All Questions
13
questions
0
votes
2
answers
232
views
How to expand variable within a single-quoted argument?
I am trying to perform the following without luck:
SORT_BY='-k3,3r -k2,2 -k1,1r'
awk 'NR<4{print $0;next}{print $0 | sort '"${SORT_BY}"' -t"~"}'
I have tried with all sorts of quotes, unquote, ...
- 285
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
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
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 $a
/root/fcm/~
>...
- 447
1
vote
1
answer
8k
views
Passing a variable argument to egrep in a bash script
I have a script, myScript, which is trying to egrep the script argument in a file. Somehow variable expansion isn't working properly with the egrep command. I believe I've isolated the problem ...
- 453
0
votes
1
answer
3k
views
Searching path as search pattern in grep command
I have saved the path in the variable .
var="/home/myfolder/subfolder"
Need to search whether the path in available in a text file using grep.
grep -l '${var}' * >abc.txt
I'm trying to list ...
- 197
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
2
votes
2
answers
211
views
variable substitution in CLI and for loops
I am pretty sure this has been asked already in some form, I just cannot come up with a good find to search it.
I want to have a script that do things N times and to which I can pass as a variable ...
- 319
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
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
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
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