[linux] Shell script : How to cut part of a string

I have following string

â   â³ eGalax Inc. USB TouchController          id=9    [slave  pointer  (2)]
â   â³ eGalax Inc. USB TouchController          id=10   [slave  pointer  (2)]

and would like to get the list of id ? How this can be done using sed or something else ?

$ ruby -ne 'puts $_.scan(/id=(\d+)/)' file
9
10

You can have awk do it all without using cut:

awk '{print substr($7,index($7,"=")+1)}' inputfile

You could use split() instead of substr(index()).

Assuming input of

{Anything}id={ID}{space}{Anything} 
{Anything}id={ID}{space}{Anything}

--

#! /bin/sh
while read s; do
   rhs=${s##*id=}
   id=${rhs%% *}
   echo $id # Do what you will with $id here
done <so.txt 

Or if it's always the 7th field

#! /bin/sh
while read f1 f2 f3 f4 f5 f6 f7 rest
do
echo ${f7##id=}
done <so.txt

See Also

Shell Parameter Expansion

A perl-solution:

perl -nE 'say $1 if /id=(\d+)/' filename

Use a regular expression to catch the id number and replace the whole line with the number. Something like this should do it (match everything up to "id=", then match any number of digits, then match the rest of the line):

sed -e 's/.*id=\([0-9]\+\).*/\1/g'

Do this for every line and you get the list of ids.