I want to save all filenames that matches the pattern in bash array.
My solution does not work. I think the problem is because of pipe usage, but I don't know how to fix it.
i=0 find . -type f | grep -oP "some pattern" | while read -r line; do arr[$i]=$line; let i=i+1; done With bash-4.4 and above, you'd use:
readarray -d '' -t arr < <( find . -type f -print0 | grep -zP 'some pattern') With older bash versions:
arr=() while IFS= read -rd '' file; do arr+=("$file") done < <(find . -type f -print0 | grep -zP 'some pattern') Or (to be compatible to even older versions of bash that didn't have the zsh-style arr+=() syntax):
arr=() i=0 while IFS= read -rd '' file; do arr[i++]=$line done < <(find . -type f | grep -zP 'some pattern') Your approach has several problems:
-o, grep only prints the parts of the records that match the pattern as opposed to the full record. You don't want it here.find's default newline-delimited output can't be post processed as the newline character is as valid as any in a file path. You need a NUL-delimited output (so -print0 in find and -z in grep to process NUL-delimited records.IFS= to read.bash, and without the lastpipe option, the last part of a pipe line runs in a subshell, so there, you'd only be updating the $arr of that subshell.