how to search word in group of files using command
 

hi
i am using openSUSE 10.3 & like to use power of terminal to do tasks.I want to search all files containing word 'echo' in given folder.What should be command.

Try the "grep" command. Go into the directory you mean via command line and do (//EDIT: example improved to avoid confusion):

It will go through all files inside the folder (therefore the '*') and tell you which ones contain the search pattern. For more options execute 'man grep' to read the instructions..

The grep command is very useful by the way if you want to view the output of a file and filter this output for a given word. Say you have a file called blah.conf and want to view its contents:

To find out whether or not there's a line containing the word 'example' without having to read through the entire file, you pipe it's output to the grep command using the symbol |, which returns only the lines with that word, as follows:

Try it out with a file and search term of your choice. Just thought I'd give you an example of the power of the command line :)

-A

you could do

find . | xargs grep -i pattern

it will show all the files in the current folder that have the pattern whether it is in lowercase or uppercase.

kind regards

Not a very good example. The parentheses need to be quoted to keep Bash from mistaking your intentions:

Wouldn't it be like

Like this you will have a process started for each of the file, plus 2 for find and xargs. Not very environment friendly. Also you loose information in which file the pattern was found, which can be interesting also, or maybe the only interest?

Results in 1 process start, and you will get the filenames also. If you are not interested in the whole result lines, only filenames, you can even write:

See manpage: grep(1)

No, you would use this:

But this is more reliable and less confusing:

job done!

I didn't mean the parenthesis to be part of the search pattern, in lots of cases they don't. It was just a way of highlighting where the search pattern should go. Anyway to make things clearer, I edited my first post. Thanks for the tip.

-A

is that it?

It will only search file names, not their contents.

I assumed you included the parentheses for a reason -- to suggest a regular expression. Parentheses are often used in grep searches, like this example:

This example selects files that end in common graphic file suffixes. When I see parentheses in grep examples, I assume they are meant to represent a regular-expression multiple-choice selector like this example.

In any case, the parentheses need to be managed to keep them from being interpreted by the shell -- that was my earlier point.

WHAT I HAVE LEARNT
I noticed that if I write
grep pattern *
then it gives file with corresponding lines.Also I should enclose search parameter in single or double quotes if it contains space.

You should also use quotes when the search pattern has any wildcards---and in a few other situations.

You should also read up on the difference between single and double quotes---I would start with the Bash Guide for Beginners---free at http://tldp.org