Date: Mon, 23 Jul 2001 14:06:20 +0300 From: Peter Pentchev <roam@orbitel.bg> To: arch@FreeBSD.org Cc: audit@FreeBSD.org Subject: Re: sysctl(8) enhancement: display sysctl MIB's Message-ID: <20010723140620.A52175@ringworld.oblivion.bg> In-Reply-To: <20010723104201.855893E2F@bazooka.unixfreak.org>; from dima@unixfreak.org on Mon, Jul 23, 2001 at 03:42:01AM -0700 References: <20010723004034.I882@ringworld.oblivion.bg> <20010723104201.855893E2F@bazooka.unixfreak.org>
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On Mon, Jul 23, 2001 at 03:42:01AM -0700, Dima Dorfman wrote:
[snip]
>
> I don't think checking printf()'s return value does anything other
> than add more lines to the program. Most (none?) of the other
> programs don't do it. Besides, what can you do when it fails?
> Remember, err(3) calls it too... (well, it calls fprintf to write to
> stderr, but you get the idea)
[snip]
>
> If you're going to make show_varname() return something to indicate an
> error (your code doesn't do that right now, but the return type is
> 'int', and the comment says that it might fail in the future), you
> should check the return value when you call it. Actually, I think
> making the return type 'void' makes more sense: this is a support
> routine (as opposed to an interface to something), and if it detects
> an error, calling one of the err(3) functions would be cleaner than
> doing error checking all over the place.
>
>
> Other than that, I think it's a good idea.
OK, a revised patch follows..
G'luck,
Peter
--
If the meanings of 'true' and 'false' were switched, then this sentence wouldn't be false.
Index: src/sbin/sysctl/sysctl.8
===================================================================
RCS file: /home/ncvs/src/sbin/sysctl/sysctl.8,v
retrieving revision 1.36
diff -u -r1.36 sysctl.8
--- src/sbin/sysctl/sysctl.8 2001/07/13 09:09:48 1.36
+++ src/sbin/sysctl/sysctl.8 2001/07/23 11:05:00
@@ -40,7 +40,7 @@
.Nd get or set kernel state
.Sh SYNOPSIS
.Nm
-.Op Fl bNnox
+.Op Fl bmNnox
.Ar name Ns Op = Ns Ar value
.Ar ...
.Nm
@@ -71,6 +71,11 @@
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 m
+Specify that the MIB numerical value should be printed before the name.
+This flag only takes effect if
+.Fl n
+is not specified.
.It Fl N
Show only variable names, not their values.
This is particularly useful with shells that offer programmable
Index: src/sbin/sysctl/sysctl.c
===================================================================
RCS file: /home/ncvs/src/sbin/sysctl/sysctl.c,v
retrieving revision 1.37
diff -u -r1.37 sysctl.c
--- src/sbin/sysctl/sysctl.c 2001/06/18 21:06:24 1.37
+++ src/sbin/sysctl/sysctl.c 2001/07/23 11:05:00
@@ -58,10 +58,11 @@
#include <string.h>
#include <unistd.h>
-static int aflag, bflag, Nflag, nflag, oflag, xflag;
+static int aflag, bflag, mflag, Nflag, nflag, oflag, xflag;
static int oidfmt(int *, int, char *, u_int *);
static void parse(char *);
+static void show_varname(const char *, const int *, int);
static int show_var(int *, int);
static int sysctl_all (int *oid, int len);
static int name2oid(char *, int *);
@@ -71,8 +72,8 @@
{
(void)fprintf(stderr, "%s\n%s\n",
- "usage: sysctl [-bNnox] variable[=value] ...",
- " sysctl [-bNnox] -a");
+ "usage: sysctl [-bmNnox] variable[=value] ...",
+ " sysctl [-bmNnox] -a");
exit(1);
}
@@ -83,7 +84,7 @@
setbuf(stdout,0);
setbuf(stderr,0);
- while ((ch = getopt(argc, argv, "AabNnowxX")) != -1) {
+ while ((ch = getopt(argc, argv, "AabmNnowxX")) != -1) {
switch (ch) {
case 'A':
/* compatibility */
@@ -95,6 +96,9 @@
case 'b':
bflag = 1;
break;
+ case 'm':
+ mflag = 1;
+ break;
case 'N':
Nflag = 1;
break;
@@ -369,6 +373,30 @@
}
/*
+ * This formats and outputs the name of one variable.
+ * If the -m command-line flag was specified, the MIB value
+ * is also printed out.
+ */
+
+static void
+show_varname(const char *name, const int *oid, int len)
+{
+ int i;
+
+ if (nflag)
+ return;
+
+ if (mflag) {
+ for (i = 0; i < len-1; i++)
+ printf("%X.", oid[i]);
+ printf("%X ", oid[i]);
+ }
+
+ printf("%s: ", name);
+ return;
+}
+
+/*
* This formats and outputs the value of one variable
*
* Returns zero if anything was actually output.
@@ -397,7 +425,7 @@
err(1, "sysctl name %d %d %d", i, j, errno);
if (Nflag) {
- printf("%s", name);
+ show_varname(name, oid, nlen);
return (0);
}
@@ -430,14 +458,12 @@
p = val;
switch (*fmt) {
case 'A':
- if (!nflag)
- printf("%s: ", name);
+ show_varname(name, oid, nlen);
printf("%s", p);
return (0);
case 'I':
- if (!nflag)
- printf("%s: ", name);
+ show_varname(name, oid, nlen);
fmt++;
val = "";
while (len >= sizeof(int)) {
@@ -452,8 +478,7 @@
return (0);
case 'L':
- if (!nflag)
- printf("%s: ", name);
+ show_varname(name, oid, nlen);
fmt++;
val = "";
while (len >= sizeof(long)) {
@@ -468,8 +493,7 @@
return (0);
case 'P':
- if (!nflag)
- printf("%s: ", name);
+ show_varname(name, oid, nlen);
printf("%p", *(void **)p);
return (0);
@@ -487,16 +511,14 @@
else
func = NULL;
if (func) {
- if (!nflag)
- printf("%s: ", name);
+ show_varname(name, oid, nlen);
return ((*func)(len, p));
}
/* FALL THROUGH */
default:
if (!oflag && !xflag)
return (1);
- if (!nflag)
- printf("%s: ", name);
+ show_varname(name, oid, nlen);
printf("Format:%s Length:%d Dump:0x", fmt, len);
while (len-- && (xflag || p < val + 16))
printf("%02x", *p++);
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