How to check if directories starting with a particular string exist or not?

Question

What command can be used to check if directories starting with a particular pattern exists or not, within shell script ?

For example :

In HOME path if there are many directories starting with ABCD_* and i want to check if there are any directories staring with pattern- ABCD_* exist or not using a command.

If (any directory matching this pattern exist) then echo found else echo not found fi

In `bash` you cannot return `true` or `false`. Do you mean the status codes `0` and `1` or do you want to print something? — Socowi, Mar 01 '21 at 09:44

Raman Sailopal · Answer 1 · 2021-03-01T09:53:04.577

1

find ~ -type d -name "ABCD_*"

Search the home directory of the current user (~) for directories (-type d) with the pattern "ABCD_*" (using -name)

You can then use this in an if condition by integrating it with wc -l and so:

if [[ "$(find ~ -type d -name "ABCD_*" | wc -l)"  -gt "0" ]];
then 
    echo "Found";
else
    echo "Not Found";
fi

edited Mar 01 '21 at 09:53

answered Mar 01 '21 at 09:32

Raman Sailopal

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Hi @Raman thanks for the answer. This will print the path and list of directories matching this condition. What i want is a boolean value whether it is present or not. – Atif Sheikh Mar 01 '21 at 09:38
@AtifSheikh you simply need to wrap the code you've been provided with in an if statement. – arco444 Mar 01 '21 at 09:41
Hi @arco44 i am already using this. I am using if condition and if found then it is printing path and then executing business logic. I dont want that. – Atif Sheikh Mar 01 '21 at 09:44
I've added an if condition – Raman Sailopal Mar 01 '21 at 09:53

Socowi · Answer 2 · 2021-03-01T10:02:27.633

Use a glob and count the number of matches. To ensure that only directories are matched, use a trailing /.

Counting can be done with arrays ...

shopt -s nullglob
found=(~/ABCD_*/)
if (( "${#found[@]}" > 0 )); then
  # there are directories starting with ABCD_
else
  # there are no such directories
fi

... or by a function ...

hasArgs() {
  (( $# > 0 ))
}
shopt -s nullglob
if hasArgs ~/ABCD_*/; then
  # there are directories starting with ABCD_
else
  # there are no such directories
fi

How to check if directories starting with a particular string exist or not?

2 Answers2