Use this tag for questions about the `trap` Bash built-in.
Questions tagged [bash-trap]
171 questions
2
votes
1 answer
Trap bash errors from child script
I am calling a bash script (say child.sh) within my bash script (say parent.sh), and I would like have the errors in the script (child.sh) trapped in my parent script (parent.sh).
I read through the medium article and the stack exchange post. Based…
Vivek Maran
- 2,623
- 5
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2
votes
1 answer
Single statement subshell doesn't seem to inherit ERR trap when using "set -o errtrace"
Consider this minimal example, which I run as an executable.
#!/bin/bash
set -E
trap 'echo "ERR trap triggered"' ERR
(
echo "hello" >/dev/null
ls /root/
)
Notice the two ERR trap messages in the following output:
ls: cannot open directory…
jmrah
- 5,715
- 3
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- 37
2
votes
3 answers
How to trap input to control the screenshot function?
I want to trap input to control the screenshot function.
vim myscreenshot.sh
screenshot(){
ffmpeg -video_size 1920x1080 -framerate 25 -f x11grab -i :0.0+0,0 /tmp/out.mp4
}
close(){
echo "screenshot is over"
exit
}
trap…
showkey
- 482
- 42
- 140
- 295
2
votes
1 answer
Bash trap is not invoked in function called from loop
A trap invoked in a function called from inside of loop is not invoked. A trap works as expected if invoked in loop body directly. Same function, if called outside of loop, invokes trap.
#!/bin/bash
function error_handler()…
Vlado B.
- 75
- 4
2
votes
2 answers
How can I print to stdout from within a trap called during eval
I expected the following script to print This is redirected to 'output'. when I press ctrl+c:
#!/bin/bash
trap_function(){
trap '' EXIT INT TERM
echo "This is redirected to 'output'."
touch this_will_exist
}
trap trap_function EXIT INT…
katosh
- 372
- 4
- 12
2
votes
2 answers
How to handle interrupt signal when reading from stdin in bash
I'm playing around with bash read functionality. I like what I have so far as a simple layer on top of my current shell. The read -e does tab-complete and previous commands, and sending EOF with ctrl+d gets me back to my original shell. Here's my…
CGanote
- 149
- 1
- 6
2
votes
1 answer
How to kill all the sub processes of bash script when it exits?
I am using named pipes to communicate between 3 kind of process: a producer, some readers and some writers. Then I created a script that simply it runs all the process, and I would like that when the run.sh process is killed or it terminates all the…
Alberto
- 2,881
- 7
- 35
- 66
2
votes
1 answer
Bash: Ignore SIGNT (ctrl-c) x amount of times
So, in this program, using BASH, I am trying to ignore or trap CTRL-C multiple times (not infinite) before it takes.
at the moment I know how to ignore the command once.
But I have no idea how to increment or decrement the amount of times it is…
David Walker
- 41
- 1
- 7
2
votes
1 answer
How to use trap to terminate while loop containing ffmpeg fed by redirect from /dev/null?
I discovered here Loop calls process that takes a long time to complete. How do I break out of it? that piping from find to a while loop that calls an ffmpeg cli [HandBrakeCLI] will not process more than one input file because ffmpeg has a quirk…
Lorccan
- 793
- 5
- 20
2
votes
1 answer
Cleaning up after a ruby script -- trapping signals
My ruby script creates a tempfile and spawns an potentially long-running external process. Neither may continue to exist after the script ends, no matter the way in which the script terminates.
I thought the following lines would take care of…
Petr Skocik
- 58,047
- 6
- 95
- 142
2
votes
1 answer
Why does my trap does not work?
I have written below script:
#!/bin/bash
sleep 15
function_signalr()
{
date
date | awk '{printf "%-15s\n", $2}'
}
trap "function_signalr" 10
When I start the process by "process &" it runs, the PID is given.
I do kill -10 PID, but my trap does…
user3214667
- 57
- 1
- 1
- 2
2
votes
1 answer
How to print a message and continue after trap'ing a signal in bash?
I'd like to to do this in bash:
trap "echo Don\'t do that!" 2 3
which works just fine, except that I want the script to continue. How can I do that? If I leave the command as a blank string, the script continues, but does not print anything. Can I…
Johannes Ernst
- 3,072
- 3
- 42
- 56
2
votes
2 answers
how to prevent a bash script called via su -c from hanging after SIGINT
I have two scripts. These are simplified. The root-script.sh calls userscript.sh:
root-script.sh:
#!/bin/bash
su - user1 -c "/user1path/user-script.sh"
user-script.sh:
#!/bin/bash
trap 'echo please use x for exit' 2
while x=0; do
read -p…
Frank
- 21
- 1
- 3
2
votes
1 answer
Trap command in script works when called from CLI but not when used in a PBS job
I have the following simple bash script:
#!/bin/bash
set -o pipefail
set -o errtrace
set -o errexit
PROGNAME=$0
trap 'echo "${PROGNAME} recieved signal EXIT" | mailx -s "EXIT" "someone@anywhere.com"' EXIT
trap 'echo "${PROGNAME} recieved signal…
Polysics
- 40
- 4
2
votes
2 answers
my interactive bash script loop is breaking even if I have a trap INT that should prevent it?
on this simple script
#!/bin/bash -i
trap 'echo "(ctrl+c was hit)"' INT
while true; do
echo -n "hit Enter..";read
echo "still on loop"
done
if I hit ctrl+c it will exit the loop
if I make it not interactive with 1st line like #!/bin/bash,…
Aquarius Power
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