Implement the P1003.2 `command' builtin command, which is used to suppress

shell function and alias lookup. The -p option has been implemented, the
UPE -v and -V options have not. The old `command' command has been renamed
to `builtin'.

bin/sh/builtins.def

@@ -49,7 +49,8 @@
 #
 # NOTE: bltincmd must come first!
 
-bltincmd	command
+bltincmd	builtin
+commandcmd	command
 #alloccmd	alloc
 bgcmd -j	bg
 breakcmd	break continue

bin/sh/eval.c

@@ -42,6 +42,7 @@ static char sccsid[] = "@(#)eval.c	8.9 (Berkeley) 6/8/95";
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include <paths.h>
 #include <signal.h>
 #include <unistd.h>
 #include <sys/wait.h> /* For WIFSIGNALED(status) */
@@ -747,7 +748,9 @@ evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
 	    && (cmdentry.cmdtype != CMDBUILTIN
 		 || cmdentry.u.index == CDCMD
 		 || cmdentry.u.index == DOTCMD
-		 || cmdentry.u.index == EVALCMD))) {
+		 || cmdentry.u.index == EVALCMD))
+	 || (cmdentry.cmdtype == CMDBUILTIN &&
+	    cmdentry.u.index == COMMANDCMD)) {
 		jp = makejob(cmd, 1);
 		mode = cmd->ncmd.backgnd;
 		if (flags & EV_BACKCMD) {
@@ -869,7 +872,8 @@ evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
 #ifndef NO_HISTORY
 			   || cmdentry.u.index == HISTCMD
 #endif
-			   || cmdentry.u.index == EXECCMD)
+			   || cmdentry.u.index == EXECCMD
+			   || cmdentry.u.index == COMMANDCMD)
 				exraise(e);
 			FORCEINTON;
 		}
@@ -986,6 +990,54 @@ breakcmd(int argc, char **argv)
 	return 0;
 }
 
+/*
+ * The `command' command.
+ */
+int
+commandcmd(int argc, char **argv)
+{
+	static char stdpath[] = _PATH_STDPATH;
+	struct jmploc loc, *old;
+	struct strlist *sp;
+	char *path;
+	int ch;
+
+	for (sp = cmdenviron; sp ; sp = sp->next)
+		setvareq(sp->text, VEXPORT|VSTACK);
+	path = pathval();
+
+	optind = optreset = 1;
+	while ((ch = getopt(argc, argv, "p")) != -1) {
+		switch (ch) {
+		case 'p':
+			path = stdpath;
+			break;
+		case '?':
+		default:
+			error("unknown option: -%c", optopt);
+		}
+	}
+	argc -= optind;
+	argv += optind;
+
+	if (argc != 0) {
+		old = handler;
+		handler = &loc;
+		if (setjmp(handler->loc) == 0)
+			shellexec(argv, environment(), path, 0);
+		handler = old;
+		if (exception == EXEXEC)
+			exit(exerrno);
+		exraise(exception);
+	}
+
+	/*
+	 * Do nothing successfully if no command was specified;
+	 * ksh also does this.
+	 */
+	exit(0);
+}
+
 
 /*
  * The return command.

bin/sh/eval.h

@@ -60,6 +60,7 @@ int returncmd(int, char **);
 int falsecmd(int, char **);
 int truecmd(int, char **);
 int execcmd(int, char **);
+int commandcmd(int, char **);
 
 /* in_function returns nonzero if we are currently evaluating a function */
 #define in_function()	funcnest

bin/sh/sh.1

@@ -1274,7 +1274,7 @@ suitable for reinput to the shell.
 Continue the specified jobs
 (or the current job if no jobs are given)
 in the background.
-.It Ic command Ar cmd Op Ar arg ...
+.It Ic builtin Ar cmd Op Ar arg ...
 Execute the specified builtin command,
 .Ar cmd .
 This is useful when the user wishes to override a shell function
@@ -1333,6 +1333,26 @@ A synonym for the
 .Ic cd
 builtin command.
 .It Xo
+.Ic command
+.Op Fl p
+.Oo
+.Ar utility
+.Op Ar argument ...
+.Oc
+.Xc
+Execute the specified
+.Ar utility
+as a simple command (see the
+.Sx Simple Commands
+section).
+.Pp
+If the
+.Fl p
+option is specified, the command search is performed using a
+default value of
+.Ev PATH
+that is guaranteed to find all of the standard utilities.
+.It Xo
 .Ic echo
 .Op Fl e | Fl n
 .Op Ar string