I would like to do something like:
find . -iname "*Advanced*Linux*Program*" -exec kpdf {} & \;
Possible? Some other comparable method available?
Firstly, it won't work as you've typed, because the shell will interpret it as
find . -iname "*Advanced*Linux*Program*" -exec kpdf {} &
\;
which is an invalid find run in the background, followed by a command that doesn't exist.
Even escaping it doesn't work, since find -exec actually execs the argument list given, instead of giving it to a shell (which is what actually handles & for backgrounding).
Once you know that that's the problem, all you have to do is start a shell to give these commands to:
find . -iname "*Advanced*Linux*Program*" -exec sh -c '"$0" "$#" &' kpdf {} \;
On the other hand, given what you're trying to do, I would suggest one of
find ... -exec kfmclient exec {} \; # KDE
find ... -exec gnome-open {} \; # Gnome
find ... -exec xdg-open {} \; # any modern desktop
which will open the file in the default program as associated by your desktop environment.
If your goal is just not having to close one pdf in order to see the next one as opposed to display each pdf in its own separate instance, you might try
find . -iname "*Advanced*Linux*Program*" -exec kpdf {} \+ &
With the plussed variant, -exec builds the command line like xargs would so all the files found would be handed to the same instance of kpdf. The & in the end then affects the whole find. With very large numbers of files found it might still open them in batches because command lines grow too long, but with respect to ressource consumption on your system this may even be a good thing. ;)
kpdf has to be able to take a list of files on the command line for this to work, as I don't use it myself I don't know this.
Related
This problem has been discussed extensively but I couldn't find a solution that would help me.
I'm trying to selectively copy files from a directory tree into a specific folder. After reading some Q&A, here's what I tried:
cp `find . -name "*.pdf" -type f` ../collect/
I am in the right parent directory and there indeed is a collect directory a level above. Now I'm getting the error: cp: invalid option -- 'o'
What is going wrong?
To handle difficult file names:
find . -name "*.pdf" -type f -exec cp {} ../collect/ \;
By default, find will print the file names that it finds. If one uses the -exec option, it will instead pass the file names on to a command of your choosing, in this case a cp command which is written as:
cp {} ../collect/ \;
The {} tells find where to insert the file name. The end of the command given to -exec is marked by a semicolon. Normally, the shell would eat the semicolon. So, we escape the semicolon with a backslash so that it is passed as an argument to the find command.
Because find gives the file name to cp directly without interference from the shell, this approach works for even the most difficult file names.
More efficiency
The above runs cp on every file found. If there are many files, that would be a lot of processes started. If one has GNU tools, that can be avoided as follows:
find . -name '*.pdf' -type f -exec cp -t ../collect {} +
In this variant of the command, find will supply many file names for each single invocation of cp, potentially greatly reducing the number of processes that need to be started.
I'm probably missing something, but this oneliner in a bash-script to cycle through some scripts that dump data from different sources:
find . -name 'dump-*.sh' -exec {} "$DUMP_LOG" &>>"$DUMP_LOG" \;
will work when I execute the bash-script containing this oneliner directly, but it doesn't work when I invoke it as the cmd_preexec in rsnapshot. It doesn't spawn any errors, it just doesn't do anything.
I tried adding '(/bin/)bash -c', like this:
find . -name 'dump-*.sh' -exec bash -c '{} "$DUMP_LOG" &>>"$DUMP_LOG"' \;
but then I get an error about '(/bin/)bash not existing, even if Irun the script directly.
OK, silly me. Of course the first parameter of the find-cmd needs the working directory.
find /usr/local/sbin -name 'dump-*.sh' -exec {} "$DUMP_LOG" &>>"$DUMP_LOG" \;
has solved the problem.
