[string] How can I use grep to find a word inside a folder?

In Windows, I would have done a search for finding a word inside a folder. Similarly, I want to know if a specific word occurs inside a directory containing many sub-directories and files. My searches for grep syntax shows I must specify the filename, i.e. grep string filename.

Now, I do not know the filename, so what do I do? A friend suggested to do grep -nr string, but I don't know what this means and I got no results with it (there is no response until I issue a Ctrl + C).

1. grep -r "yourstring" * Will find "yourstring" in any files and folders

Now if you want to look for two different strings at the same time you can always use option E and add words for the search. example after the break

2. grep -rE "yourstring|yourotherstring|$" * will search for list locations where yourstring or yourotherstring matches

grep -nr search_string search_dir

will do a RECURSIVE (meaning the directory and all it's sub-directories) search for the search_string. (as correctly answered by usta).

The reason you were not getting any anwers with your friend's suggestion of:

grep -nr string

is because no directory was specified. If you are in the directory that you want to do the search in, you have to do the following:

grep -nr string .

It is important to include the '.' character, as this tells grep to search THIS directory.

Similar to the answer posted by @eLRuLL, a easier way to specify a search that respects word boundaries is to use the -w option:

grep -wnr "yourString" .

The following sample looks recursively for your search string in the *.xml and *.js files located somewhere inside the folders path1, path2 and path3.

grep -r --include=*.xml --include=*.js "your search string" path1 path2 path3

So you can search in a subset of the files for many directories, just providing the paths at the end.

Why not do a recursive search to find all instances in sub directories:

grep -r 'text' *

This works like a charm.

Another option that I like to use:

find folder_name -type f -exec grep your_text  {} \;

-type f returns you only files and not folders

-exec and {} runs the grep on the files that were found in the search (the exact syntax is "-exec command {}").

grep -R "string" /directory/

-R follows also symlinks when -r does not.

Run(terminal) the following command inside the directory. It will recursively check inside subdirectories too.

grep -r 'your string goes here' * 

The answer you selected is fine, and it works, but it isn't the correct way to do it, because:

grep -nr yourString* .

This actually searches the string "yourStrin" and "g" 0 or many times.

So the proper way to do it is:

grep -nr \w*yourString\w* .

This command searches the string with any character before and after on the current folder.

Don't use grep. Download Silver Searcher or ripgrep. They're both outstanding, and way faster than grep or ack with tons of options.

There's also:

find directory_name -type f -print0 | xargs -0 grep -li word

but that might be a bit much for a beginner.

find is a general purpose directory walker/lister, -type f means "look for plain files rather than directories and named pipes and what have you", -print0 means "print them on the standard output using null characters as delimiters". The output from find is sent to xargs -0 and that grabs its standard input in chunks (to avoid command line length limitations) using null characters as a record separator (rather than the standard newline) and the applies grep -li word to each set of files. On the grep, -l means "list the files that match" and -i means "case insensitive"; you can usually combine single character options so you'll see -li more often than -l -i.

If you don't use -print0 and -0 then you'll run into problems with file names that contain spaces so using them is a good habit.

GREP: Global Regular Expression Print/Parser/Processor/Program.
You can use this to search the current directory.
You can specify -R for "recursive", which means the program searches in all subfolders, and their subfolders, and their subfolder's subfolders, etc.

grep -R "your word" .

-n will print the line number, where it matched in the file.
-i will search case-insensitive (capital/non-capital letters).

grep -inR "your regex pattern" .

grep -nr string my_directory

Additional notes: this satisfies the syntax grep [options] string filename because in Unix-like systems, a directory is a kind of file (there is a term "regular file" to specifically refer to entities that are called just "files" in Windows).

grep -nr string reads the content to search from the standard input, that is why it just waits there for input from you, and stops doing so when you press ^C (it would stop on ^D as well, which is the key combination for end-of-file).