All Questions
Tagged with quoting variable-substitution
24
questions
26
votes
6
answers
125k
views
Is there any way to print value inside variable inside single quote?
Consider I've set variable site and needs to be printed by echo or printf, but If I use single quote to write something and want to use variable then how?
Example:
$ site=unix.stackexchange.com
$ ...
- 24.9k
19
votes
2
answers
95k
views
Passing a variable to sed [duplicate]
I cannot not use a shell variable in sed in the $NUMBER form. I have this line in my shell script:
cat shared.txt sed 's/whatever1/$2 ... whatever2/' > shared2.txt
The result in shared2.txt looks ...
- 375
9
votes
4
answers
7k
views
Can I reload variable in a watch command?
Part of my job involves some data handling. One of the tasks is to 'flatten' a set of directories (which we'll call Dir for now), and copy them to a new location called DirFlat.
This can take a long ...
- 1,794
8
votes
3
answers
3k
views
How does Bash handle quoting in the string replacement section of parameter expansion?
Is there any consistent logic to it?
some-command "${somevariable//some pattern/'how does this get parsed?'}"
I've posted some conclusions and raw tests below as an "answer" but they're not a full ...
- 36.8k
6
votes
4
answers
18k
views
Backslash in variable substitution in Bash
I was working on a Bash script to help partition a hard drive correctly, and I came across a strange problem where I had to append a number to a variable. It took me a while to get the outcome right ...
user270900
5
votes
3
answers
8k
views
Spaces for variables in bash script
I have a space in one of the directory names. I want to list a file under it from a bash script. Here is my script:
fpath="${HOME}/\"New Folder\"/foobar.txt"
echo "fpath=(${fpath})"
#fpath="${HOME}/$...
- 153
4
votes
1
answer
939
views
readlink literal vs variable
Using BASH: the answer is probably obvious but, not for me.
> echo $PWD
/root/fcm
> readlink -f ~
/root
> # but then with a variable or literal
> a='~'
> readlink -f $a
/root/fcm/~
>...
- 447
3
votes
1
answer
4k
views
Is `echo $TEST` expanding an asterisk in the variable a bug? [duplicate]
Is this a Bash bug?
$ mkdir test && cd test && echo "a" > "some.file"
test$ echo '*'
*
test$ TEST=$(echo '*')
test$ echo $TEST
some.file
Why is the second output the resolution of ...
- 250
3
votes
1
answer
7k
views
Grep pattern that has double quotes and variable substitution surrounded by single quotes
So, Let's say I have the following pattern:
Thisisatest="1"
in a file called file.
And I want to match the exact string above but for whatever reason, I choose to loop over some numbers ...
- 2,342
3
votes
3
answers
3k
views
Variable expansion in Bash
I tried the following commands
variable='one|name'
echo $variable
The output is
one|name
whereas echo one|name gives an error No command 'name' found. This is reasonable because bash treats | as a ...
- 461
3
votes
1
answer
3k
views
variable expansion within command substitution over SSH bash 4.X
I want to do this ssh ${w100user}@web100 'ls -l "$(grep "${1}" /etc/pure-ftpd/pureftpd.passwd|cut -d':' -f6)"'
Which obviously performs an ssh session to server web100 as w100user and then greps ...
- 7,660
3
votes
1
answer
1k
views
Double Quotes in Bash's variable substitution
I am trying to configure some software packages with a script thereby I got the following problem. Assume that the environment variable PREFIX is set to the location where I plan to install the ...
- 191
2
votes
2
answers
4k
views
Environment variable not expanded inside the command line argument
I have a file user-pid.out2 which has "usernumber" and "process id" as two columns. based on usernumber I want to find corresponding process id. the first two lines below does not show the output ...
- 21
2
votes
2
answers
369
views
What is the right way to quote nested parameter expansions?
When dealing with with nested parameter expansions, which of these is the correct way to quote things?
This one:
var="${var#"${var%%[![:space:]]*}"}"
Or this one:
var="${var#${var%%[![:space:]]*}}"...
- 1,964
2
votes
1
answer
5k
views
bash: export: `--wait': not a valid identifier
When I run git-sh from my terminal it works fine. But I get the following warning.
bash: export: `--wait': not a valid identifier
What is this and how do I get rid of it?
- 141