This is a text-only version of the following page on https://raymii.org:
---
Title       : 	Bash Bits: Trap Control C (SIGTERM)
Author      : 	Remy van Elst
Date        : 	14-09-2013
URL         : 	https://raymii.org/s/snippets/Bash_Bits_Trap_Control_C_SIGTERM.html
Format      : 	Markdown/HTML
---



Bash Bits are small examples and tips for Bash Scripts. This bash bit shows you
how to capture a Control C signal in a bash script, for example, to clean up any
temp or pid files when your script is killed or closed.

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[All Bash Bits can be found using this link][2]

Exit signals are sent when for example you use `pkill` or `killall`. If you do
not specify a number, a `SIGTERM` is sent. If you for example do a `pkill -9
firefox`, it sents a `SIGKILL`. If you have a bash script which places a temp
file, or a pid file, you might want to clean that up before you exit.

We create a function to catch the exit signals first, then we bind this function
to the exit signals.

This is the `control_c` function:

    
    
    function control_c {
        echo -en "\n## Caught SIGINT; Clean up and Exit \n"
        rm /var/run/myscript.pid
        exit $?
    }
    

Then we use the trap command to bind the function to an exit signal. Here I bind
it to both `SIGINT` and `SIGTERM`:

    
    
    trap control_c SIGINT
    trap control_c SIGTERM
    

Now when the script gets killed or you do a control c, the script will remove
it's pid file. You can put anything in the `control_c` function, I mostly use it
for cleanup.

[Read more about Signals here on The Linux Documentation Project][3]

   [1]: https://www.digitalocean.com/?refcode=7435ae6b8212
   [2]: https://raymii.org/s/tags/bash-bits.html
   [3]: http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_12_01.html

---

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