All Questions
37
questions
0
votes
1
answer
28
views
GNU parallel export function output to variables failed
This script is to determine when destination file already exist, source file will update the destination one or be removed according to flag "$dup_act".
#!/bin/bash
dup_chk()
{
# $1: f_src,...
0
votes
1
answer
53
views
Is there a way to export functions with parameters already expanded?
Let's say I have two files main.sh and sub.sh in the same folder with the following contents:
main.sh:
#!/usr/bin/env bash
export PARAMETER="main"
my_func(){
echo "$PARAMETER $1"...
- 3
2
votes
0
answers
64
views
Why `declare -p VAR` returns "declare -- VAR" on an unset local variable but gives an error "bash: declare: A: not found" on an unset global variable?
I don't understand:
$ declare -i VAR=0; \
> echo "$A"; \
> fun() { local -i VAR=1; echo {; echo "$VAR"; declare -p VAR; unset VAR; echo "$VAR"; declare -p VAR; echo ...
- 234
0
votes
1
answer
34
views
files zipped using function not naming correctly
I'm probably missing something basic with bash function variable syntax here.
My understanding of the zip command's syntax is that it's zip newfilename.zip filetobezipped. So I want my function to zip ...
- 3
1
vote
1
answer
189
views
How to display only shell variables (not functions) [duplicate]
How can I display a list of shell variables in Bash, not including functions, which often clutter the output, because of the many related to completion?
I have examined declare, and it has an option ...
- 3,277
2
votes
1
answer
100
views
zsh - How do I make local variables available to inner functions that are not defined with 'eval'?
I have a zsh function that looks like this:
outer_func () {
local LOCAL_VAR='test'
inner_func () {
echo "${LOCAL_VAR}"
}
}
where $LOCAL_VAR is not available to ...
- 401
0
votes
2
answers
41
views
Function can echo the value that has not received as input
I'm new to bash. I'm confused about the way functions work in this language.
I have written this code:
#!/usr/bin/env sh
choice_func() {
echo "$choice"
}
echo "Enter your choice:"
read ...
- 177
1
vote
0
answers
31
views
Variable not available outside function [duplicate]
I'm having difficulties understanding the following example I created.
The variable glob_var gets changed inside the test() function, but the original value remains outside of the function:
test() {
...
- 400
0
votes
1
answer
579
views
How to pass a multiword string as argument in Linux [duplicate]
I am trying to pass a multiword argument in a function an echo the result in a simple fashion.
Currently I am doing this:
function myFunction {
multiWordString=""
for ((i=3; i<=$#; i++...
- 443
0
votes
1
answer
3k
views
Random unbound variable error within function
I made a function in bash and when I call it, it crashes with an unbound variable error. I don't understand cause the variables that are said to be unbound are declared. Moreover, it seems to be ...
- 136
1
vote
1
answer
91
views
Can you help me understand this bash behavior? Background processes and their attachment to the current process
I stumbled upon this unexpected behavior and I was hoping someone with a better understanding could explain it!
I have a function that is called by a script and run as a background process - ...
- 176
0
votes
2
answers
164
views
How can I wrap this checking of variable set/unset into a function?
As https://stackoverflow.com/a/13864829/ said,
$ if [ -z ${aaa+x} ]; then echo "aaa is unset"; else echo "aaa is set"; fi
aaa is unset
can test if a variable aaa is set or unset.
How can I wrap ...
- 89.7k
10
votes
2
answers
2k
views
Can you explain these three things in this bash code for me?
I have a function in my .bashrc file. I know what it does, it steps up X many directories with cd
Here it is:
up()
{
local d=""
limit=$1
for ((i=1 ; i <= limit ; i++))
do
...
- 5,164
1
vote
4
answers
103
views
Pass function argument to defined variable
How can I "inject" a function argument to a defined variable like in this example?
mood="i am $1 happy"
happy ()
{
echo "$mood"
}
happy "very"
Current output:
i am happy
Desired output:
i ...
- 13
0
votes
1
answer
248
views
Shell script: Call variable with parameters/arg
I have the following function in a bash script:
testcur.sh :
#!/bin/bash
function valcurl {
if [[ $1 != "" ]] then
tbl=$2 # can be multiple values
data=/home/data
...
3
votes
2
answers
709
views
Zsh, Indirect array variable assignment without using eval
I have a variable VARNAME which contains a name of another variable. I'd like to assign to this another variable without using eval. How can I do that?
Th reason I don't want to use eval is the ...
- 412
3
votes
3
answers
2k
views
How to assign the success/fail status of a function to a variable in Bash?
I know that a way to do it is :
# run a command here, like [[ $A == *"ABC"* ]]
result=$?
if (( result == 0 ))
then
result=true
else
result=false
fi
Then I can do :
if $result
then
...
Is there ...
-1
votes
2
answers
286
views
When is a variable local and when global?
Consider the following two functions:
f1() {
if [ "$a" == "" ]; then
a="0";
else
a=$(($a+1));
fi;
echo "$a";
}
f2() {
echo "f1(): $($1)";
}
If I call f1 multiple times a will be ...
