Implement -e option. It modifies the output produced by sysctl(8) in

such a way that the name and the value of the variable(s) are separated
with `=' instead of the usual `: '.  This is useful for producing output
that can be fed back to the sysctl utility (pasted to sysctl.conf, for
example).

Reviewed by:	rwatson
Approved by:	markm
MFC after:	2 weeks

2 files changed, 31 insertions, 13 deletions

diff --git a/sbin/sysctl/sysctl.8 b/sbin/sysctl/sysctl.8
index bd5f1f2..a58cfd0 100644
--- a/sbin/sysctl/sysctl.8
+++ b/sbin/sysctl/sysctl.8
@@ -40,11 +40,11 @@
 .Nd get or set kernel state
 .Sh SYNOPSIS
 .Nm
-.Op Fl bNnox
+.Op Fl beNnox
 .Ar name Ns Op = Ns Ar value
 .Ar ...
 .Nm
-.Op Fl bNnox
+.Op Fl beNnox
 .Fl a
 .Sh DESCRIPTION
 The
@@ -71,6 +71,16 @@ the command line.
 Force the value of the variable(s) to be output in raw, binary format.
 No names are printed and no terminating newlines are output.
 This is mostly useful with a single variable.
+.It Fl e
+Separate the name and the value of the variable(s) with `='.
+This is useful for producing output which can be fed back to the
+.Nm
+utility.
+This option is ignored if either
+.Fl N
+or
+.Fl n
+is specified, or a variable is being set.
 .It Fl N
 Show only variable names, not their values.
 This is particularly useful with shells that offer programmable
diff --git a/sbin/sysctl/sysctl.c b/sbin/sysctl/sysctl.c
index 1d22550..5ffb810 100644
--- a/sbin/sysctl/sysctl.c
+++ b/sbin/sysctl/sysctl.c
@@ -58,7 +58,7 @@ static const char rcsid[] =
 #include <string.h>
 #include <unistd.h>
 
-static int	aflag, bflag, Nflag, nflag, oflag, xflag;
+static int	aflag, bflag, eflag, Nflag, nflag, oflag, xflag;
 
 static int	oidfmt(int *, int, char *, u_int *);
 static void	parse(char *);
@@ -71,8 +71,8 @@ usage(void)
 {
 
 	(void)fprintf(stderr, "%s\n%s\n",
-	    "usage: sysctl [-bNnox] variable[=value] ...",
-	    "       sysctl [-bNnox] -a");
+	    "usage: sysctl [-beNnox] variable[=value] ...",
+	    "       sysctl [-beNnox] -a");
 	exit(1);
 }
 
@@ -83,7 +83,7 @@ main(int argc, char **argv)
 	setbuf(stdout,0);
 	setbuf(stderr,0);
 
-	while ((ch = getopt(argc, argv, "AabNnowxX")) != -1) {
+	while ((ch = getopt(argc, argv, "AabeNnowxX")) != -1) {
 		switch (ch) {
 		case 'A':
 			/* compatibility */
@@ -95,6 +95,9 @@ main(int argc, char **argv)
 		case 'b':
 			bflag = 1;
 			break;
+		case 'e':
+			eflag = 1;
+			break;
 		case 'N':
 			Nflag = 1;
 			break;
@@ -380,7 +383,7 @@ static int
 show_var(int *oid, int nlen)
 {
 	u_char buf[BUFSIZ], *val, *p;
-	char name[BUFSIZ], *fmt;
+	char name[BUFSIZ], *fmt, *sep;
 	int qoid[CTL_MAXNAME+2];
 	int i;
 	size_t j, len;
@@ -401,6 +404,11 @@ show_var(int *oid, int nlen)
 		return (0);
 	}
 
+	if (eflag)
+		sep = "=";
+	else
+		sep = ": ";
+
 	/* find an estimate of how much we need for this var */
 	j = 0;
 	i = sysctl(oid, nlen, 0, &j, 0, 0);
@@ -431,13 +439,13 @@ show_var(int *oid, int nlen)
 	switch (*fmt) {
 	case 'A':
 		if (!nflag)
-			printf("%s: ", name);
+			printf("%s%s", name, sep);
 		printf("%s", p);
 		return (0);
 		
 	case 'I':
 		if (!nflag)
-			printf("%s: ", name);
+			printf("%s%s", name, sep);
 		fmt++;
 		val = "";
 		while (len >= sizeof(int)) {
@@ -453,7 +461,7 @@ show_var(int *oid, int nlen)
 
 	case 'L':
 		if (!nflag)
-			printf("%s: ", name);
+			printf("%s%s", name, sep);
 		fmt++;
 		val = "";
 		while (len >= sizeof(long)) {
@@ -469,7 +477,7 @@ show_var(int *oid, int nlen)
 
 	case 'P':
 		if (!nflag)
-			printf("%s: ", name);
+			printf("%s%s", name, sep);
 		printf("%p", *(void **)p);
 		return (0);
 
@@ -488,7 +496,7 @@ show_var(int *oid, int nlen)
 			func = NULL;
 		if (func) {
 			if (!nflag)
-				printf("%s: ", name);
+				printf("%s%s", name, sep);
 			return ((*func)(len, p));
 		}
 		/* FALL THROUGH */
@@ -496,7 +504,7 @@ show_var(int *oid, int nlen)
 		if (!oflag && !xflag)
 			return (1);
 		if (!nflag)
-			printf("%s: ", name);
+			printf("%s%s", name, sep);
 		printf("Format:%s Length:%d Dump:0x", fmt, len);
 		while (len-- && (xflag || p < val + 16))
 			printf("%02x", *p++);