Questions tagged [exit-status]
Use this tag If your question revolves around determining or utilizing the exit status (return code) of a command. Common syntax involves the $? variable and the && and || symbols.
274
questions
0
votes
2
answers
38
views
How to capture exit code of subshell (while in pipe)
somefile contains this:
aaa
bbb
ccc
This is the subshell which can exit before completing all iterations. In my particular case is while but it could be for or until:
cat "somefile" | while ...
- 267
0
votes
1
answer
47
views
Evaluating exit code of pipe or fifo
So i have something along the lines of:
set -eo pipefail
ssh localhost "ls; exit 1" | cat > output
I thought pipefail would prevent cat to write to ouput (because of the exit code from ...
- 103
1
vote
2
answers
53
views
Ensuring Distinguishable Exit Codes for Shell Scripts
Say I have two shell scripts, a.sh and b.sh, where a.sh calls b.sh somewhere inside. Then, say that b.sh could exit with exit codes 0, 1, or 2.
What are some techniques that can be employed to ensure ...
- 113
2
votes
1
answer
104
views
Detect if the previous line was a command or not
I'd like to enable Windows terminal shell integration in bash. (Don't judge me.) One nice feature is that the terminal can show a mark in the scrollbar for each command, with a color depending on ...
- 230
0
votes
1
answer
65
views
Does there exist a tar implementation that exits 0 when an error occurs?
Vim runtime commit 3d37231437fc0f761664a7cabc8f7b927b468767 tries to fix a tar-editing plugin by removing the assumption that a filename doesn't contain the words warning, error, inappropriate or ...
- 522
1
vote
1
answer
506
views
zsh: check exit code of pipeline of commands
I have long pipeline of commands in zsh script:
pv /dev/sda > sda.raw | sha256sum > sda.raw.sha256 | cut -c61-64 | read SHASUM
how can I check inside an if statement, that all commands exited ...
- 728
0
votes
1
answer
121
views
Calling a script from within csh with output redirection
What I would want:
#!/bin/csh
# call /myscriptpath/myscript.any and redirect 2>&1 and get retval and output
set my_msg = `/myscriptpath/myscript.any`
set my_ret = `echo $?`
How to capture the ...
- 238
3
votes
2
answers
123
views
How and why does using redirection or writing files within an if statement affect exit code?
In zsh
echo 'a string' > test.txt
echo $?
0
and
[[ $(echo 'a string') ]]
echo $?
0
whereas
[[ $(echo 'a string' > test.txt) ]]
echo $?
1
another example
curl -so 'curl-8.2.1.tar.gz' https://...
- 33
0
votes
3
answers
601
views
Does `return 0` equal `true` (in sourced script to shell's environment)?
I am working on a highly portable script that users shall source to their shells, forcing me to use POSIX scripting.
There are many useful functions in the script, one of them is special though, as ...
- 29.3k
6
votes
2
answers
689
views
Why does `trap` passthough zero instead of the signal the process was killed with?
Consider the following:
#!/bin/bash
trap 'echo $?' INT
kill -INT $$
Output: 0
Here I would expect 130 for my system. Of course, if I do a Ctrl + C then I get 130.
The same thing happens for any ...
- 193
0
votes
1
answer
530
views
Negate exit status of process
In a project, I have a test setup where I read the exit status $? of a command.
In my test, I want to ensure that the string foobar is not present in the output.
When I run the command:
./program | ...
- 103
0
votes
2
answers
937
views
Get exit status of the first command in a pipeline *in the second command*
My question is similar to Get exit status of process that's piped to another, but I want to get the exit status of the first command in the pipe within the pipe.
Here's an example:
false | echo &...
- 103
-1
votes
2
answers
1k
views
systemctl can't find executables while root can?
Strange thing: I've created a service, that should start a springboot fat archive webserver.
Service:
#!/bin/bash
[Unit]
Description=JalouWeb
[Service]
Type=simple
WorkingDirectory=/opt/jaloucontrol
...
- 9
1
vote
1
answer
481
views
Getting first line of piped output sets exist status 141 which fails bash script with set -eo pipefail
I have a bash script that runs a command from which I want to get only the first line of output.
The obvious answer is some_command | head -1, right? Well, this works 99% of the time, but when the ...
- 486
0
votes
1
answer
1k
views
Make systemd treat unexpected exit as failure
I'm wrapping a 3rd party executable in a systemd service unit to manage it. I can't alter the behavior of this program and I don't really trust its exit codes. I would like to treat any exit that ...
- 692
2
votes
1
answer
268
views
Using set -e (errexit) with block of commands and executing another on fail of that block (SC2181)
I just found out about set -e as I was searching for an answer to "how to run many commands (without &&) and immediately stop on non-zero exit code of any of them?". The set -e was ...