- 1,151
4
votes
1
answer
4k
views
Bash local variable initialization
How does Bash initialize local variables? Will the following commands always do the same thing (when used inside a function)?
local foo
local foo=
local foo=""
- 3,744
1
vote
1
answer
379
views
How to know where shell variables and functions are set?
When I type the set command in my system I've got this extract out :
__colormgr_commandlist='
create-device
create-profile
delete-device
delete-profile
device-add-profile
...
- 1,288
1
vote
1
answer
2k
views
How to use ssh in a function(bash)?
I am trying to execute few commands in a server by logging in using sshpass command like below.
SSH_ARGS='-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -q'
sshpass -p 'password' ssh ${...
- 882
1
vote
1
answer
410
views
Declare as local var will break a function and log out "1: number expected"
function projectopen {
local di_files=(*.xcworkspace */*.xcworkspace *.xcodeproj */*.xcodeproj)
# open first exsit file
ls -d -f -1 $di_files 2>/dev/null \
| head -1 \
| xargs ...
- 235
8
votes
1
answer
1k
views
Circular name references in bash shell function, but not in ksh
I'm writing a set of shell functions that I want to have working in both Bash and KornShell93, but with Bash I'm running into a "circular name reference" warning.
This is the essence of the problem:
...
- 267k
1
vote
1
answer
267
views
Func name as variable in loop
Overview:
I save my variable in a config file and call them later.
Each entry with the name FailOverVM has a number beside it like FailOverVM1 and I want to check to see if it has data and generate a ...
- 13
2
votes
1
answer
739
views
Save return value from a function in one of its own parameters
This is what I want to achieve:
Function:
Func1() {
$1="Hello World"
}
Call function:
local var1
Func1 var1
echo $var1 (should echo Hello World)
I found this example which seems to work, but ...
- 530
50
votes
4
answers
67k
views
Scope of Local Variables in Shell Functions
After reading 24.2. Local Variables, I thought that declaring a variable var with the keyword local meant that var's value was only accessible within the block of code delimited by the curly braces of ...
- 601
4
votes
1
answer
3k
views
how to get or reflect the name of the bash function which is called? [duplicate]
i did not yet found a solution to this. Anyone a hint?
i sometimes write bash functions in my shell scripts and i love to have my scripts being verbose, not just for debugging. so sometimes i would ...
- 879
1
vote
1
answer
183
views
Which shells have functions where "local" does not alter exported variables for child processes?
In the example below, an exported variable is re-set as local in a function. Bash, Zsh, Fish don't pass on the original value to the child process. Are there any shells that make local affect the ...
- 739
15
votes
3
answers
63k
views
How to increment local variable in Bash?
Data
1
\begin{document}
3
Code
#!/bin/bash
function getStart {
local START="$(awk '/begin\{document\}/{ print NR; exit }' data.tex)"
echo $START
}
START2=$(getStart)
echo $START2
...
- 6,308
0
votes
3
answers
3k
views
Returning local values from Bash variables?
I studied this article called Returning Values from Bash Functions.
Data
Lorem.
\begin{document}
hello
\end{document}
Case #1 which does not work
Code
#!/bin/bash
function getStart {
...
- 6,308
9
votes
4
answers
14k
views
How to use call-by-reference on an argument in a bash function
I am trying to pass a "var name" to a function, have the function transform the value the variable with such "var name" contains and then be able to reference the transformed object by its original "...
- 95
1
vote
1
answer
1k
views
Why doesn't my function work with spaces? (cd, dirname) [duplicate]
I have had this function I use it very often and it works fine.
Here it is:
cdx () { cd `dirname $1` ; }
However, this does not work with spaces. When I use it like this for example
cdx ~/desktop/...
- 10.6k
4
votes
1
answer
7k
views
How do I define alias with variables which can be changed at runtime?
This is probably a very easy to answer question, but I could not find any questions already asking this due to different wording when writing titles.
Running help alias on my bash prompt returns only ...
- 10.6k
0
votes
1
answer
4k
views
Value assigned inside a function variable is always empty
I have the following simple script. In this script, I am assigning a value to a global variable inside a function. I can clearly see that the value is being assigned to the variable via a debug ...
- 963
2
votes
2
answers
368
views
Nature of the positional parameters
I wrote this shell script which sort of confused me a bit...
function func
{
the variables received are
echo $0: $1 and $2
}
echo in the main script
func ball boy
The name of script is shell.txt I ...
- 345
0
votes
2
answers
123
views
Why must you be careful when using Bash's built in command history function to re-run previous commands that contain variables?
I know !! re-runs commands but what exactly would occur if I re-ran a command that had a variable in the command?
- 205
4
votes
4
answers
5k
views
Scope of variables when calling function from find
In a bash script I define a function that is called from find. The problem is that the scope of variables does not extend to the function. How do I access variables from the function? Here is an ...
- 553