====== BASH - Commands - cat ======

**cat** is used to concatenate or write files, text or binary.

----

===== Write a file =====

<code bash>
cat > list.txt
</code>

type into the terminal:

<code bash>
aaa
bbb
ccc
</code>

<WRAP info>
Press **CTRL+D** to stop inputting and save file.

  * This can only be done at the start of a new line; so **<ENTER>** needs to be done against the last line before being able to do a **CTRL-D**.

This would have created the file **list.txt**.
</WRAP>


----

===== Display a file =====

<code bash>
cat list.txt
</code>

returns:

<code bash>
aaa
bbb
ccc
</code>

----

===== Concatenate multiple files =====

Create another file, named list2.txt, containing:

<code bash>
ddd
eee
</code>

----

==== Do the concatenation ====

<code bash>
cat list.txt list2.txt
</code>

returns:

<code bash>
aaa
bbb
ccc
ddd
eee
</code>

----

=== Concatenate to a new file ===

<code bash>
cat list.txt list2.txt > list3.txt
</code>

----

=== Display this new file ===

<code bash>
cat list3.txt
</code>

returns:

<code bash>
aaa
bbb
ccc
ddd
eee
</code>

----

===== Append to a file =====

<code bash>
cat >> list3.txt
</code>

enter:

<code>
fff
ggg
</code>

<WRAP info>
Press **CTRL+D** to stop inputting and save file.
</WRAP>

----

=== Display the appended file ===

<code bash>
cat list3.txt
</code>

returns:

<code bash>
aaa
bbb
ccc
ddd
eee
fff
ggg
</code>

----

===== Place data between 2 files =====

<code bash>
cat list.txt - list2.txt > list4.txt
</code>

enter:

<code bash>
hhh
</code>

<WRAP info>
Press **CTRL+D** to stop inputting and save file.
</WRAP>

----

=== Display the file ===

<code bash>
cat list4.txt
</code>

returns:

<code bash>
aaa
bbb
ccc
hhh
ddd
eee
</code>

<WRAP info>
**NOTE:**  The **hhh** data is showing in the middle of the data from the 2 input files.
</WRAP>

----

===== Join split binary files =====

<code bash>
cat video.001 video.002 video.003 > vid.avi
</code>