1 files changed, 31 insertions, 0 deletions
diff --git a/grep-group b/grep-group
new file mode 100755
index 0000000..06bc923
--- /dev/null
+++ b/grep-group
@@ -0,0 +1,31 @@
+#!/usr/bin/perl
+use warnings;
+use strict;
+use File::Basename;
+
+if (@ARGV < 1) {
+  print "usage: cat | ", basename($0), " <regexp>\n";
+  exit 2;
+}
+
+my $pattern = shift;
+
+while (<>) {
+	my $line = $_;
+	chomp($line);
+
+	if (my @matches = $line =~ /$pattern/) {
+		if ($#- != 0) {
+			if (scalar(@matches) == 1) {
+				printf "%s\n", $matches[0];
+			} else {
+				for my $match (@matches) {
+					print $match;
+				}
+				printf "\n";
+			}
+		} else {
+			printf "%s\n", $&;
+		}
+	}
+}