filesystems - awk part string compare -

i trying extract part of string using bash or awk.

i think can solve problem using read or awk.

my input_file below

cat ./input_file  in_size=1 # out_size=2 

so,

out_size=$(awk '{if($2=="out_size=2"){ blabla ; print output}' ./input_file) 

i don't know how solve problem.

and, how can set multiple field separator fs empty space , tab.

there example like

fs='[/=]' 

how can use 4 fs / = " " "\t" ??

thanks in advance.

use posix-style character class [:blank:] includes horizontal whitespace characters.

awk -f '=|[[:blank:]]+' '{     (i=1; i<nf; i++) {         if ($i == "out_size") {             print $(i+1)             exit         }     } }' filename 

unless know it's 2nd word:

awk -f '=|[[:blank:]]+' '$2 == "out_size" {print $3; exit}' filename