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).
grep -nr 'yourString*' .
The dot at the end searches the current directory. Meaning for each parameter:
-n Show relative line number in the file
'yourString*' String for search, followed by a wildcard character
-r Recursively search subdirectories listed
. Directory for search (current directory)
grep -nr 'MobileAppSer*' . (Would find MobileAppServlet.java or MobileAppServlet.class or MobileAppServlet.txt; 'MobileAppASer*.*' is another way to do the same thing.)
To check more parameters use man grep command.
grep -nr MobileAppSer* . 1. Assume we have 3 files in the current directory matching MobileAppSer* wildcard pattern: named MobileAppServlet.java, MobileAppServlet.class, MobileAppServlet.txt. Then grep will be invoked like this: grep -nr MobileAppServlet.class MobileAppServlet.java MobileAppServlet.txt .. It means search for text "MobileAppServlet.class" in files MobileAppServlet.java, MobileAppServlet.txt, and elsewhere in the current directory - which surely isn't what the user wants here. –
Grugru MobileAppSer* wildcard pattern, grep will receive the argument MobileAppSer* as-is and thus will take it as search for text "MobileAppSe" followed by 0 or more occurrences of "r", so it will attempt to find texts "MobileAppSe", "MobileAppSer", "MobileAppSerr", "MobileAppSerrr", etc. in current directory's files contents - not what the user wants either. –
Grugru grep -nr 'yourString*' . and got some files with "binary file matches". You can add --text or -a to prevent this: grep -anr 'yourString*' . –
Adelleadelpho grep -anr 'yourString' . –
Biform 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).
grep -inr "my word" . –
Grugru -r for grep means search in subdirectories recursively and -n means prefix each line of output with the corresponding line number of the file which contains that line. man grep describes all of this, and much more. –
Grugru 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 -inR "[0-9a-fA-F]{32}" . helps find hashes (which are hex strings) in the files within the current directory. https://mcmap.net/q/21349/-regular-expression-for-a-hexadecimal-number –
Met 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 then 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.
man find from the command line to see what options your find supports. –
Flavorous 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.
Why not do a recursive search to find all instances in sub directories:
grep -r 'text' *
This works like a charm.
Similar to the answer posted by @eLRuLL, an easier way to specify a search that respects word boundaries is to use the -w option:
grep -wnr "yourString" .
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 "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
grep -rE "yourstring|yourotherstring|$" * will search for list locations where yourstring or yourotherstring matchesgrep -R "string" /directory/
-R follows also symlinks when -r does not.
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.
grep -nr yourString works too, as it looks for the bare yourString anywhere in the line (or at least it does on my system, OSX Lion) –
Futile 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.
Run(terminal) the following command inside the directory. It will recursively check inside subdirectories too.
grep -r 'your string goes here' *
Don't use grep. Download Silver Searcher or ripgrep. They're both outstanding, and way faster than grep or ack with tons of options.
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*? It will either result in shell wildcard expansion (if there are filenames matching the wildcard pattern), or grep will take it as 0-or-more repetition operator for the character preceding*. – Grugru