Linked Questions
2
votes
1
answer
6k
views
How to use negation of a command in a while loop with grep in shell script?
Is there any way to use while loop and grep all together?
See my example:
while [[ !(grep -R -h "${text}" ${path}) ]];
do
...
done
It says:
./test_script.sh: line 1: conditional binary ...
- 145
1
vote
2
answers
3k
views
When to quote a parameter expansion, and enclose parameter name in braces? [duplicate]
In a parameter expansion:
Is it always better (or not worse) to double quote a parameter expansion than not? Are there cases where double quoting is not suggested?
When is it necessary to add braces ...
- 94.9k
1
vote
4
answers
2k
views
Rename file using grep and for
I would like to rename files with following extensions: .txt, .data, .conf to ".xml"
hello.txt -> hello.xml
To do so, file must also contain the following line: <?xml version="1.0" encoding="UTF-...
- 61
2
votes
2
answers
2k
views
Bash: Globbing and file conditions [duplicate]
I am trying to check wether a file exists or not:
This works as expected:
if [ -e "/tmp/test.*.lock" ]; then
echo "exists!"
fi
This does not:
if [[ -e /tmp/test.*.lock ]]; then
echo "exists!"
...
- 68
2
votes
2
answers
361
views
Why is it not required to double quote `$bar` in assignment `foo=$bar`? [duplicate]
From https://unix.stackexchange.com/a/32227/674
The main places where it's safe not to use the double quotes are:
in an assignment: foo=$bar (but note that you do need the double quotes in ...
- 94.9k
2
votes
1
answer
747
views
Conditional emoji on terminal success and failure
I am using a Mac and I want to be able to show emoji X for every successful command that I type in and emoji Y for every command that results in failure.
- 131
1
vote
2
answers
3k
views
downloading a file behind a link
I want to write a script to download the WEbStorm IDE from Jetbrains and then do further stuffs. But I am unable to download the tar ball.
I am following this, but it doesnt solve my problem.
...
- 879
3
votes
1
answer
431
views
how to add a custom option to the mkdir command
I have created lots of directories and I would to make my life lazy and to auto cd into the directory that I made with the option of -g with the result of mkdir -g foo
The terminal would be like this:...
- 75
0
votes
2
answers
2k
views
How to ssh to a remote host using from within a bash script function? [duplicate]
I'm new to bash scripting. I want to call a function from my script which will ssh into a remote computer (on my LAN) and run a command.
So far I have:
function run_ssh_command {
target_ip=$1
...
- 533
2
votes
1
answer
705
views
If condition works for first time but not for the second time
I have defined the below for and if condition in a function. For the first time it runs well. Second time it doesn't gets executed after the for loop, it just writes the echo statement. Why does it ...
- 21
1
vote
4
answers
567
views
How to use as argument the characters + , - , x , / in a script [duplicate]
I am trying to write a script I will call calc.sh that does basic calculations using the arguments for the script ( $1, $2 and $3). For instance I'd like to get 2 as result for
./calc.sh 10 / 5
My ...
- 13
1
vote
1
answer
939
views
Populate array with a sed/echo combination
I'm trying to rename multiple files containing dates. I want to split the date into year, month and day and then create a new filename in a directory tree like year/month-year/filename_yearmonthday....
- 29
0
votes
1
answer
555
views
how to nest conditional script operators -a -o in an if statement in bash
If i want to combine the -a and -o script operators in an if statement, how could I do that? For example:
if [ ( -e file.txt -a -r file.txt ) -o ( -e file2.txt -a -r file2.txt ) ]; then .... fi
Can I ...
- 11
-1
votes
2
answers
83
views
if condition throws error
In bash coding, line3 is a path taken from xyz/symlinks_paths.txt.
while read -r line3
do
if [[ $(ls -lh $line3 | grep zzz.exe | grep '[8-9][0-9][0-9][MG]') -ne 0 ]]
then
echo $...
- 3
-2
votes
2
answers
132
views
How to use globs in flow control?
I have a list of directories (or folders if you will).
In each directory is a file called <something>.txt that is generated from a database dump.
I want to run a cron job that goes through and ...
- 237