Hi,
I'm trying to egreg for a couple strings whcih are (0) and SYSTEM. The problem is the syntax for egreg is:
egreg "(string1|string2)"
With my basic knowledge of UNIX I don't know how to include '(0)' within "(string1|string2)" apart from trying to use single quotes which doesn't work, i.e. "('(0)')".
I reckon this must be eary to resolve but need some expert advice.
Can anyone help?
Gareth
why dont u try as such,
egrep '(0)|system' filename
Thanks, I've tried this and it doesn't work. This provides the same output as:
egrep -v "0|SYSTEM"
i dont understand,
can u plz post the sample input and output.
Madhan's command works absolutly fine.. here is how it works
$ more tmp1
hai it is the begining
this is test (0) for unix.com
also to test SYSTEM for the same
this is the end of the file
$ egrep '(0)|SYSTEM' tmp1
this is test (0) for unix.com
also to test SYSTEM for the same
can you tell me what was the error you got ?
I don't know if egrep works the same everywhere, but: why not use grep instead?
grep -e "0" -e "SYSTEM"
will find every line containing either "0" or "SYSTEM" - at least on my AIX system.
bakunin
Whilst you're seeing what you think is the correct output that's because it's actually greping for 0 and SYSTEM
# cat tmp
hai it is the begining
this is test (0) for unix.com
also to test SYSTEM for the same
this is the end of the file
this is test 0 for unix.com
If I want to exclude lines including (0) using your syntax I get the following result:
# egrep -v '(0)|SYSTEM' tmp
hai it is the begining
this is the end of the file
Line 5 should not have been removed if the pattern is (0)
You have to escape the '(' and the ')'. Like this:
$ cat test
hai it is the begining
this is test (0) for unix.com
also to test SYSTEM for the same
this is the end of the file
this is test 0 for unix.com
$ egrep -v '\(0\)|SYSTEM' test
hai it is the begining
this is the end of the file
this is test 0 for unix.com
Here is some food for thought. I wanted to do this without the quotes, so I fiddled around and got this:
How are
egrep -v '\(0\)|SYSTEM' test
and
egrep -v \\\(0\\\)\|SYSTEM test
the same?
Ran the two on FreeBSD 4.6 under ksh. Check the output:
$ cat test
hai it is the begining
this is test (0) for unix.com
also to test SYSTEM for the same
this is the end of the file
this is test 0 for unix.com
$ egrep -v '\(0\)|SYSTEM' test
hai it is the begining
this is the end of the file
this is test 0 for unix.com
$ egrep -v \\\(0\\\)\|SYSTEM test
hai it is the begining
this is the end of the file
this is test 0 for unix.com
I dont need the explaination about having to escape the '|'. Its the multiple \s.
Thanks, that's sorted it, I new it'd be summat simple just didn't know how to escape the brackets.
Many thanks for everyone's help