Question

I tried below command to store output to variable :

k=$(kill -HUP 1234)  #command getting executed but not storing to variable
echo "$k"

For checking if the output contains the word, i can do like this :

  if [[ outputvar =~ .*No such process*. ]]

As per the examples, above should work , but i donno why its not working . Can you tell me correct way so that if I cannot restart the process, I can atleast start a new process with direct gunicorn_django command

Answer 1

Usually such error messages are output on the stderr stream, while the $() construct returns only the stdout stream. You need to redirect stderr to stdout:

k=$(kill -HUP 1234 2>&1)

Your regular expression has an error: the *. at the end must be .*; you will also need to quote your strings in your test:

if [[ "$k" =~ .*No\ such\ process.* ]]

Note that "$k" is quoted, while the spaces in the regular expression are escaped; you cannot quote the regular expression (as ".*No such process.*"), as using a quoted string in a =~ test forces string match instead of a regular expression match.