Added -n option to kill_known_host to print key only.

Added -p option to kill_known_host to allow partial matches.

git-svn-id: https://svn.cambridge.iain.cx/profile/trunk@43 6be0d1a5-5cfe-0310-89b6-964be062b18b

diff --git a/kill_known_host b/kill_known_host
index acc6385..46dbb83 100755 (executable)
--- a/kill_known_host
+++ b/kill_known_host
@@ -3,21 +3,32 @@
 # $Id$
 #
 # kill_known_host: Remove an entry from the ssh hosts file.
-# Usage: kill_known_host <IP>
-#        kill_known_host <hostname>
+# Usage: kill_known_host [options] <IP>|<hostname>
+# Options: -n   Only report key; don't delete it.
+#          -p   Allow partial match.
+# Example: kill_known_host -p www
+#          Remove all keys with hostname beginning www.
 # Exits:   0 on success.
 #          1 on error.
 #        111 if the entry didn't exist.
 # Notes: Based on Jim's kill-known-host.
 #
 
+use Getopt::Std;
+
 my $KNOWN_HOSTS = "$ENV{HOME}/.ssh/known_hosts";
 my $SCRATCH = "$KNOWN_HOSTS.$$";
 
+our $opt_n, $opt_p;
+getopts("np");
+
 # Check args.
 unless (@ARGV) {
-  print STDERR "Usage: kill_known_host <IP>\n";
-  print STDERR "Usage: kill_known_host <hostname>\n";
+  print STDERR "Usage: kill_known_host [options] <IP>|<hostname>\n";
+  print STDERR "Options: -n   Only report key; don't delete it.\n";
+  print STDERR "         -p   Allow partial match.\n";
+  print STDERR "Example: kill_known_host -p www\n";
+  print STDERR "         Remove all keys with hostname beginning www.\n";
   print STDERR "Exits:   0 on success.\n";
   print STDERR "         1 on error.\n";
   print STDERR "       111 if the entry didn't exist.\n";
@@ -25,33 +36,46 @@ unless (@ARGV) {
 }
 
 my $host = shift;
+my $dotstar = $opt_p ? '[^\s,]*' : '';
 my $re;
 
 # Check if it's an IP or a hostname.
 if ($host =~ /^[1-9]\d{0,2}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/) {
-  $re = "^([^\\s]+,)?$host\\s";
+  $re = "^([^\\s]+,)?$host$dotstar\\s";
 }
 else {
-  $re = "^$host\\s";
+  $re = "^$host$dotstar\[\\s,]";
 }
 
 # Read known hosts.
 open IN, "< $KNOWN_HOSTS" or die "Can't read known_hosts: $!\n";
 
 # Open scratch file.
-open OUT, "> $SCRATCH" or die "Can't open scratch file: $!\n";
+open OUT, "> $SCRATCH" or die "Can't open scratch file: $!\n" unless $opt_n;
 
 my ($in, $out) = (0, 0);
 while (<IN>) {
   $in++;
-  next if /$re/;
-  print OUT;
-  $out++;
+  if (/$re/) {
+    if ($opt_n) {
+      $out++;
+      print;
+    }
+    else { next }
+  }
+  unless ($opt_n) {
+    print OUT;
+    $out++;
+  }
 }
 
 # Cleanup.
-close OUT;
 close IN;
+if ($opt_n) {
+  exit 111 unless $out;
+  exit 0;
+}
+close OUT;
 
 # Move hosts.
 rename $SCRATCH, $KNOWN_HOSTS or die "Can't rename $KNOWN_HOSTS: $!\n";