bash - Find a port in a configuration file with regex -

in configuration file (nginx default.conf) got strings this:

server {         listen   80;         server_name sudomain1.somewhere.com ;         location / {                 proxy_set_header host sudomain1.somewhere.com;                 proxy_pass         http://127.0.0.1:8999/;                 } } 

in bash script, catch port number "8999" in variable use after in script.

if possible using entire string above.

because in file have several times sequence, , variable mark "subdomain1"

does know how this?

you can single line:

( ln=$(grep -a 1 sudomain1 nginxconf.txt | tail -n1); port=${ln##*:}; port=${port%/*}; echo "port: $port" ) 

or script:

#!/bin/bash  ln=$(grep -a 1 sudomain1 nginxconf.txt | tail -n1)  port=${ln##*:} port=${port%/*}  echo "port: $port" 

you first locate sudomain1 , line follows using grep -a 1 use tail -n keep last line. simple parameter matching/substring extraction isolate 8999.

output

port: 8999 

note: spell subdomain1 sudomain1 in conf file.