Shell – Ctrl-C kills whole line while Ctrl-Z doesn’t

job-controljobsshell

I am running multiple commands on the command line separated using semi-colons:

cmd1; cmd2; cmd3

If I press Ctrl+C on the above, it would kill all commands instead of just the one which is executing currently.

kartik@kartikpc:~/junk/exp$ ls
test1  test2
kartik@kartikpc:~/junk/exp$ cat; ls
cat is running
cat is running
^C
kartik@kartikpc:~/junk/exp

But Ctrl+Z would only suspend the current process and continue with the next one.

kartik@kartikpc:~/junk/exp$ ls
test1  test2
kartik@kartikpc:~/junk/exp$ cat; ls
cat is running 
cat is running
^Z
[1]+  Stopped                 cat
test1  test2
kartik@kartikpc:~/junk/exp$

Why is there a disperancy in behaviour, and is there any way to make Ctrl+C behave like Ctrl+Z?

I'm actually running a server through tmux session as follows node app.js; $bash, and when I do a Ctrl+C to kill the server, it kills bash as well. I want to return to shell. Is there any alternative to achieve the behavior I want?

[UPDATE]

tcsh behaves the same with Ctrl+C and Ctrl+Z. It would always act on all commands just as bash is doing with onlt Ctrl+C. But bringing back the job with fg would only bring back cat and not ls.

[kartika@vm-kartika-vnc ~/junk]$ ls
file1  file2
[kartika@vm-kartika-vnc ~/junk]$ echo $SHELL
/bin/tcsh
[kartika@vm-kartika-vnc ~/junk]$ cat; ls
cat is running 
cat is running
^C
[kartika@vm-kartika-vnc ~/junk]$ cat ; ls
cat is running
cat is running
^Z
Suspended
[kartika@vm-kartika-vnc ~/junk]$ jobs
[1]  + Suspended                     cat
[kartika@vm-kartika-vnc ~/junk]$ fg
cat                                     // Pressing ctrl-d here to exit cat
[kartika@vm-kartika-vnc ~/junk]$

System Information:

kartik@kartikpc:~/junk/exp$ uname -a
Linux kartikpc 3.13.0-70-generic #113-Ubuntu SMP Mon Nov 16 18:34:13 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
kartik@kartikpc:~/junk/exp$ echo $SHELL
/bin/bash

Best Answer

You need to look up bash job controls. There is a decent explanation here: http://web.mit.edu/gnu/doc/html/features_5.html

But in a nutshell Ctrl+C will kill the commands (all of the line) and Ctrl+Z will background the running command. In your case it is backgrounding cat (supresses output and halts processing) and then continuing on to run the ls command.

You can confirm this by checking the process list and you will find your cat is still in the list.

To bring that job to the foreground look into the fg command.

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