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2
votes
4answers
36 views

How to catch and handle nonzero exit status within a Bash function?

Say I have the following (pointless) Bash function: myfunc() { ls failfailfail uptime } I run it as follows: myfunc || echo "Something is wrong." What I want to happen is ls runs (as ...
2
votes
1answer
33 views

How do I check for the existence of a process without a failed exit code being returned?

I’m using Amazon Linux. I want to start a process provided one isn’t running already. This is a bash script I embed within a Jenkins Maven job. So I have pids=$(pidof /usr/bin/Xvfb) if [ ! -n ...
4
votes
0answers
4k views

Proper usage of EXIT & ERR traps in bash scripts [closed]

I'm working on a bash script and as I've been going I've learned about traps, signals, function return codes and other such features I've not previously used. I may be thinking about things ...
2
votes
1answer
454 views

How to have a bash script perform a specific action on errors of _each_ command?

Similarly to set -e performs an exit on "uncaught" $? != 0, I'd like to have this event trigger the execution of another command, e.g. a logger call. How can this be done?
1
vote
2answers
3k views

PHP exec command has the result 0 even if an error occurs

I have this PHP code: $execout=exec('ssh root@xxx.xxx.xxx.xx "sudo /etc/init.d/smokeping reload"',$output1,$result); if($result !=0){ echo"that can't reload"; } else{ echo "successfully ...
0
votes
0answers
19 views

check if a variable contains letters and exit if true [duplicate]

I am using the line below to verify that an argument do not have a letter. If it have, the script will exit. Can you help me on how I can exit the script if the argument have a letter? echo $1 | ...
131
votes
15answers
53k views

Get exit status of process that's piped to another

I have two processes foo and bar, connected with a pipe: $ foo | bar bar always exits 0; I'm interested in the exit code of foo. Is there any way to get at it?
1
vote
1answer
32 views

Duration of /proc/pid/stat

I have a process that starts a child process and when the child exits, scans /proc/<pid>/stat to gather some information about the CPU and memory the child used. However I am worried that I am ...
3
votes
3answers
65 views

When interrupting a process, does a memory leak occur?

Lets say I created a program in c/c++, where I manually allocated some variables. Then while running the program, I send an interrupt signal (Ctrl-C). Are those variables freed from memory, or will ...
0
votes
0answers
66 views

Custom interrupt handler for bash scripts [duplicate]

I'm writing a script that needs to keep track of all backgrounded processes it launches: index=0 for i in `ls $TOPOLOGY_FILE_PREFIX*` do if [ ! -z "$11" ]; then ./noc_sim.sh ...
0
votes
1answer
13 views

Less quit behavior

I'm not sure how to describe this but I'll try by comparing it to vi. When I open vi, do something, and then exit vi it brings me back to the terminal where I can see all of the commands I had ...
0
votes
1answer
35 views

My if bash script always execute the break

I`m making a script to rename files in a folder. The new name for the files is in a config file. I have to be sure that the file I want to rename corresponds to the current one in the config file. My ...
3
votes
1answer
67 views

Why does the exit code of a script appear to have a different value than what is returned?

I have a script (run-docker-container.sh) that calls another script (create-docker-container.sh). create-docker-container executes a curl script against the docker remote api and returns the http code ...
1
vote
3answers
94 views

Where is `exit` defined?

Suppose I want a bash command to do something extra. As a simple example, imagine I just want it to echo "123" before running. One simply way to do this would be to alias the command. Since we ...
0
votes
2answers
29 views

Why is the exit status always 0 at the start of a script?

