How to match with a string containing litteral dot "." with grep command ?

coolloo_djack · 03-17-2010, 12:07 PM

Hiya!

I want to find out into some directory, all the files which names are composed of : A specific word README, a litteral "." and any string

file name sample like: "README.string"

thank you!

smoker · 03-17-2010, 12:16 PM

Don't use grep use ls
ls -l README.*
or find
find README.* /

will search the whole computer.
find README.* /home will only search home directories

or
ls -Rl | grep README.

will search from the current directory down through all subdirectories.

Or of course
find /home -name "README.*" will search home

primerib · 03-17-2010, 12:20 PM

It needs to be backslashed.

grep "." matches any char, grep "\." matches "." the period.

edit: sorry, misread your post. Do as Smoker suggested.

colucix · 03-17-2010, 12:27 PM

Indeed, since . (dot) in a regular expression means any single character, you have to escape it using \ (backslash) or enclose it in a character list (square brackets) and use extended regexp (option -E)

Code:

$ ls | grep -E 'README\..+'
$ ls | grep -E 'README[.].+'

Anyway to just list certain filenames, you can use ls and the globbing capability of the shell:

Code:

$ ls README.*

this will be expanded to the filenames beginning with "README." and optionally followed by any suffix. In this case the dot is interpreted literally, since ls does not accept regular expressions as argument.
Finally, if you want to find files recursively in all sub-directories you can try the find command, as in:

Code:

$ find . -name 'README.*'
$ find . -regex '.*README\..+'

gnashley · 03-17-2010, 01:15 PM

Even better: 'echo *.*', since ls/find won't return names with spaces correctly.

ghostdog74 · 03-17-2010, 10:07 PM

bash 4

Code:

shopt -s globstar
for file in /path/**/*README.*
do
  echo $file
done