Add the SUSv3 -p ("portable") option to both the export and readonly

builtins. This makes export/readonly print lines in the form
"export name=value".

2 files changed, 47 insertions, 3 deletions

diff --git a/bin/sh/sh.1 b/bin/sh/sh.1
index 57a21ee..34e4abe 100644
--- a/bin/sh/sh.1
+++ b/bin/sh/sh.1
@@ -1406,7 +1406,11 @@ If
 is given
 it is used as the exit status of the shell;
 otherwise the exit status of the preceding command is used.
-.It Ic export Ar name ...
+.It Xo
+.Ic export
+.Op Fl p
+.Op Ar name ...
+.Xc
 The specified names are exported so that they will
 appear in the environment of subsequent commands.
 The only way to un-export a variable is to
@@ -1420,6 +1424,11 @@ export name=value
 .Pp
 With no arguments the export command lists the names
 of all exported variables.
+If the
+.Fl p
+option is specified, the exported variables are printed as
+.Dq Ic export Ar name Ns = Ns Ar value
+lines, suitable for re-input to the shell.
 .It Ic fc Oo Fl e Ar editor Oc Op Ar first Op Ar last
 .It Ic fc Fl l Oo Fl nr Oc Op Ar first Op Ar last
 .It Ic fc Fl s Oo Ar old Ns = Ns Ar new Oc Op Ar first
@@ -1662,7 +1671,11 @@ is assumed.
 The
 .Fl e
 option exists only for backward compatibility with older scripts.
-.It Ic readonly Ar name ...
+.It Xo
+.Ic readonly
+.Op Fl p
+.Op Ar name ...
+.Xc
 Each specified
 .Ar name
 is marked as read only,
@@ -1677,6 +1690,11 @@ readonly name=value
 With no arguments the
 .Ic readonly
 command lists the names of all read only variables.
+If the
+.Fl p
+option is specified, the read-only variables are printed as
+.Dq Ic readonly Ar name Ns = Ns Ar value
+lines, suitable for re-input to the shell.
 .It Ic set Oo Fl /+abCEefIimnpTuVvx Oc Oo Fl /+o Ar longname Oc Oo
 .Fl c Ar string Oc Op Fl - Ar arg ...
 The
diff --git a/bin/sh/var.c b/bin/sh/var.c
index 42c240c..0af1eeb 100644
--- a/bin/sh/var.c
+++ b/bin/sh/var.c
@@ -531,10 +531,28 @@ exportcmd(int argc, char **argv)
 	struct var *vp;
 	char *name;
 	char *p;
+	char *cmdname;
+	int ch, values;
 	int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
 
+	cmdname = argv[0];
+	optreset = optind = 1;
+	values = 0;
+	while ((ch = getopt(argc, argv, "p")) != -1) {
+		switch (ch) {
+		case 'p':
+			values = 1;
+			break;
+		case '?':
+		default:
+			error("unknown option: -%c", optopt);
+		}
+	}
+	argc -= optind;
+	argv += optind;
+
 	listsetvar(cmdenviron);
-	if (argc > 1) {
+	if (argc != 0) {
 		while ((name = *argptr++) != NULL) {
 			if ((p = strchr(name, '=')) != NULL) {
 				p++;
@@ -559,8 +577,16 @@ found:;
 		for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
 			for (vp = *vpp ; vp ; vp = vp->next) {
 				if (vp->flags & flag) {
+					if (values) {
+						out1str(cmdname);
+						out1c(' ');
+					}
 					for (p = vp->text ; *p != '=' ; p++)
 						out1c(*p);
+					if (values && !(vp->flags & VUNSET)) {
+						out1c('=');
+						out1qstr(p + 1);
+					}
 					out1c('\n');
 				}
 			}