- 151
11
votes
1
answer
988
views
Why does the "dc" command exit(1) when using q(uit)?
$ echo "$?"
0
$ echo 'q' | dc || echo "$?"
1
Why is using q to quit dc considered an error?
(The test was run on Ubuntu 20.4.)
- 446
4
votes
2
answers
2k
views
How to print the failed command that caused the script's failure?
I'm using the -e flag.
Usage:
#!/bin/bash -e
Explained:
-e Exit immediately if a simple command (see SHELL GRAMMAR above) exits with a non-zero status
When a command in the script fails, the ...
- 561
1
vote
1
answer
613
views
How might I only write stdout to file if exit code is 0?
The sponge command "soak[s] up standard input and write[s] to a file", which lets us pipe from and to the same file. I want to do something similar, where I pipe to a sponge-like utility, ...
- 123
1
vote
1
answer
2k
views
error handling in a bash subshell
I'm writing some bash code, and I'd like the script to exit if there's any error. The set -e trick works pretty well, but not with subshells. Here's a simplified example:
set -e
chmod a=r file.txt
x=`...
- 121
1
vote
2
answers
352
views
How to make a script fail when there is an error in here string?
I have a script similar to this:
#!/bin/bash
set -euo pipefail
IFS=$'\n\t'
while read -r l; do
echo "${l}"
done <<< "$(cat input.txt)"
echo Success
The command cat ...
- 123
2
votes
1
answer
925
views
How to suppress the impact of 'File system loop detected' warnings on the exit status of the 'find' command?
I use find command to find all regular files older than some number of minutes in a directory tree containing some symbolic links that need to be resolved:
find -L . -type f -mmin +300 -print
But ...
- 216
0
votes
2
answers
86
views
Bash IF statement is not behaving as expected
I cannot understand the logic of what's going on with this simple Bash script:
#!/bin/bash
# Check if file is present
which ./vendor/bin/non_existent_file &> /dev/null
printf "Exited ...
- 113
2
votes
1
answer
334
views
I want to understand the intuition of the output
bash-3.2$ echo foo > foo.txt
bash-3.2$ if cmp foo.txt foo.txt; then echo EQUAL; fi
EQUAL
bash-3.2$ echo bar > bar.txt
bash-3.2$ if cmp foo.txt bar.txt; then echo EQUAL; fi
foo.txt bar.txt differ:...
- 4,282
1
vote
1
answer
349
views
test returns wrong value (but no errors) depending on the presence of spaces around the operator
If there are spaces around the operator, test returns the correct value of the expression.
But if there are no spaces, it doesn't throw any syntax error and always return true.
$ test "A" == ...
- 317
2
votes
1
answer
103
views
Return value inside unbuffer command
I have the following bash code to capture the result of a build while printing the output to the screen and provide parsing of the build results.
output=$(unbuffer cmake ... | tee /dev/tty)
...
- 23
1
vote
2
answers
3k
views
Shell script exit codes
I have a question about bash exit codes. Can I basically define what each code I return means? If so is there some standard way of defining or documenting that?
I've been looking into it and I see ...
0
votes
2
answers
436
views
Can sed execute a command on empty file (quit command)
I have a shell script in which I want to validate the content of a file.
The expected content should have a specific first line, say ^MYFIRSTROW, and not be empty.
So I wrote this check using GNU sed :...
- 619
8
votes
2
answers
960
views
Is there a pipefail equivalent for dash?
I have a perl script that runs a system() call to execute shell commands and I would like to run more than one command and pipe data between them. Something like (in perl):
system("command1 | ...
- 245k
0
votes
0
answers
2k
views
collect 2: error: ld returned 1 exit status when compling
I'm trying to install xschem on a remote computer (centos 7).
I ran ./configure and it was successful (i.e. no missing packages)
However when I'm trying to run make in the same directory I get:
/cs/...
0
votes
1
answer
714
views
What does systemd exit code EXIT_FDS mean?
I get this message from systemd status after I have stopped my service:
Actice: failed (Result: exit-code) <...> Main PID: 4747 (code=exited, status=202/FDS)
Status FDS is defined in the docs ...
- 177
14
votes
3
answers
19k
views
Print exit status code after each command in terminal
I would like to print at every lauched command in zsh exit code value.
E.g.
$ cat file_not_present
cat: file_not_present: No such file or directory
Exit code 1
I only know that I can print error code ...
- 151
4
votes
1
answer
38k
views
Systemctl service failed Exit-code
My systemctl Code dont work
● <appname>.service
Loaded: loaded (/etc/systemd/system/<appname>.service; disabled; vendor prese
Active: failed (Result: exit-code) since Mon 2022-04-04 ...
