i have to search for a particular text in files and for that im using grep command but it searches only in current folder.What i want is that using a single grep command i can search a particular thing in the current folder as well as in all of its sub folders.How can i do that???
POSIX grep does not support recursive searching - the GNU version of grep does.
find . -type f -exec grep 'pattern' {} \;
would be runnable on any POSIX compliant UNIX.
man grep says
-R, -r, --recursive
Read all files under each directory, recursively; this is
equivalent to the -d recurse option.
And even more common is to use find with xargs, say
find <dir> -type f -name <shellglob> -print0 | xargs grep -0
where -print0 and -0, respectively, would use null char to separate entries in order to avoid issues with filenames having space characters.
Related
I want to grep for a string in all the files which have a particular patter in their name and is case-insensitive.
For eg if I have two files ABC.txt and aBc.txt, then I want something like
grep -i 'test' *ABC*
The above command should look in both the files.
You can use find and then grep on the results of that:
find . -iname "*ABC*" -exec grep -i "test" {} \;
Note that this will run grep once on each file found. If you want to run grep once on all the files (in which case you risk running into the command line length limit), you can use a plus at the end:
find . -iname "*ABC*" -exec grep -i "test" {} \+
You can also use xargs to process a really large number of results more efficiently:
find . -iname "*ABC*" -print0 | xargs -0 grep -i test
The -print0 makes find output 0-terminated results, and the -0 makes xargs able to deal with this format, which means you don't need to worry about any special characters in the filenames. However, it is not totally portable, since it's a GNU extension.
If you don't have a find that supports -print0 (for example SVR4), you can still use -exec as above or just
find . -iname "*ABC*" | xargs grep -i test
But you should be sure your filenames don't have newlines in them, otherwise xargs will treat each line of a filename as a new argument.
You should use find to match file and search string that you want with command grep which support regular expression, for your question, you should input command like below:
find . -name "*ABC*" -exec grep \<test\> {} \;
I am running -> "find . -name '*.txt'" command and getting list of files.
I am getting below mention output:
./bsd/contrib/amd/ldap-id.txt
./bsd/contrib/expat/tests/benchmark/README.txt
./bsd/contrib/expat/tests/README.txt
./bsd/lib/libc/softfloat/README.txt
and so on,
Out of these files how can i run grep command and read contents and filter only those files which have certain keyword? for e.g. "version" in it.
xargs is a great way to accomplish this, and its already been covered.
The -exec option of find is also useful for this. It will perform a command over all files returned from find.
To invoke grep as few times as possible, passing multiple filenames to each call:
find . -name '*.txt' -exec grep -H 'foo' {} +
Alternately, to invoke grep exactly once for each file found:
find . -name '*.txt' -exec grep -H 'foo' {} ';'
In either case, {} is like a placeholder for the values from find; if your shell is zsh, it may be necessary to escape it, as in '{}'.
There are several ways to accomplish this.
If there are non-.txt files which might usefully contain the keyword:
grep -r KEYWORD *
This uses the recursive directory search option of grep.
To search only .txt files:
find . -name '*.txt' -exec grep KEYWORD {} \;
or
find . -name '*.txt' -exec grep KEYWORD {} +
or
find . -execdir grep KEYWORD {}
The first runs grep for each matching file. The second runs grep much fewer times, accumulating many matched files before invoking grep. The third form runsgrep` once in every directory.
There is usually a function built into find for that, but to be portable across platforms, I typically use xargs. Say you want to find all the xml files in or below the current directly and get a list of each occurrence of 'foo', you can do this:
find ./ -type f -name '*.xml' -print0 | xargs -0 -n 1 grep -H foo
It should be self-explanatory except for the -print0, which separates filenames with NULs rather than newlines, and the -0, which tells xargs to use those NULs rather than interpreting spaces and quotes as syntax (which can confuse it if filenames contain either).
I want to search an expression say "abcd" in all files of a directory but exclude some file of a certain type in my search
like
grep -rn 'abcd' *
But the result should not include expression found in files with extensions .js and .h. How will I do that?
use the --exclude option
grep 'your string here' -r --exclude=\*.{js,h}
So, at this point I typically advise to use ack, which is like grep, but has a lot of built-in features like file type selection.
