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.
582 questions
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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 ...
- 128k
0
votes
1
answer
59
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
195
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
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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
272
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 ...
- 1,386
7
votes
1
answer
594
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
211
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 ...
- 3,792
3
votes
1
answer
609
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
183
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
335
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
392
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
97
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
48
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
...
- 4,192
1
vote
1
answer
2k
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How to get function keys working on a Yunzii keyboard?
I have a Yunzii B705 keyboard. It has a row of multimedia keys that double as the function keys. Neither the multimedia nor function keys can work. I don't care about using the multimedia functions, ...
- 4,207
0
votes
4
answers
830
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return value of a function
Can somebody explain me, why the return value of a bash function is always echoed in the function and then consumed by my_var=$(my_func arg1 arg2 ..), when i look through code examples.
my_func ()
{...
- 390