I have a script like this, named judge: #!/bin/bash echo "last exit status is $?" It always outputs "last exit status is 0". Eg: ls -l; judge # correctly reports 0 ls -z; judge # incorrectly ...
0
votes
2answers
42 views

exit code of the command **before** last? [duplicate]

I'm running a script within a script, release.sh and caller.sh (caller.sh calls release.sh). Both are bash. release.sh contains a bunch of conditions with 'exit 1' for errors. caller.sh contains a ...
0
votes
1answer
24 views

Function does not get called and script exits

So i got the function RM_OBJ_P which gets called from the menu page PAGE_RM. This is working, you can enter all the funky filenames you know and if they are in the database, the output gets printed ...
4
votes
1answer
81 views

bash does not exit on abnormal exit of child process due to signal

I try really hard to understand what I am doing wrong and why? I have a launch.sh script which launches process.sh. launch.sh #!/bin/bash while true; do ./process.sh done process.sh ...
0
votes
4answers
120 views

bash : multiple command on one line with different exit code

I run a bash command from a c++ code using the system function provided in cstdlib. My question is not about the c++ implementation, but the one thing that is relevant to my question, is that I have ...
4
votes
3answers
709 views

How to write an abort-on-error script without adding `|| exit $?` to every line?

I'm writing a bash script that should exit the error code of the last failed command and not continue execution. This can be achieved by adding a || exit $? everywhere, but is there an easier way, ...
1
vote
3answers
146 views

How to force ssh connection to exit at end of script

I have a script which is composed of two parts. part1 creates an ssh connection, part2 runs a script (about 800 lines and counting so far). part1: ssh $target_server "bash -s" < $target_script ...
28
votes
2answers
5k views

Why does ( echo “”; exit 1) not exit the script?

I have a script, that does not exit when I want it to. An example script with the same error is: #!/bin/bash function bla() { return 1 } bla || ( echo '1' ; exit 1 ) echo '2' I would assume ...
0
votes
1answer
372 views

How to terminate cat command within a shell script

I wrote a shell script that uses cat and tr commands to generate a file. My shell script looks like #!/bin/bash printf "generating random file > plaintext \n" cat -v | tr "a-z" "b-y" < ...
2
votes
3answers
130 views

How to wait for all spawned and backgrounded processes to finish in bash script

I've looked and looked and can't find a working solution to a bash script I'm trying to create to shut a process down and wait for it and spawned processes to finish. I'm still learning a lot of ...
4
votes
3answers
2k views

How do I get the list of exit codes (and/or return codes) and meaning for a command/utility?

Is there a way I can do what stated in the title from the terminal commands, or will I have to look into the codes?
1
vote
1answer
32 views

Retrieve data from mem cache

Newbie to Linux. My application writes to a log file and for some reason it stopped writing to that file suddenly. We have restarted the application to fix this glitch. Is it possible to retrieve the ...
11
votes
6answers
1k views

Using “reserved” codes for exit status of shell scripts

I recently came across this list of Exit Codes With Special Meanings from the Advanced Bash-Scripting Guide. They refer to these codes as being reserved and recommend that: According to the above ...
1
vote
2answers
110 views

How to stop bash scripts from exit ing the window altogether

When I write bash script and I have exit;; or exit 0;; the script not only exits but the window (or pane in the case of tmux panes) exits completely (goes away). e.g. while true; do read -p ...
0
votes
1answer
46 views

Idiomatic bash way to run optional action without side effects on exit code

This script will exit with test result which is not desired from callers perspective. How it should be implemented instead? #!/bin/bash test -n "" && echo "test passed"
3
votes
2answers
1k views

wait does not wait

If i have a file called myprogram containing sleep 200 date Run this in the background: $ sh myprogram & i want to know when myprogram has completed by using wait command $ cat >notify ...
5
votes
2answers
393 views

Keep exit codes when trapping SIGINT and similar?

If I use trap like described e.g. on http://linuxcommand.org/wss0160.php#trap to catch ctrl-c (or similar) and cleanup before exiting then I am changing the exit code returned. Now this probably ...
4
votes
2answers
1k views

Removing zombie process from the process table

Can somebody please explain when parent process receives the exit status of a dead child process via wait, who actually reallocates the memory of the child process and removes it from the process ...
0
votes
1answer
137 views

Skip 'natural' exit in trap

How are you? My script looks like: trap "$(pwd)/dd-destroy.sh $l-env;$(pwd)/dd-drop.sh $l-db;exit" INT QUIT TERM EXIT ./dd-all.sh $l $l-db $l-env || exit 1 app_ip=$(./dd-status.sh ip $l-env|grep ...
7
votes
3answers
10k views

reliable return code of background process

Let's assume the following piece of bash code: foo > logfile 2>&1 & foo_pid=$! while ps -p$foo_pid do ping -c 1 localhost done wait $foo_pid if [[ $? == 0 ]] then echo "foo ...
2
votes
2answers
150 views

When does a process terminate in UNIX?

