parameter-expansion Questions
3
Solved
I try to substract the first string before a dot (.) in bash.
For instance:
1.2.3 -> 1
11.4.1 -> 11
I used the following command based on the docs:
s=4.5.0
echo "${s%.*}"
But it oupt...
Monomania asked 22/11, 2016 at 9:40
2
Solved
I'm trying to port some code from bash 5.1 to 4.2.46. One function which tries to strip color codes from a specifically formatted string stopped working.
This is a sample string text in such format...
Broch asked 5/1, 2022 at 0:44
3
Solved
I got the following variable:
set location "America/New_York"
and want to display only the part before the / (slash) using fish shell syntax.
Expected result
America
Bash equivalent
Using...
Lumumba asked 9/12, 2015 at 20:16
5
Solved
I am having trouble remembering which one of the parameter expansions ${var%subst} or ${var#subst} remove from the front and which one from the back of the string. Example:
$ var=/a/b/c
$ ech...
Countertenor asked 1/3, 2021 at 11:39
2
Solved
Say I read some data into a Bash array:
$ IFS=" " read -a arr <<< "hello/how are/you iam/fine/yeah"
Now, I want to print the first /-sliced field for each element in the array.
What I ...
Waiwaif asked 8/6, 2016 at 9:11
2
Solved
I am after a pure bash solution to "slugify" a variable and that is not as ugly as mine.
slugify: lowercased, shortened to 63 bytes, and with everything except
0-9 and a-z replaced with -. No ...
Gramps asked 1/11, 2017 at 8:6
3
Solved
For debugging my scripts, I would like to add the internal variables $FUNCNAME and $LINENO at the beginning of each of my outputs, so I know what function and line number the output occurs on.
foo...
Paracasein asked 25/5, 2018 at 21:30
2
Solved
In the following block of code, how are line# 3 and 4 evaluated?
for f in "${CT_LIB_DIR}/scripts/build/debug/"*.sh; do
_f="$(basename "${f}" .sh)"
_f="${_f#???-}"
__f="CT_DEBUG_${_f^^}"
done
...
Euridice asked 11/7, 2019 at 23:24
4
Solved
What is the correct way to call some command stored in variable?
Are there any differences between 1 and 2?
#!/bin/sh
cmd="ls -la $APPROOTDIR | grep exception"
#1
$cmd
#2
eval "$cm...
Electric asked 12/1, 2011 at 12:13
2
Solved
I recently came across this really neat syntax, in the context of creating bash functions which can accept an argument or a stream from STDIN (i.e. can be piped to). On the surface, I understand wh...
Save asked 30/1, 2019 at 9:30
2
Solved
I am trying to append a path to the end of my PERL5LIB environment variable, but I am not sure that this variable will always exist. If it doesn't exist I would like to simply initialize it to the ...
Catholicism asked 8/12, 2017 at 21:55
2
Solved
Is there any way to use !$ in a parameter expansion context? The desired usage that motivates this question is rapid (in terms of key strokes) alteration of the name of a file (e.g., instead of sav...
Coastline asked 11/6, 2017 at 0:55
1
Solved
Problem
The behaviour of
!(pattern-list)
does not work the way I would expect when used in parameter expansion, specifically
${parameter/pattern/string}
Input
a="1 2 3 4 5 6 7 8 9 10"
...
Captious asked 29/5, 2017 at 12:3
2
I've googled and tried so many things and never could get anything to work with ${parameter@operator}. All I find is more links to the same documentation. So I think a proper answer with practical ...
Warranty asked 22/11, 2016 at 1:6
2
Solved
I'm trying to do a simple regex statement in a bash script that will match and substitute the end of a word. Below is what I'm trying to do.
wordh > word:’
Below is the code I'm using.
#!/bi...
Energetic asked 9/1, 2016 at 6:24
2
Inside of a while read line loop, I see this variable expansion ${line/device name:}. I've tried running the script with my own input file and it just prints out the line.
Can you tell me what th...
Thirsty asked 16/9, 2015 at 22:19
1
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