I'm trying to redirect command output to a variable:
OUTPUT=$(sudo apache2ctl configtest)
and then to read it:
echo $OUTPUT
When running it the output is the following:
19:19:12 user@user ~ OUTPUT=$(sudo apache2ctl configtest)
Syntax OK
Syntax OK
But the variable stays blank. I've tried the same for other commands and everything works fine.
OUTPUT=$(ls -l)
This writes file list to variable OUTPUT so that it can be read later.
What should i do to make it work?
Maybe the output goes to stderr, not stdout? Try this:
OUTPUT="$(sudo apache2ctl configtest 2>&1)"
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
if [[ $(<cmd>) ]]; then; echo error; else echo ok; fi cound be written as <cmd> || { echo error; } && { echo ok; }, which is a bit less verbose and gives the command a bit more prominence. (The curly braces (along with the semicolons) in my example could be left out as well if they only contain one command and the whole thing is a one-liner.)