Grep – How to Grep Word Within a File and Copy the File

cpfindgreptext processing

I have a collection of files ( *.zip, *.txt, *.tar.gz, *.doc, …etc ). These files reside within a path. I want to find all the files ( *.txt), then copy, only, the text files that contain specific words ( e.g LINUX/UNIX).

I ran the following:

find . -name "*.txt" | grep 'LINUX/UNIX'

This command was able to find all the text files, then "grep" filtered the resultant text files by listing only the text files that contain 'LINUX/UNIX'.

How can I copy these final files (i.e. the text files that contain 'LINUX/UNIX') to a specific path of choice?

I tried to apply xargs

find . -name "*.txt" | grep 'LINUX/UNIX' | xargs cp <to a path>

But it didn't work

Best Answer

Try:

grep -rl --null --include '*.txt' LINUX/UNIX . | xargs -0r cp -t /path/to/dest

Because this command uses NUL-separation, it is safe for all file names including those with difficult names that include blanks, tabs, or even newlines.

The above requires GNU cp. For MacOS/FreeBSD, try:

grep -rl --null --include '*.txt' LINUX/UNIX . | xargs -0 sh -c 'cp "$@" /path/to/dest' sh

How it works:

grep options and arguments
- -r tells grep to search recursively through the directory structure. (On FreeBSD, -r will follow symlinks into directories. This is not true of either OS/X or recent versions of GNU grep.)
- --include '*.txt' tells grep to only return files whose names match the glob *.txt (including hidden ones like .foo.txt or .txt).
- -l tells grep to only return the names of matching files, not the match itself.
- --null tells grep to use NUL characters to separate the file names. (--null is supported by grep under GNU/Linux, MacOS and FreeBSD but not OpenBSD.)
- LINUX/UNIX tells grep to look only for files whose contents include the regex LINUX/UNIX
- . search in the current directory. You can omit it in recent versions of GNU grep, but then you'd need to pass a -- option terminator to cp to guard against file names that start with -.
xargs options and arguments
- -0 tells xargs to expect NUL-separated input.
- -r tells xargs not to run the command unless at least one file was found. (This option is not needed on either BSD or OSX and is not compatible with OSX's xargs.)
- cp -t /path/to/dest copies the directories to the target directory. (-t requires GNU cp.)

Related Solutions

GNU Find – Understanding -regex with GNU Find

Finding with ls: first things first, ls | grep cisco is a bit verbose, since cisco isn't a regular expression. Try:

ls *cisco*

Using find: along the same lines, -regex is overkill with a simple, static pattern. How about:

find -name '*cisco*'

The quotes are required so the glob is interpreted by find, not the shell. Also, -print is required for many versions of find, but is optional (and the default predicate) for others (e.g. GNU find). Feel free to add it if you need it.

If you need to search for ‘cisco’ in the full pathname, you could try this:

find -path '*cisco*'

which is equivalent to find | fgrep cisco.

Using find with regular expressions: let's do that anyway, since this is what you want. Shamelessly copying from the GNU find manpage:

-regex pattern

          File  name  matches  regular  expression  pattern.  This is a match
          on the whole path, not a search.  For example, to match a file named
          `./fubar3', you can use the regular expression `.*bar.' or `.*b.*3',
          but not `f.*r3'.

What this means is that your regular expression is wrapped in an invisible ^...$, so it must match every character in the full pathname of the file. So, as nwildner and otokan said in the comments, you should use something like:

find -regex '.*cisco.*'

And you don't even need the -regextype for something this simple.

Best Answer

Related Solutions

GNU Find – Understanding -regex with GNU Find

Related Question