combine output of pipes-CodePudding

Let's say I run a command in Bash like:

ls  -l | grep filename

How can I save output of both command to a variable? In another words output of "ls -l" and "grep filename" to the same variable? The command must use a pipe.

Thank you in advance!

combinedOutput = ""

ls -l
total 4
-rw-r--r-- 1 webmaster webmaster 0 Nov 16 20:34 a
-rw-r--r-- 1 webmaster webmaster 0 Nov 16 20:34 b
-rw-r--r-- 1 webmaster webmaster 0 Nov 16 20:34 file1.txt
-rw-r--r-- 1 webmaster webmaster 0 Nov 16 20:34 file2.txt
-rw-r--r-- 1 webmaster webmaster 5 Nov 16 20:34 main.sh

ls  -l | grep main.sh
-rw-r--r-- 1 webmaster webmaster 20 Nov 16 20:35 main.sh


echo  $combinedOutput 
total 4
-rw-r--r-- 1 webmaster webmaster 0 Nov 16 20:34 a
-rw-r--r-- 1 webmaster webmaster 0 Nov 16 20:34 b
-rw-r--r-- 1 webmaster webmaster 0 Nov 16 20:34 file1.txt
-rw-r--r-- 1 webmaster webmaster 0 Nov 16 20:34 file2.txt
-rw-r--r-- 1 webmaster webmaster 5 Nov 16 20:34 main.sh
-rw-r--r-- 1 webmaster webmaster 20 Nov 16 20:35 main.sh

UPDATE #1: A better example: let's say I am trying to archive and compress a directory using the following command:

tar  cvf - /some/directory/ |  pigz --verbose -1 -p 4 >compressed_archive.tgz;

The question is how to put outputs of "tar cvf - /some/directory/" and "pigz --verbose -1 -p 4 >compressed_archive.tgz" to a variable.

CodePudding user response：

Just run two commands.

combinedOutput=$(
   ls -l
   ls -l | grep filename
)

But anyway, you may be more comfortable with just:

one=$(ls -l)
two=$(ls -l | grep filename)
combinedOutput="$one
$two"

It's not possible to get the output you want with echo $combinedOutput. You can do echo "$combinedOutput". Consider researching shell quoting. Check your scripts with shellcheck.

CodePudding user response：

Simply:

combinedOutput=$(( ls -l | tee /dev/stderr | grep filename ) 2>&1)
echo "$combinedOutput"