grep script use sed

bashrc/grep3c.sh

@@ -0,0 +1,35 @@
+#!/bin/env bash
+
+# if there is only one argument, exit
+
+case $# in 
+        1);;
+        *) echo "Usage: $0 pattern";exit;;
+esac;
+
+# again - I hope the argument doesn't contain a /
+
+sed -n '
+'/$1/' !{
+        # put the non-matching line in the hold buffer
+        h
+}
+'/$1/' {
+        # found a line that matches
+        # add the next line to the pattern space
+        N
+        # exchange the previous line with the 
+        # 2 in pattern space
+        x
+        # now add the two lines back
+        G
+        # and print it.
+        p
+        # add the three hyphens as a marker
+        a\
+---
+        # remove first 2 lines
+        s/.*\n.*\n\(.*\)$/\1/
+        # and place in the hold buffer for next time
+        h
+}'