topic Re: grep and whole words in Operating System - Linux

grep and whole words

oiram — Mon, 23 Dec 2002 10:07:36 GMT

Hello:

imagine the next file
---------
/test
/test/hello
/testA
---------
I need to make a grep over it to obtain only the first entry(/test). If I use the -w option I get the following
/test
/test/hello

This must be easy but I don??t know how to do it.

Regards.

Re: grep and whole words

T G Manikandan — Mon, 23 Dec 2002 13:56:12 GMT

you can pipe it to head

like

/tmp/a

---------
/test
/test/hello
/testA
----------

cat /tmp/a|grep test |head -1

Re: grep and whole words

Alan Deger — Mon, 23 Dec 2002 16:21:36 GMT

With what you've shown here you can get the results you want with an end-of-line metacharacter. Your grep command would look like

grep "/test$" myfile

Hope this helps,
ard

Re: grep and whole words

Bob_Vance — Tue, 24 Dec 2002 14:37:46 GMT

If you really want to worry about "words" and assume that the word delimeter is white space (tab or blank), then a more complete expression would be:

grep -E '/test$|/test[[:space:]]' /tmp/x

This checks for the word "/test" at the end of line *or* followed by a whitespace char.

E.g., for the file:
# cat /tmp/x
/test
/test one blank
/test 2 blanks
/test tab
/test/hello
/testA

the results are:

# grep -E '/test[[:space:]]|/test$' /tmp/x
/test
/test one blank
/test 2 blanks
/test tab

bv