How to grep for the exact word if the string has g

问题:

I was trying to search for a particular word BML.I in a current directory.

When I tried with the below command:

grep -l  "BML.I" *

It is displaying all the results if it contains the word BML

Is it possible to grep for the exact match BML.I

回答1:

You need to escape the . (period) since by default it matches against any character, and specify -w to match a specific word e.g.

grep -w -l "BML\.I" *

Note there are two levels of escaping in the above. The quotes ensure that the shell passes BML\.I to grep. The \ then escapes the period for grep. If you omit the quotes, then the shell interprets the \ as an escape for the period (and would simply pass the unescaped period to grep)

回答2:

try grep -wF

from man page:

 -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.



 -F, --fixed-strings
              Interpret  PATTERN as a list of fixed strings, separated by newlines, any
              of which is to be matched.  (-F is specified by POSIX.)

回答3:

I use fgrep, which is the same as grep -F

回答4:

Use this command:

ls | grep -x "BML.I"