while using '$?' expression in bash script

Question

I'm writing a simple bash script

#!/bin/bash

ls xyzzy.345 > /dev/null 2>&1
status =' echo $?'
echo "status is $status"

which finds the file xyzzy.345 and logs the result to /dev/null. But when it comes to the line status =' echo $?', I get this error:

status: Unknown job: = echo $?

But echo $? is recognized in the terminal.

Can anybody help me? My OS is ubuntu 12.04 LTS

Have you tried the || and && syntax to check if the command was ok or failed? Have you tried a if to check if the file exists instead of checking the return value from ls? — Johan, Sep 11 '14 at 11:30

Stéphane Chazelas · Answer 1 · 2014-09-11 11:23:38Z

You have an extra space between status and the =. Bash variable assignments need to have no space between the name and the = sign:

status='echo $?'

What you've written is calling the status command with the single argument =' echo $?'.

All of that said, I think that what you probably want to write is:

status=$?

That stores the value of $? into the status variable.

If your real code is a little more complicated and you want to run a command and save the value, use either of these:

status=`echo "$?"`
status=$(echo "$?")

These use command substitution to access the output of a command.

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