All Questions
18 questions
2
votes
1
answer
841
views
issues with $ symbol while reading from positional parameters in unix shellscript
I have written the following script:
#!/bin/bash
TEST=$1
TEST_1=$2
if [[ "$TEST" == e ]];then
echo $TEST_1
else
echo "Input is not e"
fi
Now if I will run:
sh test.sh e NS3#$xX$...
- 73
6
votes
3
answers
11k
views
How to prevent parameter expansion around a variable I want to be resolved?
Edit:
Important note before reading further: since Kusalananda's anwser, my question is now quite useless, since he pointed out a bug in another script I used. Now this bug is fixed, the below errors ...
- 362
1
vote
2
answers
2k
views
Shell Script: how to expand a variable into quotes
Can anyone tell me how can I make the follow command to work properly?
SERVER=192.168.1.1
ping $SERVER (It Works)
ping '$SERVER' (It doesn't work)
I want this to compose a more complex command that ...
- 135
21
votes
2
answers
13k
views
How Can I Expand A Tilde ~ As Part Of A Variable?
When I open up a bash prompt and type:
$ set -o xtrace
$ x='~/someDirectory'
+ x='~/someDirectory'
$ echo $x
+ echo '~/someDirectory'
~/someDirectory
I was hoping that the 5th line above would have ...
- 312
0
votes
1
answer
641
views
Do I need to double quote a variable?
I am confused on when we double quote shell variables.
Specifically I am using the following sed replace command:
sed -i.tmp "/$MY_VAR/d" /foo/bar/file.txt
But I am not quoting $MY_VAR. Is this ...
- 10.5k
1
vote
1
answer
4k
views
Basic syntax explanation for variables in bashrc
I want to correctly export a variable. In order to do so I have to understand several variations in syntax. I've seen the following mechanisms of exporting a variable. In this case I am using ....
- 1,971
0
votes
1
answer
2k
views
Print a variable in single quote on bash | Weird Variables
On bash script, I need to pass date as ansible extra variable but getting something single quotes related issues;
...
$DT="03-04-17"
ansible-playbook copy2s3.yml --extra-vars 'cdate={{ "$DT" }}'
and ...
- 603
2
votes
2
answers
144
views
shell command 'var="[a-p]"; echo $var' has as output "h", any explanation? [duplicate]
bash version:
$ bash -version
GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu)
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu....
- 123
3
votes
3
answers
218
views
What situations exist where Bash variables should not be double quoted? [duplicate]
I'm aware of several situations where it's unnecessary to use double quotes when expanding a variable in Bash, such as inside [[...]], or when used on the right hand side of a variable assignment.
...
- 280
20
votes
6
answers
1k
views
Should variables be quoted when executed?
The general rule in shell scripting is that variables should always be quoted unless there is a compelling reason not to. For more details than you probably want to know, have a look at this great Q&...
- 250k
1
vote
1
answer
6k
views
Script with variable in path
I'm not entirely sure where to ask or how to formulate this question with correct terminology.
I have script here for managing a game (minecraft) server for the user (bukkit).
I've cut out some ...
- 13
2
votes
1
answer
2k
views
Inserting variables in a command within a shell script
I'm attempting to write an automated script which will update the IP address for my Raspberry Pi within my /etc/hosts file.
I'm able to execute this line just fine,
IP=`sudo nmap -sP 10.61.4.0/24 | ...
- 133
1
vote
2
answers
2k
views
A variable in Bash that contains quotation marks and spaces
I'm trying the following in a Bash script:
MV_PARAMS='"foo 1" "foo 2"'
mv $MV_PARAMS
What I want to actually execute is:
mv "foo 1" "foo 2"
But it doesn't seem to work. trying this:
mv "$MV_PARAMS"
...
- 123
4
votes
1
answer
155
views
"$@" expansion for user defined variables
I'm trying to get a (bourne shell) variable to expand like "$@" so it produces multiple words with some having preserved spaces. I've tried defining the variable in many different ways but still can't ...
- 43
2
votes
3
answers
4k
views
Variable expansion inside parentheses and quotes
In the script below, I can't seem to make $var1 expand in the second statement. I've tried $var1, ${var1}, echo $var1 and '$var1'. It is inside a few sets of quotes and parentheses which I guess is ...
- 123