logfiles - Regex to extract content from each line of a log file output from '_m' to the end of the line -

format of log line:

xxx x xx:xx:xx xmmxxx xxxxxx: xxxxxxx:xxx: xxx_mxxx_xxxxxx_mxxxxxmmxx [xxx xxxx. 

i want extract '_m' end of line, removing '_' before 'm'.

new regex...

thanks!

if tool/language support look-behind, works: match first _m till eol. ignore leading _

(?<=_)m.* 

test grep:

kent$  echo "xxx x xx:xx:xx xmmxxx xxxxxx: xxxxxxx:xxx: xxx_mxxx_xxxxxx_mxxxxxmmxx [xxx xxxx."|grep -po '(?<=_)m.*'  mxxxxxmmxx [xxx xxxx.