X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=db-hash;h=9b159ff85d716e5d3ee484a37afc1f8e2bf34679;hb=1886c7247cb16ed68a78cd5550b152689a465999;hp=d9ad8af30d0746c9b89e9e35da16ef65ac5efcfb;hpb=3300ac8c577fe9138b330f7b8f596963085852ac;p=bin.git

diff --git a/db-hash b/db-hash
index d9ad8af..9b159ff 100755
--- a/db-hash
+++ b/db-hash
@@ -1,9 +1,8 @@
 #! /usr/bin/perl
-# , and is released
+# db-hash creates databases and queries it, and is released
 # under the terms of the GPL version 2, or any later version, at your
 # option. See the file README and COPYING for more information.
-# Copyright 2009 by Don Armstrong <don@donarmstrong.com>.
-# $Id: perl_script 1432 2009-04-21 02:42:41Z don $
+# Copyright 2009-11 by Don Armstrong <don@donarmstrong.com>.
 
 
 use warnings;
@@ -27,6 +26,8 @@ db-hash - create a database and query using it
   --dump, -D dump dbname
   --missing-newline, -n output a newline for unhashed keys
   --include-key, -k output the key as well as the value
+  --reverse, -r reverse (values to key)
+  --key-to-itself map key to itself
   --debug, -d debugging level (Default 0)
   --help, -h display this help
   --man, -m display manual
@@ -52,6 +53,14 @@ Dump database to stdout
 
 Output the key as well as the value. (Off by default)
 
+=item B<--reverse>
+
+Map values to a key
+
+=item B<--key-to-itself>
+
+Map the key to itself (On by default in reverse hashes)
+
 =item B<--missing-newline,-n>
 
 If a key doesn't exist in the database, output a newline. (Forced on
@@ -102,6 +111,7 @@ GetOptions(\%options,
 	   'dump|D',
 	   'include_key|include-key|k!',
 	   'reverse|r!',
+	   'key_to_itself|key-to-itself|K',
 	   'missing_newline|missing-newline|n!',
 	   'debug|d+','help|h|?','man|m');
 
@@ -132,6 +142,12 @@ else {
 	die "Unable to open $db for writing: $!";
 }
 
+if ($options{reverse}) {
+    if (not exists $options{key_to_itself}) {
+	$options{key_to_itself} = 1;
+    }
+}
+
 if (not defined $options{include_key}) {
     $options{include_key} = $options{dump} ? 0 : 1;
 }
@@ -143,8 +159,8 @@ if ($options{update} or $options{create}) {
 	chomp;
 	my ($key,@val) = split /\t/;
 	if ($options{reverse}) {
-	    for my $val_key (@val) {
-		$fast_db{$val_key} = [make_list($fast_db{$val_key})//[],$key];
+	    for my $val_key (@val,$options{key_to_itself}?$key:()) {
+		$fast_db{$val_key} = [make_list($fast_db{$val_key} // []),$key];
 	    }
 	}
 	else {