diff --git a/tail_less_cat_head.md b/tail_less_cat_head.md
index 26b5afd..4727dcb 100644
--- a/tail_less_cat_head.md
+++ b/tail_less_cat_head.md
@@ -1,4 +1,4 @@
-# Cat, Less, Tail and Head
+# Cat, Less, Tail, Head and Tee
**Table of Contents**
@@ -27,6 +27,14 @@
* [combining head and tail](#combining-head-and-tail)
* [Further Reading for head](#further-reading-for-head)
* [Text Editors](#text-editors)
+* [Tee](#Tee)
+ * [Write output to stdout, and also to a file](#output-to-stdout)
+ * [Write the output to two commands](#output-to-two-commands)
+ * [Misc Tee Command Operations](#Misc)
+
+
+
+
@@ -680,3 +688,39 @@ Powerful text editors
* [sublime](https://www.sublimetext.com/)
Check out [this analysis](https://github.com/jhallen/joes-sandbox/tree/master/editor-perf) for some performance/feature comparisons of various text editors
+
+
+## Tee
+
+### Write output to stdout, and also to a file
+```
+ The following command displays output only on the screen (stdout).
+ $ ls
+
+ The following command writes the output only to the file and not to the screen.
+ $ ls > file
+
+ The following command (with the help of tee command) writes the output both to the screen (stdout) and to the file.
+ $ ls | tee file
+```
+
+### Write the output to two commands
+```
+ You can also use tee command to store the output of a command to a file and redirect the same output as an input to another command.
+
+ The following command will take a backup of the crontab entries, and pass the crontab entries as an input to sed command which will do the substituion. After the substitution, it will be added as a new cron job.
+
+ $ crontab -l | tee crontab-backup.txt | sed 's/old/new/' | crontab –
+```
+
+### Misc Tee Command Operations
+```
+ By default tee command overwrites the file. You can instruct tee command to append to the file using the option –a as shown below.
+
+ $ ls | tee –a file
+
+ You can also write the output to multiple files as shown below.
+
+ $ ls | tee file1 file2 file3
+
+```