- 43
0
votes
1
answer
428
views
grep: if input file is also the output, then why clearing the input file? [duplicate]
Scenario:
$ cat t0.txt
xxx
$ grep xxx t0.txt > t0.txt
grep: t0.txt: input file is also the output
# exit status 2
$ cat t0.txt
<nothing>
Question: if input file is also the output AND the ...
- 629
2
votes
1
answer
1k
views
Bash named pipes, parallel commands and exit status
I'm trying to use a named pipe so I can keep stdout for status output from a long process. I could use stderr for status output, but I'd like to keep that for errors. Here is an example:
#!/bin/bash
...
- 653
0
votes
2
answers
3k
views
Exit bash script if a command succeeds
I have some simple smoke test scripts that generally look like:
set -e
run-command
run-other-command
echo ok
This works great when I expect commands to succeed; if any fails, the set -e will exit ...
- 103
0
votes
0
answers
262
views
Why does this conditional statement, based on exit code, work in the reverse of what is expected? [duplicate]
The script is test.sh.
#!/bin/sh
if cmp -s file.a file.b; then
echo diff
else
echo same
fi
When checking the exit code from cmp -s I see:
When file.a and file.b are different.
cmp -s file.a file....
- 161
0
votes
2
answers
2k
views
Why the Unix command exit with non-zero value in Shell and evaluates to True when used in bash if condition?
The command patch -R -p0 -s -f --dry-run < abc.patch fails with exit code 1 and prints a error message from patch command but when used with negation in a if condition it passes (i.e prints Pass), ...
0
votes
1
answer
2k
views
Reboot and relaunch a script if error
I have a script (not written by me, I cannot modify it) that has to run for days, that sometimes fails (exits with an error).
In this case all I have to do is just reboot the server (there is no ...
- 2,581
1
vote
0
answers
871
views
TAR returns 1 on big directories - how to ignore this?
I'm running the following sequence for backup purposes:
$> set -o pipefail
$> tar -c /vary/large/folder1 /very/large/folder2 | xz ... | gpg ... | aws ...
$> echo "${PIPESTATUS[0]} ${...
- 2,493
8
votes
0
answers
1k
views
How to tell systemd to start a service after a clean exit of another service
I'm trying to start a systemd. service after another service exits properly (e.g : in a application it could be exit(EXIT_SUCCESS) ).
I've seen that there might be an OnSuccess option in the later ...
5
votes
1
answer
2k
views
When does inherit_errexit not work?
#!/usr/bin/env bash
set -e
shopt -s inherit_errexit
a=$(cat no-such-file)
echo survived
$ /tmp/a.sh
cat: no-such-file: No such file or directory
#!/usr/bin/env bash
set -e
shopt -s inherit_errexit
...
- 3,473
2
votes
1
answer
333
views
zsh pipestatus disappears in the following prompt
I am on zsh 5.8 (arm-apple-darwin20.2.0). Unlike the way PIPESTATUS in bash is available to read during the next shell prompt, pipestatus of pipe in zsh seems to disappear in the following prompt.
❯ ...
- 606
1
vote
0
answers
17
views
Catch the root command exit code from a regular user [duplicate]
I've been researching umount exit codes for some error cases, running the following command repeatedly:
$ sudo sh -c "umount /home; echo $?"
And got surprisingly strange results. The error ...
- 111
3
votes
1
answer
2k
views
pdsh and command exit code
I would like to use pdsh to assert that a command successfully run on multiple nodes, if the command fails on any nodes the exit code (from pdsh) should be non-zero.
Consider the following examples:
$ ...
- 133
3
votes
1
answer
4k
views
Exit sh script if condition is met
Maybe this is a rookie question, but I am fairly new to sh scripting and I have to wait about two hours to make sure my logic is right, so I just wanted to ask here.
I have a sh-script which should ...
- 143
10
votes
1
answer
903
views
Why 'let' exits with code 1 when calculation result equals to 0?
I came across this question whose author had dealt with problem caused by:
let x=1-1 exits with code 1.
According to bash manual:
If the last expression evaluates to 0, let returns 1;
otherwise 0 is ...
2
votes
1
answer
403
views
Difference between if [ ... and test ... statement in bash
Consider the following:
echo "hello" > file.txt
is_match1 () {
local m
m=$(cat "file.txt" | grep -F "$1")
if [ -z "$m" ]; then
return 1
fi
}
...
- 449
5
votes
2
answers
2k
views
BASH: Change exit status in trap
Can I assign a different exit status to a shell script in a trap handler?
Through trial-and-error, I found that calling exit in trap the exit status can be changed. Normal commands, whether fail or ...
- 505
1
vote
1
answer
1k
views
zsh: How to store the return code of a statement without triggering `set -e`?
Suppose I want to capture the return code of
(exit 56)
If I use set -e or a zerr handler, I can no longer do:
(exit 56)
ret=$?
If I use (exit 56) || true to avoid set -e, the return code would ...
- 1,640