How can I use find results as a command line argument for another process?
For example:
find -type f -iname "server*error*log" | vim ??
How to make vim to open returned filename?
You need to use the -exec option of find:
find -type f -iname "server*error*log" -exec vim {} \;
The placeholder {} will get replaced by the actual filename. The -exec command needs to get terminated with the \;.
If you want not just one file, but many, to be acted on by one program (in your case editing in Vim), I think you want to pass it to xargs:
find -type f -iname "server*error*log" | xargs vim
Related
I'm trying to work out a command which deletes sql files older than 15 days.
The find part is working but not the rm.
rm -f | find -L /usr/www2/bar/htdocs/foo/rsync/httpdocs/db_backups -type f \( -name '*.sql' \) -mtime +15
It kicks out a list of exactly the files I want deleted but is not deleting them. The paths are correct.
usage: rm [-f | -i] [-dIPRrvW] file ...
unlink file
/usr/www2/bar/htdocs/foo/rsync/httpdocs/db_backups/20120601.backup.sql
...
/usr/www2/bar/htdocs/foo/rsync/httpdocs/db_backups/20120610.backup.sql
What am I doing wrong?
You are actually piping rm's output to the input of find. What you want is to use the output of find as arguments to rm:
find -type f -name '*.sql' -mtime +15 | xargs rm
xargs is the command that "converts" its standard input into arguments of another program, or, as they more accurately put it on the man page,
build and execute command lines from standard input
Note that if file names can contain whitespace characters, you should correct for that:
find -type f -name '*.sql' -mtime +15 -print0 | xargs -0 rm
But actually, find has a shortcut for this: the -delete option:
find -type f -name '*.sql' -mtime +15 -delete
Please be aware of the following warnings in man find:
Warnings: Don't forget that the find command line is evaluated
as an expression, so putting -delete first will make find try to
delete everything below the starting points you specified. When
testing a find command line that you later intend to use with
-delete, you should explicitly specify -depth in order to avoid
later surprises. Because -delete implies -depth, you cannot
usefully use -prune and -delete together.
P.S. Note that piping directly to rm isn't an option, because rm doesn't expect filenames on standard input. What you are currently doing is piping them backwards.
find /usr/www/bar/htdocs -mtime +15 -exec rm {} \;
Will select files in /usr/www/bar/htdocs older than 15 days and remove them.
Another simpler method is to use locate command. Then, pipe the result to xargs.
For example,
locate file | xargs rm
Use xargs to pass arguments, with the option -rd '\n' to ignore spaces in names:
"${command}" | xargs -rd '\n' rm
Include --force if you want to also remove read only files.
Assuming you aren't in the directory containing the *.sql backup files:
find /usr/www2/bar/htdocs/foo/rsync/httpdocs/db_backups/*.sql -mtime +15 -exec rm -v {} \;
The -v option above is handy it will verbosely output which files are being deleted as they are removed.
I like to list the files that will be deleted first to be sure. E.g:
find /usr/www2/bar/htdocs/foo/rsync/httpdocs/db_backups/*.sql -mtime +15 -exec ls -lrth {} \;
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 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
There's a way to replace all occurencies of a string in files in Vim using a combination of args and argdo commands. Unfortunately there's a drawback with this solution: It will open all files which may be a problem for large projects. Does anyone know more compact and memory efficient way?
find projectfolder -type f -exec grep -Iq 'pattern' {} \; -exec vim {} +
Here's how I do it (when I'm not using perl):
find . -name '*.java' -exec vim +'%s/OldName/NewName/gc' +'wq' {} \;
i.e. replace "OldName" with "NewName" in all "*.java" files, but prompt me for confirmation for each substitution.
I want to know exactly what {} \; and {} \+ and | xargs ... do. Please clarify these with explanations.
Below 3 commands run and output same result but the first command takes a little time and the format is also little different.
find . -type f -exec file {} \;
find . -type f -exec file {} \+
find . -type f | xargs file
It's because 1st one runs the file command for every file coming from the find command. So, basically it runs as:
file file1.txt
file file2.txt
But latter 2 find with -exec commands run file command once for all files like below:
file file1.txt file2.txt
Then I run the following commands on which first one runs without problem but second one gives error message.
find . -type f -iname '*.cpp' -exec mv {} ./test/ \;
find . -type f -iname '*.cpp' -exec mv {} ./test/ \+ #gives error:find: missing argument to `-exec'
For command with {} \+, it gives me the error message
find: missing argument to `-exec'
why is that? can anyone please explain what am I doing wrong?
The manual page (or the online GNU manual) pretty much explains everything.
find -exec command {} \;
For each result, command {} is executed. All occurences of {} are replaced by the filename. ; is prefixed with a slash to prevent the shell from interpreting it.
find -exec command {} +
Each result is appended to command and executed afterwards. Taking the command length limitations into account, I guess that this command may be executed more times, with the manual page supporting me:
the total number of invocations of the command will be much less than the number of matched files.
Note this quote from the manual page:
The command line is built in much the same way that xargs builds its command lines
That's why no characters are allowed between {} and + except for whitespace. + makes find detect that the arguments should be appended to the command just like xargs.
The solution
Luckily, the GNU implementation of mv can accept the target directory as an argument, with either -t or the longer parameter --target. It's usage will be:
mv -t target file1 file2 ...
Your find command becomes:
find . -type f -iname '*.cpp' -exec mv -t ./test/ {} \+
From the manual page:
-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.
-exec command {} +
This variant of the -exec action runs the specified command on the selected files, but the command line is built by appending each selected file name at the end; the total number of invocations of the command will be much less than the number of matched files. The command line is built in much the same way that xargs builds its command lines. Only one instance of `{}' is allowed within the command. The command is executed in the starting directory.
I encountered the same issue on Mac OSX, using a ZSH shell: in this case there is no -t option for mv, so I had to find another solution.
However the following command succeeded:
find .* * -maxdepth 0 -not -path '.git' -not -path '.backup' -exec mv '{}' .backup \;
The secret was to quote the braces. No need for the braces to be at the end of the exec command.
I tested under Ubuntu 14.04 (with BASH and ZSH shells), it works the same.
However, when using the + sign, it seems indeed that it has to be at the end of the exec command.
The standard equivalent of find -iname ... -exec mv -t dest {} + for find implementations that don't support -iname or mv implementations that don't support -t is to use a shell to re-order the arguments:
find . -name '*.[cC][pP][pP]' -type f -exec sh -c '
exec mv "$#" /dest/dir/' sh {} +
By using -name '*.[cC][pP][pP]', we also avoid the reliance on the current locale to decide what's the uppercase version of c or p.
Note that +, contrary to ; is not special in any shell so doesn't need to be quoted (though quoting won't harm, except of course with shells like rc that don't support \ as a quoting operator).
The trailing / in /dest/dir/ is so that mv fails with an error instead of renaming foo.cpp to /dest/dir in the case where only one cpp file was found and /dest/dir didn't exist or wasn't a directory (or symlink to directory).
find . -name "*.mp3" -exec mv --target-directory=/home/d0k/Музика/ {} \+
no, the difference between + and \; should be reversed. + appends the files to the end of the exec command then runs the exec command and \; runs the command for each file.
The problem is find . -type f -iname '*.cpp' -exec mv {} ./test/ \+ should be find . -type f -iname '*.cpp' -exec mv {} ./test/ + no need to escape it or terminate the +
xargs I haven't used in a long time but I think works like +.