From 8e39d38f76071e902cb171fe5e30e0a6cfff587a Mon Sep 17 00:00:00 2001
From: Dave <dmakray@gmail.com>
Date: Tue, 30 Oct 2018 22:32:38 -0400
Subject: [PATCH] Add grep command

---
 src/grep.hs | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 src/grep.hs

diff --git a/src/grep.hs b/src/grep.hs
new file mode 100644
index 0000000..f1e9a80
--- /dev/null
+++ b/src/grep.hs
@@ -0,0 +1,20 @@
+module Main where
+
+import Data.List          (isInfixOf)
+import System.Environment (getArgs)
+
+-- grep
+main :: IO()
+main = do
+  args <- getArgs
+  
+  --Get the search pattern from the first argument
+  let pattern = head args
+  
+  --Read all file names on command line
+  fileContents <- mapM readFile $ tail args
+
+  let lineContents = concat $ map lines fileContents
+  let selection = filter (isInfixOf pattern) lineContents
+
+  mapM_ putStrLn selection