Add a -P/-o physical option which behaves similarly to bash/ksh's options

by the same name. This option makes the cd and pwd builtins behave physically
(as opposed to logically) by default.

Submitted by:	fanf

bin/sh/cd.c

@@ -88,7 +88,7 @@ cdcmd(int argc, char **argv)
 	int ch, phys, print = 0;
 
 	optreset = 1; optind = 1; opterr = 0; /* initialize getopt */
-	phys = 0;
+	phys = Pflag;
 	while ((ch = getopt(argc, argv, "LP")) != -1) {
 		switch (ch) {
 		case 'L':
@@ -324,7 +324,7 @@ pwdcmd(int argc, char **argv)
 	int ch, phys;
 
 	optreset = 1; optind = 1; opterr = 0; /* initialize getopt */
-	phys = 0;
+	phys = Pflag;
 	while ((ch = getopt(argc, argv, "LP")) != -1) {
 		switch (ch) {
 		case 'L':

bin/sh/options.h

@@ -65,8 +65,9 @@ struct shparam {
 #define	uflag optlist[14].val
 #define	privileged optlist[15].val
 #define	Tflag optlist[16].val
+#define	Pflag optlist[17].val
 
-#define NOPTS	17
+#define NOPTS	18
 
 struct optent {
 	const char *name;
@@ -93,6 +94,7 @@ struct optent optlist[NOPTS] = {
 	{ "nounset",	'u',	0 },
 	{ "privileged",	'p',	0 },
 	{ "trapsasync",	'T',	0 },
+	{ "physical",	'P',	0 },
 };
 #else
 extern struct optent optlist[NOPTS];

bin/sh/sh.1

@@ -43,7 +43,7 @@
 .Nd command interpreter (shell)
 .Sh SYNOPSIS
 .Nm
-.Op Fl /+abCEefIimnpsTuVvx
+.Op Fl /+abCEefIimnPpsTuVvx
 .Op Fl /+o Ar longname
 .Op Fl c Ar string
 .Op Ar arg ...
@@ -225,6 +225,17 @@ Turn on job control (set automatically when interactive).
 If not interactive, read commands but do not
 execute them.  This is useful for checking the
 syntax of shell scripts.
+.It Fl P Li physical
+Change the default for the
+.Ic cd
+and
+.Ic pwd
+commands from
+.Fl L
+(logical directory layout)
+to
+.Fl P
+(physical directory layout).
 .It Fl p Li privileged
 Turn on privileged mode.  This mode is enabled on startup
 if either the effective user or group id is not equal to the