I am trying to make copies of certain file and let them have a prefix.
in order to do it I thought of using find. for our use, let's call them kuku files and I want them to have a "foo" prefix:
find . -maxdepth 1 -name "kuku*" -exec cp '{}' foo_'{}' \;
but it doesn't work because the find always starts the results with ./ so i get a lot of error messages saying "cp: cannot create regular file `foo_./kuku...`: No such file or directory".
the problem is solvable by using foreach f (`ls`) and than using grep and the status var, but it is cumbersome and I want to learn a better solution (and improve my knowledge of the find command along the way...).
update foreach solution (which I don't like and want your help in finding a replacement):
foreach f (`ls`)
echo $f | grep -lq kuku
if (! $status) then
cp $f foo_$f
endif
end
but this is UGLY! (end of update)
as the header says, I'm using csh - not because I love it, just because that's what we use at work...
update
trying to use basename as a solution, because find -exec basename '{}' \; removes the ./ prefix, but i failed using the basename inside the find with backticks (`), meaning that
find -name "kuku*" -exec cp '{}' foo_`basename '{}` \;
simply doesn't work.
Here you go.. I have tested in my linux box
find . -name "kuku*" -exec sh -c 'cp {} foo_`basename {}`' \;
It seems like I am unable to find a direct answer to this question.
I appreciate your help.
I'm trying to find all files with a specific name in a directory, read the last 1000 lines of the file and copy it in to a new file in the same directory. As an example:
Find all files names xyz.log in the current directory, copy the last 1000 lines to file abc.log (which doesn't exist).
I tried to use the following command with no luck:
find . -name "xyz.log" -execdir tail -1000 {} > abc.log \;
The problem I'm having is that for all the files in the current directory, they all write to abc.log in the CURRENT directory and not in the directory where xyz.log resides. Clearly the find with execdir is first executed and then the output is redirected to abc.log.
Can you guys suggest a way to fix this? I appreciate any information/help.
EDIT- I tried find . -name "xyz.log" -execdir sh -c "tail -1000 {} > abc.log" \; as suggested by some of the friends, but it gives me this error: sh: ./tail: No such file or directory error message. Do you guys have any idea what the problem is?
Luckily the solution to use -printf is working fine.
The simplest way is this:
find . -name "xyz.log" -execdir sh -c 'tail -1000 "{}" >abc.log' \;
A more flexible alternative is to first print out the commands and then execute them all with sh:
find . -name "xyz.log" -printf 'tail -1000 "%p" >"%h/abc.log"\n' | sh
You can remove the | sh from the end when you're trying it out/debugging.
There is a bug in some versions of findutils (4.2 and 4.3, though it was fixed in some 4.2.x and 4.3.x versions) that cause execdir arguments that contain {} to be prefixed with ./ (instead of the prefix being applied only to {} it is applied to the whole quoted string). To work around this you can use:
find . -name "xyz.log" -execdir sh -c 'tail -1000 "$1" >abc.log' sh {} \;
sh -c 'script' arg0 arg1 runs the sh script with arg0, arg1, etc. passed to it. By convention, arg0 is the name of the executable (here, "sh"). From the script you can access the arguments using $0 (corresponding to "sh"), $1 (corresponding to find's expansion of {}), etc.
The redirect isn't passed into execdir, so abc.log shows up in the directory you run the command in. -execdir also doesn't like embedded redirects. but you can workaround the problem by passing -execdir a shell command with a redirect embedded, like this:
find . -name "xyz.log" -execdir sh -c '/usr/bin/tail -1000 {} > abc.log' \;
Much credit to this blog post (not mine):
http://www.microhowto.info/howto/act_on_all_files_in_a_directory_tree_using_find.html
Edit
I put the full path to tail in the command (assuming it's in /usr/bin on your system), since sh may load a .profile with a PATH that differs from your current shell.
Here's another non-find (well, sorta - it still uses find but doesn't try to shoehorn find into doing the whole thing):
while read f
do
d=$(dirname "${f}")
tail -n 1000 "${f}" > "${d}/abc.log"
done < <(find . -type f -name xyz.log -print)
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 +.