From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Tue, 17 Jan 2012 02:41:24 +0000 (-0800)
Subject: varsym - Add -x option
X-Git-Tag: v3.0.0~46
X-Git-Url: https://gitweb.dragonflybsd.org/~tuxillo/dragonfly.git/commitdiff_plain/2f5c5b87d512dff27a8ab2b5bddb25a6a1c488a1

varsym - Add -x option

* Add the -x option which causes varsym to set per-process variables and
  then exec the command line from the first non-varsym-assign.  For example:

  varsym -x UNAME_n=fubar uname
  varsym -x UNAME_n=fubar /bin/csh
  etc
---

diff --git a/bin/varsym/varsym.1 b/bin/varsym/varsym.1
index ed5fbb3b31..ee61ca6dd7 100644
--- a/bin/varsym/varsym.1
+++ b/bin/varsym/varsym.1
@@ -32,11 +32,19 @@
 .Nd get and set user and system-wide variables for variant symlinks
 .Sh SYNOPSIS
 .Nm
-.Op Fl adpqsu
+.Op Fl adpqsux
 .Oo
 .Ar var Ns Op Ns Cm = Ns Ar data
 .Ar ...
 .Oc
+.Nm
+.Fl x
+.Oo
+.Ar var Ns Op Ns Cm = Ns Ar data
+.Ar ...
+.Oc
+.Ar command
+.Ar args
 .Sh DESCRIPTION
 The
 .Nm
@@ -66,6 +74,9 @@ Note that since
 .Nm
 is run as its own process, using this option to set a variable will not
 affect your shell's namespace.
+Instead you might want to use the
+.Fl x
+option to set local varsyms and exec a command.
 .It Fl q
 Quiet mode.
 When retrieving a variable only its data is printed.
@@ -75,7 +86,14 @@ to system-specific variables.
 .It Fl u
 This option causes variables to be set on a per-user-id basis and restricts
 retrievals to user-specific variables.
-This is the default.
+This is the default unless
+.Fl x
+is used.
+.It Fl x
+This option causes variables to be set only within the
+.Nm
+process and its children, and also allows you to specify a command and
+arguments to exec after the var=data specifications.
 .El
 .Sh DIAGNOSTICS
 The
diff --git a/bin/varsym/varsym.c b/bin/varsym/varsym.c
index 5ae3a0cdef..802e67cf38 100644
--- a/bin/varsym/varsym.c
+++ b/bin/varsym/varsym.c
@@ -33,8 +33,9 @@
 #include <unistd.h>
 #include <sys/varsym.h>
 
-static void usage(void);
 static void dumpvars(char *buf, int bytes);
+static int doexec(char **av);
+static void usage(void);
 
 int
 main(int ac, char **av)
@@ -45,8 +46,9 @@ main(int ac, char **av)
 	int deleteOpt = 0;
 	int verboseOpt = 1;
 	int allOpt = 0;
+	int execok = 0;
 
-	while ((i = getopt(ac, av, "adhpqsu")) != -1) {
+	while ((i = getopt(ac, av, "adhpqsux")) != -1) {
 		switch (i) {
 		case 'a':
 			allOpt = 1;
@@ -69,6 +71,11 @@ main(int ac, char **av)
 			mask = VARSYM_USER_MASK;
 			level = VARSYM_USER;
 			break;
+		case 'x':
+			mask = VARSYM_PROC_MASK;
+			level = VARSYM_PROC;
+			execok = 1;
+			break;
 		case 'h':
 		default:
 			usage();
@@ -102,13 +109,21 @@ main(int ac, char **av)
 		if (data)
 			*data++ = 0;
 
-		if (deleteOpt) {
+		if (execok) {
+			if (deleteOpt) {
+				usage();
+				exit(1);
+			}
+			if (data) {
+				error = varsym_set(level, name, data);
+			} else {
+				error = doexec(av + optind);
+			}
+		} else if (deleteOpt) {
 			error = varsym_set(level, name, NULL);
-		}
-		else if (data) {
+		} else if (data) {
 			error = varsym_set(level, name, data);
-		}
-		else {
+		} else {
 			error = varsym_get(mask, name, buf, sizeof(buf));
 			if (error >= 0 && error <= (int)sizeof(buf)) {
 				if (verboseOpt)
@@ -126,23 +141,32 @@ main(int ac, char **av)
 static void
 dumpvars(char *buf, int bytes)
 {
-    int b;
-    int i;
-    char *vname = NULL;
-    char *vdata = NULL;
-
-    for (b = i = 0; i < bytes; ++i) {
-	if (buf[i] == 0) {
-	    if (vname == NULL) {
-		vname = buf + b;
-	    } else {
-		vdata = buf + b;
-		printf("%s=%s\n", vname, vdata);
-		vname = vdata = NULL;
-	    }
-	    b = i + 1;
+	int b;
+	int i;
+	char *vname = NULL;
+	char *vdata = NULL;
+
+	for (b = i = 0; i < bytes; ++i) {
+		if (buf[i] == 0) {
+			if (vname == NULL) {
+				vname = buf + b;
+			} else {
+				vdata = buf + b;
+				printf("%s=%s\n", vname, vdata);
+				vname = vdata = NULL;
+			}
+			b = i + 1;
+		}
 	}
-    }
+}
+
+static int
+doexec(char **av)
+{
+	int error;
+
+	error = execvp(av[0], av);
+	return (error);
 }
 
 static void