But with grep, and a bit of shell magic, this can work:
find -not -iname '*.h' -not -iname '*.js' -print0 | xargs -0 grep -rn 'abcd'
I am successfully using find to create a list of all files in the current subdirectory, excluding those in the subdirectory "cache." Here's my first bit of code:
find . -wholename './cach*' -prune -o -print
I now wish to pipe this into a grep command. It seems like that should be simple:
find . -wholename './cach*' -prune -o -print | xargs grep -r -R -i "samson"
... but this is returning results that are mostly from the cache directory. I've tried removing the xargs reference, but that does what you'd expect, running the grep on text of the file names, rather than on the files themselves. My goal is to find "samson" in any files that aren't cached content.
I'll probably get around this issue by just using doubled greps in this instance, but I'm very curious about why this one-liner behaves this way. I'd love to hear thoughts on a way to modify it while still using these two commands (as there are speed advantages to doing it this way).
(This is in CentOS 5, btw.)
The wholename match may be the reason why it's still including "cache" files. If you're executing the find command in the directory that contains the "cache" folder, it should work. If not, try changing it to -name '*cache*' instead.
Also, you do not need the -r or -R for your grep, that tells it to recurse through directories - but you're testing individual files.
You can update your command using the piped version, or a single-command:
find . -name '*cache*' -prune -o -print0 | xargs -0 grep -il "samson"
or
find . -name '*cache*' -prune -o -exec grep -iq "samson" {} \; -print
Note, the -l in the first command tells grep to "list the file" and not the line(s) that match. The -q in the second does the same; it tells grep to respond quietly so find will then just print the filename.
You've told grep itself to recurse (twice! -r and -R are synonyms). Since one of the arguments you're passing is . (the top directory), grep is searching in every file (some of them twice, or even more if they're in subdirectories).
If you're going to use find and grep, do this:
find . -path './cach*' -prune -o -print0 | xargs -0 grep -i "samson"
Using -print0 and -0 makes your script work even with file names that contain spaces or punctuation characters.
However, you probably don't need to bother with find here, since GNU grep is capable of excluding directories:
grep -R --exclude-dir='cach*' -i "samson" .
(This also excludes ./deeply/nested/directory/cache. If you only want to exclude cache directories at the toplevel, use find as you did.)
Use the -exec option on find instead of piping them to another command. From there you can use grep "samson" {} \; to look for samson in each file listed.
For example:
find . -wholename './cach*' -prune -o -exec grep "samson" "{}" +
I have had to do this several times, usually when trying to find in what files a variable or a function is used.
I remember using xargs with grep in the past to do this, but I am wondering if there are any easier ways.
grep -r REGEX .
Replace . with whatever directory you want to search from.
The portable method* of doing this is
find . -type f -print0 | xargs -0 grep pattern
-print0 tells find to use ASCII nuls as the separator and -0 tells xargs the same thing. If you don't use them you will get errors on files and directories that contain spaces in their names.
* as opposed to grep -r, grep -R, or grep --recursive which only work on some machines.
This is one of the cases for which I've started using ack (http://petdance.com/ack/) in lieu of grep. From the site, you can get instructions to install it as a Perl CPAN component, or you can get a self-contained version that can be installed without dealing with dependencies.
Besides the fact that it defaults to recursive searching, it allows you to use Perl-strength regular expressions, use regex's to choose files to search, etc. It has an impressive list of options. I recommend visiting the site and checking it out. I've found it extremely easy to use, and there are tips for integrating it with vi(m), emacs, and even TextMate if you use that.
If you're looking for a string match, use
fgrep -r pattern .
which is faster than using grep.
More about the subject here: http://www.mkssoftware.com/docs/man1/grep.1.asp
grep -r if you're using GNU grep, which comes with most Linux distros.
On most UNIXes it's not installed by default so try this instead:
find . -type f | xargs grep regex
If you use the zsh shell you can use
grep REGEX **/*
or
grep REGEX **/*.java
This can run out of steam if there are too many matching files.
The canonical way though is to use find with exec.
find . -name '*.java' -exec grep REGEX {} \;
or
find . -type f -exec grep REGEX {} \;
The 'type f' bit just means type of file and will match all files.
I suggest changing the answer to:
grep REGEX -r .
The -r switch doesn't indicate regular expression. It tells grep to recurse into the directory provided.
This is a great way to find the exact expression recursively with one or more file types:
find . \\( -name '\''*.java'\'' -o -name '\''*.xml'\'' \\) | xargs egrep
(internal single quotes)
Where
-name '\''*.<filetype>'\'' -o
(again single quotes here)
is repeated in the parenthesis ( ) for how many more filetypes you want to add to your recursive search
an alias looks like this in bash
alias fnd='find . \\( -name '\''*.java'\'' -o -name '\''*.xml'\'' \\) | xargs egrep'