2
votes
1answer
20 views

calling sigprocmask from bash

I have a process that spawn a bash command with system() while the signal mask has all the signals blocked. This cannot be fixed easily. The bash command eventually execs into a process. The all ...
2
votes
2answers
49 views

Bash script to signal a concurrently running instance (same script) about a condition and increment counter

Background Here's what I want to achieve. I have a (potentially) long-running process. Now I have locking in place just fine and all is generally in order. However, since this is a scheduled job, ...
1
vote
1answer
59 views

service killed at ssh hangup [duplicate]

If I use ssh to run some command in background, that command gets killed as soon an ssh hangs up: ssh localhost -t "bash -c '(for i in 1 2 3 4 5; do sleep \$i;done)&'"; ps x|grep sleep This ...
1
vote
4answers
306 views

Ctrl-C with two simultaneous commands in bash

I want to run two commands simultaneously in bash on a Linux machine. Therefore in my ./execute.sh bash script I put: command 1 & command 2 echo "done" However when I want to stop the bash ...
2
votes
1answer
174 views

Suppress “Alarm clock: 14” from ping

I've made a simple script for rebooting my router and afterwards showing a progress bar until my computer has an internet connection again. When running the script I get the following output: The ...
4
votes
3answers
197 views

What process is running before I even get a prompt?

When I log in to a specific server I see the following: Note that I get get Last login: ... information but no prompt. I hit Ctrl+C and only then do I get my prompt, thus proving that my username ...
4
votes
1answer
339 views

A script's background process is still alive after closing the terminal

This is more of a process management/signal handling question than a Bash question. It just uses Bash to explain the issue. I'm running a Bash script in which I run a background process. This is the ...
6
votes
3answers
1k views

What's the difference between Ctrl-Z and kill -STOP?

When I run a command (make on a large project) from the shell, I can type Ctrl-Z to stop the process and return to the shell. Subsequently, I can run fg to continue the process. I'm trying to write a ...
2
votes
1answer
91 views

Chain commands with Control + C interrupt

I am trying to execute a program which loops indefinitely, and so must be forcibly interrupted. After executing the program, I want to delete it. I can do it in several steps: ./MyProg Control + C ...
6
votes
1answer
1k views

“trap … INT TERM EXIT” really necessary?

Many examples for trap use trap ... INT TERM EXIT for cleanup tasks. But is it really necessary to list all the three sigspecs? The manual says: If a SIGNAL_SPEC is EXIT (0) ARG is executed on ...
2
votes
2answers
492 views

Why can't I kill a timeout called from a Bash script with a keystroke?

[Edit: This looks similar to some other questions asking how to kill all spawned processes – the answers all seem to be to use pkill. So the core of my question may be: Is there a way to propagate ...
1
vote
0answers
225 views

Why does this pipeline get SIGTTIN?

When I run the command for i in *.log; do cat "$i" | sort; done | more, the pipeline gets a SIGTTIN signal and is stopped. bash$ for i in *.log; do cat "$i" | sort; done | more ### (one screenful of ...
8
votes
4answers
3k views

How can I kill and wait for background processes to finish in a shell script when I Ctrl+C it?

I'm trying to set up a shell script so that it runs background processes, and when I Ctrlc the shell script, it kills the children, then exits. The best that I've managed to come up with is this. It ...
6
votes
4answers
9k views

How to stop the loop bash script in terminal?

For example, #!/bin/bash while : do sl done How to terminate this bash script?
7
votes
6answers
4k views

Terminating an infinite loop

I have a command that I want to have run again automatically each time it terminates, so I ran something like this: while [ 1 ]; do COMMAND; done; but if I can't stop the loop with Ctrl-c as that ...
3
votes
1answer
774 views

Issue with WINCH signal - what am I overlooking?

I am having an issue with the WINCH signal in the following code which is from a tutorial located at developerWorks®: #!/bin/bash trap 'get_window_size' WINCH # trap when a user ...
3
votes
2answers
3k views

How can I trap a program that returns 139 (segmentation fault) in bash?

I have a bash script that tests some programs and one of the program returns Segmentation fault so I tried to add a trap in the head of my script: trap "echo 'segfault occured!'" SIGSEGV That ...
3
votes
2answers
589 views

Wrapper program that sets signal handler

I would like to have a wrapper program that runs a given command and sets a signal handler so that it gets run when the command receives a specified signal. The question is this: Is there an ...
3
votes
1answer
3k views

What is signal 0 in a trap command?

I'm following this guide on how to set up passwordless SSH authentication with ssh-agent. To start up ssh-agent the author recommends the following code in .bash_profile: SSHAGENT=/usr/bin/ssh-agent ...
1
vote
1answer
2k views

Can you specify a separate trap in a subshell created with ()?

I'm writing a script that starts a subshell to go off and do some work. In a special case, the script needs to tell the subshell to cleanly stop what it's doing and exit early. However, my ...