Command substitution is the replacement of a command with the result returned after it is evaluated.
Questions tagged [command-substitution]
234 questions
-1
votes
2 answers
Bash function with parameters
I am trying to understand how to work with functions (that receive a argument) in bash. I did not get my code to work, the following code exemplifies my difficulties:
#!/bin/bash
fruit_code () {
if [[ "$1" == "apple" ]]; then
…
Miguel Garcia
- 97
- 1
- 8
-1
votes
1 answer
bash command substitution executed as a single command not parsed as shell statement
It seems command subsitution take the first token as the command, remainings as the arguments of command,
not parsed as shell statement. but the bash manual says that :
Bash performs the expansion by executing command in a…
yuanjianpeng
- 335
- 1
- 9
-1
votes
1 answer
Issue in executing docker command in bash script
I have following bash script code try to run a docker container through bash script but I am retreiving error.
#!/bin/bash
name=sudo docker ps | grep 'test' | awk '{print
$1}'
sudo docker exec -it $name bash
error:
docker exec requires at least…
ash luck
- 17
- 5
-1
votes
1 answer
Is there a way to display function output in bash command
Have a simple bash script I am working on with Mac, but I am having one issue.
#!/bin/bash
# Pull users IP from getifaddr on specfic port
myip ( ) {
#ipconfig getifaddr ppp0
local _ip _myip _line _nl=$'\n'
while IFS=$': \t' read -a…
ChanSantheMan
- 3
- 2
-1
votes
2 answers
awk command fails with command substitution
Running this command fails:
$(printf "awk '{%sprint}'" $(tail -n +2 file.txt | cut -f2 | sort | uniq | awk 'BEGIN{a=1}{printf "gsub(\"%s\",%i);", $1,a++}')) file.txt
It gives the following error:
awk: '
awk: ^ invalid char ''' in…
BFH
- 99
- 7
-1
votes
1 answer
Bash assignment value to variable as command substitution and print value output
I would like to achieve this in Bash: echo $(a=1)and print the value of variable a
I test eval, $$a,{}, $() but none of them work as most of the times either I got literally a=1 or in one case (I don't remember which) it tried to execute the…
Alex
- 39
- 1
- 1
- 5
-1
votes
1 answer
How can I call a Bash function without invoking command substitution?
I have a Bash function that has a Perl-style "or die". For example,
#!/bin/bash
func1 () {
local val
val=`cat foobar` || exit 7
echo "func1: cat returns $?"
}
myval=`func1`
echo "Line X should not be reached (retn = $? val =…
KlaxSmashing
- 335
- 3
- 12
-2
votes
1 answer
seq command unkown service or name
#!/bin/bash
for ip in 'seq 1 254'; do
ping -c 1 $0.$ip | grep "64 bytes" | cut -d " " -f 4 | tr -d ":" &
done
the file is ipsweep.sh
when i run it show me this
root@kali:ping: ./ipsweep.sh.seq: Name or service unkown
R3d_F1lc0n
- 21
- 4
-3
votes
2 answers
Passing multi-line command output to echo outputs only a single line
I have 2 files in my folder as shown below
$ ls -l
total 1
-rw-r--r-- 1 user user-group 0 May 10 14:49 test
-rw-r--r-- 1 user user-group 0 May 10 14:49 test1
Listing the files is showing normal. But why does below command shows both the lines…
Deepak Janyavula
- 348
- 4
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