At which moment a process in Unix is terminated? Is it necessary a command such as exit(0) or return 0 to be written in a program to terminate a process? My question is provoked by the following code: ...
0
votes
1answer
90 views

What's wrong with exit command on my terminal?

I'm using Linux Mint 17.2 Cinnamon, and I'm a beginner, just switched over from Win10. Somehow, the exit command isn't working, could somebody help me out?
8
votes
4answers
3k views

New parent process when the parent process dies

In UNIX, when a parent process disappears, I thought that all child processes reset init as their parent. Is this not correct all the time? Are there any exceptions?
2
votes
3answers
103 views

Why does using pipe '|' terminate the second process, is there a way to prevent it?

Just to give some context, I'm trying to run this command echo "set hive.execution.engine=tez;" | hive hive terminates as soon as "set hive.execution.engine..." has been entered into the hive ...
11
votes
4answers
7k views

exit shell script from a subshell

Consider this snippet: stop () { echo "${1}" 1>&2 exit 1 } func () { if false; then echo "foo" else stop "something went wrong" fi } Normally when func ...
2
votes
1answer
309 views

What does exit code 130 mean for postgres command?

When attempting to start PostgreSQL server using the /usr/pgsql-9.2/bin/postgres command I get an exit value code of 130. However I could not find any documentation for the exit codes of this ...
1
vote
1answer
102 views

Awkward awk exit code

I'm writing some awk scripts for data validation. These are intended to be selected and invoked by another proces which needs to see the exit code from the awk script to determine if the content was ...
0
votes
1answer
69 views

Bash exit from subcommand [duplicate]

I have a script with the following code: command_that_could_fail || (echo "command failed"; exit 1) However, the exit seems to just be exiting from the sub-command formed by the second part of the ...
4
votes
2answers
200 views

Run an app with a window manager behind in a separate X server

I want to launch an app in a separate X server. It needs a window manager behind it, though. I created a script #!/bin/sh x-window-manager & my-gui-app and launched it with xinit ...
2
votes
1answer
224 views

capture exit status from screen

I have a long-running command that I've been running in screen so as to be able to interact with it when it encounters bugs. But I'd also like to be able to start it via another shell script (which ...
2
votes
2answers
950 views

Call a script for another script, but don't exit the parent if the child calls exit

first.sh: #! /bin/ksh echo "prova" . ./second.sh echo "ho lanciato il secondo" . ./third.sh echo "ho lanciato il terzo" second.sh: echo "sono nel secondo script" dosomething1 exit $? If ...
1
vote
2answers
150 views

How do i have my script execute one more command after a previous command returns a non-zero value before it is aborted?

I have a shell script that calls on a Perl script to do some file processing. The Perl scripts exits with either a zero or one value. I have the Unix set -e command at the beginning of my script to ...
0
votes
2answers
346 views

breaking out of command loop but exit code not the reason?

I run the following: echo "while emacs;do echo $?;done;echo Exit code: $?;" | bash If I exit emacs through the menu or the close button, it prints exit code 0 and restarts. If I exit emacs through ...
4
votes
3answers
4k views

Exiting a shell script with nested loops

I have a shell script with nested loops and just found out that "exit" doesn't really exit the script, but only the current loop. Is there another way to completely exit the script on a certain error ...
1
vote
2answers
316 views

Shell script exit code and logging

I have got following simple shell script, in which I am trying to send STDERR & STDOUT to both screen and log it in a file(test.log). Also, while exiting I am trying to exit with appropriate exit ...
2
votes
2answers
1k views

Negate exit code without using shell features

Is there any standard command that will negate the the exit code of another command provided as an argument without using shell features, or starting a shell? I have a program that does something ...