Questions tagged [function]
Questions on function usage in the context of Unix & Linux (mostly but not exclusively shell scripts). Questions on programming in Python, Perl, Ruby, etc. should be asked on Stack Overflow.
584 questions
0 votes
0 answers
36 views
Cannot understand variable assignment logic in bash function [duplicate]
I created this function, which is supposed to allow an interactive selection of an mDNS hostname, and then connect to it via ssh. Yet, whatever I try, the host variable is only available in side the ...
- 175
2 votes
1 answer
111 views
Bash: function in a script with flags
Using https://stackoverflow.com/a/7948533/31298396, we can implement flags for a script testing as follows: #!/bin/bash # Flags # Source: https://stackoverflow.com/a/7948533/31298396 TEMP=$(getopt ...
- 145
3 votes
2 answers
176 views
Localising variables in /bin/sh functions
POSIX defines shell functions as: fname ( ) compound-command [io-redirect ...] The compound-command is further defined as either: ( compound-list ) { compound-list ; } In particular POSIX notes for ...
- 129k
0 votes
1 answer
81 views
How to keep a local function private in a zsh `autoload` module?
I want to define a helper function in a zsh autoload-ed module. The problem is, if I just define in my my_autoloaded_fn file such as function helper { # ... } helper a helper b the name helper ...
- 1,776
2 votes
4 answers
228 views
Is there a Bash variable containing the name of the previously executed function?
I want to line up a couple of Bash functions based on the success or failure of the execution of the preceding function. If something fails, I want to print an error message: function_x has failed. ...
- 287
0 votes
0 answers
33 views
Why is set -e also ignored for functions called via command substitution [duplicate]
I've seen questions about this topic, but they talk about constructs like if or ||. I don't understand why the same behavior seem to happen for substitution ($())? $ my_function() { echo "the ...
- 325
4 votes
1 answer
316 views
Run in background avoiding any job control message from the shell [duplicate]
Lets define a shell function (here the shell is Bash) and test it $ s () { xterm -e sleep 5 & } $ s [1] 307926 $ [1]+ Done xterm -e sleep 5 $ With my specific meaning of ...
- 1,406
7 votes
1 answer
622 views
bash - how to remove a local variable (inside a function)
I've read what's listed in Bibliography regarding unset, declare, local and "Shell Functions". My version of Bash is GNU bash, version 5.1.16(1)-release (x86_64-pc-linux-gnu) var='outer' ...
- 185
2 votes
1 answer
241 views
Why does a 'pipe-to-awk' behave differently inside a function?
I'm using alsa to fiddle around with the volume on a Bluetooth speaker I have connected. It's a 1-speaker setup; just something to provide some background. I can 'get' the volume setting fm the CLI as ...
- 3,928
3 votes
1 answer
648 views
Strange variable scope behavior when calling function recursivly
EDIT: sorry. this is my first question here. Here is a minimal working example #!/bin/bash # count=0 function something() { if test -f "$1"; then # is a file ((count++)) ...
- 43
-1 votes
1 answer
218 views
Override tr in ~/.bashrc
I'm trying to create a function to translate words via a custom script: function mean() { ~/scripts/translate.sh $1 } I would prefer the function to be named tr, as it is much shorter and faster ...
- 23
3 votes
1 answer
372 views
How to overload / customize bash (or any other shell) commands handler?
When in bash some non existing command is run, corresponding error message appears: $ non-existent-command non-existent-command: command not found Is it possible to customize this behavior? I would ...
- 297
3 votes
2 answers
409 views
how to alias the `history` function in fish shell
I'm trying to set the fish history pager to be bat -l fish for syntax highlighting. (i.e. set the PAGER environment variable bat -l fish just for the history command). I tried: # 1: alias history &...
- 149
0 votes
2 answers
123 views
Bash scripting: When to use variable, when function?
basic, innocent question: In bash scripting, why ever using a function, if one can set a variable containing command substitution with the essence of the function - a certain command or set of ...
- 213
2 votes
0 answers
49 views
Can't unalias then redefine as a function in the same conditional [duplicate]
Here is a simplified implementation of an issue in my bash/zsh aliases file: alias foobar='echo bar' # this is out of my control if true; then unalias foobar echo we got inside the conditional ...
- 4,202