Find exact word in file using egrep in bash

Question

I have a file called F1. F1 contains

Hello abc@
aaa ddd

Now, I want to check the word abc is in file F1.

After running the following command

find $dir -type f -exec egrep -w "abc" {} \;

This is the output I get

Hello abc@

For some reason the word abc@ was also found. (I was looking for abc.)

duplicate: http://stackoverflow.com/questions/4709912/how-to-grep-the-exact-match — Amir Afghani, Dec 25 '13 at 23:18

score 4 · Answer 1 · answered Dec 25 '13 at 23:40

4

This should do it:

egrep '(^| )abc( |$)' F1

It looks for abc surrounded by either space or line beginning/ending.

answered Dec 25 '13 at 23:40

Barmar

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score 2 · Answer 2 · edited Dec 25 '13 at 23:36

2

You're likely using GNU egrep - the -w option isn't part of the POSIX standard - and its manual page states

-w, --word-regexp
      Select  only  those  lines  containing  matches  that form whole
      words.  The test is that the matching substring must  either  be
      at  the  beginning  of  the  line,  or  preceded  by  a non-word
      constituent character.  Similarly, it must be either at the  end
      of  the  line  or  followed by a non-word constituent character.
      Word-constituent  characters  are  letters,  digits,   and   the
      underscore.

So @ is considered a non-word constituent character, just like , and . and whitespace.

If you have an idea of what you'd like the word separators to be, let us know and we can craft a regexp for you.

edited Dec 25 '13 at 23:36

Zombo

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answered Dec 25 '13 at 23:30

Mark Plotnick

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You absolutely right. I know that '@' is a non-word. Space is the word separator. – David Lesner Dec 25 '13 at 23:35
So it's telling you that there's a match because there is one. You are looking for the word "abc". Since `@` is not considered part of a word, it sees `abc@` as the word "abc" that you're looking for - incdentally followed by a `@`, but that doesn't change anything. So what exactly would constitute a match for you? – Mark Reed Dec 25 '13 at 23:37
David, if your file had the strings `abc.`, `abc!`, `abc#`, `abc%`, `abc*`, `abc,`, `abc-`, and `abc?`, which of those would you want `egrep -w` to find and which would you want it to ignore? – Mark Plotnick Dec 25 '13 at 23:42
I don't know Mark. All I know is that I want to be able to find out by given two inputs: a filepath and a word, weather or not the word is in the given file. – David Lesner Dec 25 '13 at 23:43
this should work find $dir -type f -exec grep -v [[:punct:]] {} \; | grep abc – Tharanga Abeyseela Dec 25 '13 at 23:46

Tharanga Abeyseela · Answer 3 · 2013-12-25T23:53:40.277

0

find $dir -type f -exec grep -v [[:punct:]]  {} \; | grep -ow abc

edited Dec 25 '13 at 23:53

answered Dec 25 '13 at 23:22

Tharanga Abeyseela

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No, still find 'abc@'. – David Lesner Dec 25 '13 at 23:27
can't be i'm getting this [root@rhce sto]# find . -type f -exec egrep -o "abc" {} \; abc – Tharanga Abeyseela Dec 25 '13 at 23:28
The output I get is: 'abc'. But it shouldn't give any output. Cause Iam looking for a word that doesn't exists in F1. – David Lesner Dec 25 '13 at 23:30
sorry, according to your question, you were looking for the word "abc" only ? – Tharanga Abeyseela Dec 25 '13 at 23:33
I want to know weather or not the word 'abc' exists in file F1. – David Lesner Dec 25 '13 at 23:39
try this find $dir -type f -exec grep -v [[:punct:]] {} \; | grep abc – Tharanga Abeyseela Dec 25 '13 at 23:45
ok, i edited my answer above. so that will be helpful to anyone else. cheers – Tharanga Abeyseela Dec 25 '13 at 23:57

Find exact word in file using egrep in bash

3 Answers3