory or a containing directory was moved after
the shell descended into it.
+.Pp
+The
+.Fl L
+option does not work unless the
+.Ev PWD
+variable is exported by the shell.
Index: pwd/pwd.c
===================================================================
RCS file: /home/ncvs/src/bin/pwd/pwd.c,v
retrieving revision 1.13
diff -u -r1.13 pwd.c
--- pwd/pwd.c 2001/05/30 03:28:29 1.13
+++ pwd/pwd.c 2002/01/30 07:18:11
@@ -45,13 +45,18 @@
"$FreeBSD: src/bin/pwd/pwd.c,v 1.13 2001/05/30 03:28:29 imp Exp $";
#endif /* not lint */
+#include <sys/types.h>
+#include <sys/stat.h>
+
#include <err.h>
+#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/param.h>
+static char *getcwd_logical __P((char *, size_t));
int main __P((int, char *[]));
void usage __P((void));
@@ -63,16 +68,15 @@
int ch;
char *p;
char buf[PATH_MAX];
+ int lflag = 0;
- /*
- * Flags for pwd are a bit strange. The POSIX 1003.2B/D9 document
- * has an optional -P flag for physical, which is what this program
- * will produce by default. The logical flag, -L, should fail, as
- * there's no way to display a logical path after forking.
- */
- while ((ch = getopt(argc, argv, "P")) != -1)
+ while ((ch = getopt(argc, argv, "LP")) != -1)
switch (ch) {
+ case 'L':
+ lflag = 1;
+ break;
case 'P':
+ lflag = 0;
break;
case '?':
default:
@@ -87,7 +91,8 @@
err(1, "%s", argv[0]);
(void)printf("%s\n", p);
} else if (argc == 0) {
- p = getcwd(NULL, (size_t)0);
+ p = lflag ? getcwd_logical(NULL, (size_t)0) :
+ getcwd(NULL, (size_t)0);
if (p == NULL)
err(1, ".");
(void)printf("%s\n", p);
@@ -98,10 +103,51 @@
exit(0);
}
+static char *
+getcwd_logical(char *pt, size_t size)
+{
+ char *pwd;
+ size_t pwdlen;
+ dev_t dev;
+ ino_t ino;
+ struct stat s;
+
+ /* Check $PWD -- if it's right, it's fast. */
+ if ((pwd = getenv("PWD")) != NULL && pwd[0] == '/') {
+ if (stat(pwd, &s) != -1) {
+ dev = s.st_dev;
+ ino = s.st_ino;
+ if (stat(".", &s) != -1 && dev == s.st_dev &&
+ ino == s.st_ino) {
+ pwdlen = strlen(pwd);
+ if (pt) {
+ if (!size) {
+ errno = EINVAL;
+ return (NULL);
+ }
+ if (pwdlen + 1 > size) {
+ errno = ERANGE;
+ return (NULL);
+ }
+ } else if ((pt = malloc(pwdlen + 1)) == NULL)
+ return (NULL);
+ (void)memmove(pt, pwd, pwdlen);
+ pt[pwdlen] = '\0';
+ return (pt);
+ }
+ }
+ } else
+ errno = ENOENT;
+
+ return (NULL);
+}
+
+
void
usage()
{
- (void)fprintf(stderr, "usage: pwd\n");
+ (void)fprintf(stderr, "usage: pwd [-LP]\n");
+ (void)fprintf(stderr, " realpath [file ...]\n");
exit(1);
}
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