UNIX for Advanced & Expert Users

It isn't clear to me whether tinku91 wants one expression that will match all six words or three different patterns each matching two words. But the following script should give you what you want:

Code:

echo 'i, ii, and iii'
grep -E '(harris|SIG(STOP|TSIP|TTIN|TTOU))' reg_exp

echo 'i'
grep -E 'SIG(STOP|TSIP)' reg_exp

echo 'ii'
grep -E 'SIG(TTIN|TTOU)' reg_exp

echo 'iii'
grep -E 'harris' reg_exp

I suspect that SIGTSIP is a typo and that what is really wanted is SIGTSTP, but this script looks for what was requested. Note also that any line that contains harrison also contains harris so there is no need to check for both harris and harrison.

Note to bipinajith:

Code:

grep  "^[SIG]\{3\}\(STOP\|TSIP\)" reg_exp

is not portable; many systems don't allow backslash escaped ERE syntax in BREs. The request didn't say anything about only matching at the start of a line. And, [SIG]{3} in an ERE will match GGG, III, SSS, GGi, GGS, etc. in additional to SIG.

Don, I understood. That repetition operator {3} was a mistake. Thank you for pointing that out.