Added documentation to the file command

_commands/tools/file.md

@@ -2,23 +2,59 @@
 ---
 
 file
----
-TODO: Add documentation for this command by submitting a pull request.
+-------
+<!--TODO: Add documentation for this command by submitting a pull request.-->
 <!-- one line explanation would go here -->
+`file` prints the file type of a file in a human-readable format
 
 <!-- minimal example -->
 ~~~ bash
-*short* example of command usage and output
+$ file test.cpp
+test.cpp: c program text, UTF-8 Unicode text
+
 ~~~
 
+
 <!--more-->
 
 ### Useful Options / Examples
 
-#### Example command
+Useful on Unix since file extensions sometimes are completely unrelated to their actual type.
 
-##### Break it down
+~~~bash
+file starter-files.csvs
+starter-files.csv: Zip archive data, at least v2.0 to extract
+~~~
+
+#### `file`
+
+~~~bash
+$ file [options] filename ...
+~~~
+
+Options include:
 
-#### Example command
+1. `b` to only show the file type (rather than the file name followed by the file type)
+2. `i` to show the file's mime type
+3. `z` to view compressed files without decompressing
+
+
+----
+
+#### `file -bi filename`
+
+~~~bash
+$ file -z bar.txt.gz
+$ bar.txt.gz: ASCII text (gzip compressed data, was "bar.txt", last modified: Wed Sep  7 19:31:23 2016, from Unix)
+
+file -bi file.txt
+file.txt: text/plain; charset=us-ascii
+~~~
 
 ##### Break it down
+
+* The -b option will print only the file type
+* The -i option will print the file's mime type rather than a human-readable description of the file type
+----
+
+