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).
Related
I would like to go through all the files in the current directory (or sub-directories) and echoes me back the name of files only if they contain certain words.
More detail:
find -type f -name "*hello *" will give me all file names that have "hello" in their names. But instead of that, I want to search through the files and if that file's content contains "hello" then prints out the name of the file.
Is there a way to approach this?
You can use GNU find and GNU grep as
find /path -type f -exec grep -Hi 'hello' {} +
This is efficient in a way that it doesn't invoke as many grep instances to as many files returned from find. This works in an underlying assumption that find returns a set of files for grep to search on. If you are unsure if the files may not be available, as a fool-proof way, you can use xargs with -r flag, in which case the commands following xargs are executed only if the piped commands return any results
find /path -type f | xargs -r0 grep -Hi 'hello'
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'm trying to count the total lines in the files within a directory. To do this I am trying to use a combination of find and wc. However, when I run find . -exec wc -l {}\;, I recieve the error find: missing argument to -exec. I can't see any apparent issues, any ideas?
You simply need a space between {} and \;
find . -exec wc -l {} \;
Note that if there are any sub-directories from the current location, wc will generate an error message for each of them that looks something like that:
wc: ./subdir: Is a directory
To avoid that problem, you may want to tell find to restrict the search to files :
find . -type f -exec wc -l {} \;
Another note: good idea using the -exec option . Too many times people pipe commands together thinking to get the same result, for instance here it would be :
find . -type f | xargs wc -l
The problem with piping commands in such a manner is that it breaks if any files has spaces in it. For instance here if a file name was "a b" , wc would receive "a" and then "b" separately and you would obviously get 2 error messages: a: no such file and b: no such file.
Unless you know for a fact that your file names never have any spaces in them (or non-printable characters), if you do need to pipe commands together, you need to tell all the tools you are piping together to use the NULL character (\0) as a separator instead of a space. So the previous command would become:
find . -type f -print0 | xargs -0 wc -l
With version 4.0 or later of bash, you don't need your find command at all:
shopt -s globstar
wc -l **/*
There's no simple way to skip directories, which as pointed out by Gui Rava you might want to do, unless you can differentiate files and directories by name alone. For example, maybe directories never have . in their name, while all the files have at least one extension:
wc -l **/*.*
I want to insert a line into the start of multiple specified type files, which the files are located in current directory or the sub dir.
I know that using
find . -name "*.csv"
can help me to list the files I want to use for inserting.
and using
sed -i '1icolumn1,column2,column3' test.csv
can use to insert one line at the start of file,
but now I do NOT know how to pipe the filenames from "find" command to "sed" command.
Could anybody give me any suggestion?
Or is there any better solution to do this?
BTW, is it work to do this in one line command?
Try using xargs to pass output of find and command line arguments to next command, here sed
find . -type f -name '*.csv' -print0 | xargs -0 sed -i '1icolumn1,column2,column3'
Another option would be to use -exec option of find.
find . -type f -name '*.csv' -exec sed -i '1icolumn1,column2,column3' {} \;
Note : It has been observed that xargs is more efficient way and can handle multiple processes using -P option.
This way :
find . -type f -name "*.csv" -exec sed -i '1icolumn1,column2,column3' {} +
-exec do all the magic here. The relevant part of man find :
-exec command ;
Execute command; true if 0 status is returned. All following arguments
to find are taken to be arguments to the command until an argument consisting
of `;' is encountered. The string `{}' is replaced by the current file name
being processed everywhere it occurs in the arguments to the command, not just
in arguments where it is alone, as in some versions of find. Both of
these constructions might need to be escaped (with a `\') or quoted to protect
them from expansion by the shell. See the EXAMPLES section for examples of
the use of the -exec option. The specified command is run once for each
matched file. The command is executed in the starting directory. There
are unavoidable security problems surrounding use of the -exec action;
you should use the -execdir option instead
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" "{}" +