UNIX for Dummies Questions & Answers

Hi,

I would like to know which files contain a certain string. If I use 'grep "string" *' only the working directory is being searched. I also want to search the subdirectories. When I use 'find . -type f -print |xargs grep "string" > dev/null' I get the message 'xargs: missing quote?'. What's up?
Should I use another command?

Thanks in advance.

Anika

grep -r "string" * will read all files under each directory recursively.

Which version of Unix does this work on? I have never encountered a grep that works like this. A portable solution is:

find . -exec grep string {} /dev/null \;

The beauty of UNIX is the 10,000 ways to do these things. Here is how I do it (one way) when I want to go down the tree:

Code:

find * | grep string

It is not the typical way, but I know many old UNIX people who do it this way. Guess we are lazy to think or type

For example, if we want to search the entire file system for libc.so.2 we would do this:

Code:

find / | grep libc.so

This way we find all the libc.so files. If we did not care about case then:

Code:

find / | grep  -i libc.so

I also like using egrep with regular expression matching for more tricky or complex matches and searches.

However, this will only find you the filenames that contain the string. It will not search for the string <I>within</I> the file, which is what the original poster was asking about.

Doing a find and then greping will certainly find the string within a string (in the file name) and works much better and faster. You are right PxT, this will not search the string within the file.

Code:

find / | grep lib

You will find a zillion occurances of the string 'lib' within a string. Here is a small sample and I've not even refined the grep or egrep (and just captured small output).

/usr/lib/gdk-pixbuf/loaders/libpixbufloader-png.so.1.0.0
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-pnm.a
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-pnm.la
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-pnm.so.1.0.0
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-ras.a
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-ras.la
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-ras.so.1.0.0
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-tiff.a
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-tiff.la
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-tiff.so.1.0.0
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-xpm.a
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-xpm.la
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-xpm.so.1.0.0
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-bmp.so
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-bmp.so.1
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-gif.so
/usr/lib/gdk-pixbuf/loaders/libpixbufloader-gif.so.1

Yes, it does not search the actual file. I normally use PERL for that and not xargs. For some strange reason, xargs and I don't gel.... when I have to search files and strings within lots of files I use command line PERL.

[Edited by Neo on 01-31-2001 at 08:52 PM]

grep -r "string" * works pretty well on Linux(RH).

However this is not a comprehensive method. But I think this could be used for what poster is mentioned since he is using '*'(this cause grep read all files under each directory recursively).

But if he uses grep -r "www" html* will only recurse into subdirectories whose names starts with "html". so if there is a subdirectory whose name is not starts with "html" will be ignored even if it has the file that contain "www" string.

my grep version: GNU grep 2.3