All Questions
9 questions
0
votes
1
answer
537
views
bash: string variable contains asterisk. how to use this variable for searching etc with grep, sed?
Have a nice day
I have got text file (zz.txt):
Chemical name
3-Aminopropane-1-sulphonic acid
Synonym(s)
--
Homotaurine * Tramiprosate
--
Chemical name
Common name and synonyms
...
I have variable
s=&...
- 3
2
votes
1
answer
1k
views
Why does variable expansion in commands not work in ZSH but it does in BASH?
I have set an environment variable and want to use it when calling a command, but no dice.
The full command, without variable, works:
nacho@WouldntYouLikeToKnow ~ % ls -la ~/Downloads
...
- 433
0
votes
1
answer
2k
views
How to save a result of any command into a variable?
Let's take this command
sudo doveadm pw -s SHA512-CRYPT -p '$$!!!555;###..>^$$'
How can redirect its output into a variable?
- 1
7
votes
2
answers
3k
views
How to source some shell code not a file?
There is a description of a source command:
source is a bash shell built-in command that executes the content of the file passed as argument, in the current shell. It has a synonym in . (period).
For ...
- 323
37
votes
3
answers
6k
views
Why is opening a file faster than reading variable content?
In a bash script I need various values from /proc/ files. Until now I have dozens of lines grepping the files directly like that:
grep -oP '^MemFree: *\K[0-9]+' /proc/meminfo
In an effort to make ...
- 1,715
61
votes
3
answers
15k
views
How can I expand a quoted variable to nothing if it's empty?
Say I have a script doing:
some-command "$var1" "$var2" ...
And, in the event that var1 is empty, I'd rather that it be replaced with nothing instead of the empty string, so that the command executed ...
- 76.3k
17
votes
3
answers
10k
views
Loop over a string in zsh and Bash
I would like to convert this Bash loop:
x="one two three"
for i in ${x}
do
echo ${i}
done
in such a way to work with both Bash and zsh
This solution works:
x=( one two three )
for i in ${x[@]...
- 1,513
0
votes
1
answer
55
views
Is there a valid way of exporting a variable across different shells?
For some reasons, Im using ksh and zsh in my scripts and returning to -bash, I need to use already set variable values in the spawned shells, writing it to some temp file and using that didn't look ...
- 1,359
12
votes
6
answers
8k
views
Serialize shell variable in bash or zsh
Is there any way to serialize a shell variable? Suppose I have a variable $VAR, and I want to be able to save it to a file or whatever, and then read it back later to get the same value back?
Is ...
- 223