Parse string with bash and extract number

Question

I\'ve got supervisor\'s status output, looking like this.

frontend                         RUNNING    pid 16652, uptime 2:11:17
nginx                                


        

Answer 1

assuming that the grep implementation supports the -o option, you could use two greps:

output \
  | grep -o '^nginx[[:space:]]\+[[:upper:]]\+[[:space:]]\+pid [0-9]\+' \
  | grep -o '[0-9]\+$'