mjhjmtu

Let say, I am in a directory A, under A there are many folders (B, C, D, etc.), and in each folder there is a file "*.out" and sub-folders. I want to run a script from A which will look for the text "index123" in *.out file and print out all corresponding folder names.

Here is my sript:

#!/bin/sh 
FILES=home/A 
grep --include=*.out -rnw $FILES -e "index123" | while read file; do 
str1="FILES/$(basename $file)" 
echo $str1
done

This shows error.

N.B. This can be done by "find" in one line code, but why while loop shown shows error?

Assuming a directory structure like the following:

A
|-- B
| |-- file1.out
| |-- file2.out
| `-- file3.out
|-- C
| |-- file1.out
| |-- file2.out
| `-- file3.out
|-- D
| |-- file1.out
| |-- file2.out
| `-- file3.out
`-- E
 |-- file1.out
 |-- file2.out
 `-- file3.out

The issue with your code is that your grep will produce output that looks like

./B/file1.out:2:some data which includes the word index123
./B/file2.out:2:some data which includes the word index123
./B/file3.out:2:some data which includes the word index123
./C/file1.out:2:some data which includes the word index123
./C/file2.out:2:some data which includes the word index123
./C/file3.out:2:some data which includes the word index123
./D/file1.out:2:some data which includes the word index123
./D/file2.out:2:some data which includes the word index123
./D/file3.out:2:some data which includes the word index123
./E/file1.out:2:some data which includes the word index123
./E/file2.out:2:some data which includes the word index123
./E/file3.out:2:some data which includes the word index123

That is the output of

grep --include=*.out -rnw . -e "index123"

with A as the current directory.

You will then try to run basename on these individual lines, which fails since basename takes at most two arguments (a pathame and a suffix to strip from that pathname). GNU basename will complain about an "extra operand" while BSD basename will complain about incorrect usage.

grep will show you the names of the files (only, i.e. not the complete line that matched) when you use it with the -l flag.

This means that your script may be replaced by the single command

grep -w -l "index123" */*.out

This will give output on the form

B/file1.out
B/file2.out
B/file3.out
C/file1.out
C/file2.out
C/file3.out
D/file1.out
D/file2.out
D/file3.out
E/file1.out
E/file2.out
E/file3.out

I added -w as you used in your grep command line. -n (for numbering lines, which you are also using) may not be used together with -l.

Judging from your code, this is what you want.

If you need just the folder names, then do

$ grep -w -l "index123" */*.out | sed 's#/[^/]*##' | sort -u
B
C
D
E

All of this assumes that A is the current working directory, but you said that this was the case in the question so it shouldn't be a problem.

As per from the post find a file through particular search in while loop one of solutions can be as follow by using the while loop:

#!/bin/bash

while IFS= read -r d;

grep -q "index123" "$d" && dirname "$d"|awk -F'/' 'print $2'

done < <(find . -maxdepth 2 -type f -name "*.out")