Redirecting command output to a variable in bash fails

Question

I\'m trying to redirect command output to a variable:

OUTPUT=$(sudo apache2ctl configtest)

and then to read it:

echo $OUTPU         


        

Answer 1

maybe the output goes to stderr, not stdout?

try this: OUTPUT=$(sudo apache2ctl configtest 2>&1)

Answer 2

For nginx possible situation when configtest can be successful with error in config files. Example:

nginx: [warn] conflicting server name "test.com" on 0.0.0.0:80, ignored
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

for correct check errors in bash scripts need use:

if [[ $((sudo /sbin/service nginx configtest) 2>&1 | grep "failed\|warn" ) ]]; then
    echo "ERROR!!!"
else
    echo "OK!!!"
fi