In new BSDs changes to argv[] do not show up in ps(1) output,

instead one must use setproctitle().  This was already addressed
by change #6457, but the below has a new variant for FreeBSD 4.0
or later, and the matter is also documented more.
Subject: [ID 20000801.007] setting $0 on FreeBSD 4.x does not get reflected in /bin/ps
Message-Id: <20000801154139.A53740@yahoo-inc.com>

p4raw-link: @6457 on //depot/perl: 0c9177abdae6e91f4dfdab2ef3cc817ec901e51eon //depot/metaconfig: efc5abcdbec468dfb20e18acbe3ab6c1cd9e92c3

p4raw-id: //depot/perl@6483

5 files changed, 46 insertions, 4 deletions

diff --git a/Configure b/Configure
index 5a541b84e0..54c85e2338 100755
--- a/Configure
+++ b/Configure
@@ -20,7 +20,7 @@
 
 # $Id: Head.U,v 3.0.1.9 1997/02/28 15:02:09 ram Exp $
 #
-# Generated on Tue Aug  1 20:27:06 EET DST 2000 [metaconfig 3.0 PL70]
+# Generated on Wed Aug  2 03:07:08 EET DST 2000 [metaconfig 3.0 PL70]
 # (with additional metaconfig patches by perlbug@perl.com)
 
 cat >/tmp/c1$$ <<EOF
@@ -625,6 +625,7 @@ i_grp=''
 i_iconv=''
 i_ieeefp=''
 i_inttypes=''
+i_libutil=''
 i_limits=''
 i_locale=''
 i_machcthr=''
@@ -14372,6 +14373,10 @@ eval $inhdr
 set ieeefp.h i_ieeefp
 eval $inhdr
 
+: see if this is a libutil.h system
+set libutil.h i_libutil
+eval $inhdr
+
 : see if locale.h is available
 set locale.h i_locale
 eval $inhdr
@@ -15681,6 +15686,7 @@ i_grp='$i_grp'
 i_iconv='$i_iconv'
 i_ieeefp='$i_ieeefp'
 i_inttypes='$i_inttypes'
+i_libutil='$i_libutil'
 i_limits='$i_limits'
 i_locale='$i_locale'
 i_machcthr='$i_machcthr'
diff --git a/config_h.SH b/config_h.SH
index 70aaefe2f2..e66e0c5ed0 100644
--- a/config_h.SH
+++ b/config_h.SH
@@ -3156,5 +3156,11 @@ sed <<!GROK!THIS! >$CONFIG_H -e 's!^#undef\(.*/\)\*!/\*#define\1 \*!' -e 's!^#un
 #define PERL_XS_APIVERSION "$xs_apiversion"
 #define PERL_PM_APIVERSION "$pm_apiversion"
 
+/* I_LIBUTIL:
+ *	This symbol, if defined, indicates that <libutil.h> exists and
+ *	should be included.
+ */
+#$i_libutil	I_LIBUTIL		/**/
+
 #endif
 !GROK!THIS!
diff --git a/mg.c b/mg.c
index 84fff24278..3cf8f59a6a 100644
--- a/mg.c
+++ b/mg.c
@@ -1999,6 +1999,30 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	break;
 #ifndef MACOS_TRADITIONAL
     case '0':
+#ifdef HAS_SETPROCTITLE
+	/* The BSDs don't show the argv[] in ps(1) output, they
+	 * show a string from the process struct and provide
+	 * the setproctitle() routine to manipulate that. */
+	{
+	    s = SvPV(sv, len);
+#   if __FreeBSD_version >= 400000
+	    /* The - removes the "perl: " prefix,
+	     * but not the "(perl) suffix from the ps(1)
+	     * output, because that's what ps(1) shows if the
+	     * argv[] is modified. */
+	    setproctitle("-%s", s, len + 1);
+#   else	/* old FreeBSDs, NetBSD, OpenBSD */
+	    /* This doesn't really work if you assume that
+	     * $0 = 'foobar'; will wipe out 'perl' from the $0
+	     * because in ps(1) output the result will be like
+	     * sprintf("perl: %s (perl)", s)
+	     * I guess this is a security feature:
+	     * one (a user process) cannot get rid of the original name.
+	     * --jhi */
+	    setproctitle("%s", s);
+#   endif
+	}
+#endif
 	if (!PL_origalen) {
 	    s = PL_origargv[0];
 	    s += strlen(s);
@@ -2054,9 +2078,6 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	    for (i = 1; i < PL_origargc; i++)
 		PL_origargv[i] = Nullch;
 	}
-#ifdef HAS_SETPROCTITLE
-	setproctitle("%s", SvPV_nolen(sv));
-#endif
 	break;
 #endif
 #ifdef USE_THREADS
diff --git a/perl.h b/perl.h
index f01be71d08..48e8801c6f 100644
--- a/perl.h
+++ b/perl.h
@@ -3324,6 +3324,10 @@ typedef struct am_table_short AMTS;
 
 #endif /* IAMSUID */
 
+#ifdef I_LIBUTIL
+#   include <libutil.h>		/* setproctitle() in some FreeBSDs */
+#endif
+
 /* and finally... */
 #define PERL_PATCHLEVEL_H_IMPLICIT
 #include "patchlevel.h"
diff --git a/pod/perlvar.pod b/pod/perlvar.pod
index 15308e45aa..e75cf35f73 100644
--- a/pod/perlvar.pod
+++ b/pod/perlvar.pod
@@ -691,6 +691,11 @@ program sees.  This is more useful as a way of indicating the current
 program state than it is for hiding the program you're running.
 (Mnemonic: same as B<sh> and B<ksh>.)
 
+Note for BSD users: setting C<$0> does not completely remove "perl"
+from the ps(1) output.  For example, setting C<$0> to C<"foobar"> will
+result in C<"perl: foobar (perl)">.  This is an operating system
+feature.
+
 =item $[
 
 The index of the first element in an array, and of the first character