I have to find some lines in a file which contain a particular character twice.

for example,

if the repeating character is ':' and the file is like...

abc:fgh
afg:rfg jhk:ret <-- this line is needed.
mmv:wre

how can i do this?

Hello, how are you doing? I believe that I have the answer to your question, provided that there is a space separation between the two entities containing the colons (. If this IS the case, then the following command can be used:

pg FILE_NAME | grep : | grep ' '

This will then display any line containing the colon and that also has a space and another colon. Hence, for your example, only the second line will be displayed.

In the meantime, I will be thinking of a more slick way to search for such lines. Take care.

JHeliosfear

for the particular requirement.. it works fine. but when i go for something more.. it fails. can i have an exact remedy for the problem?

Try:
grep '\:[^:]*\:' filename

thanks,
that works good.