Find files in a dir, executing a command with execdir and redirecting - linux

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)

Related

How to use grep to reverse search files in a folder

I'm trying to create a script which will find missing topics from multiple log files. These logfiles are filled top down, so the newest logs are at the bottom of the file. I would like to grep only the last line from this file which includes UNKNOWN_TOPIC_OR_PARTITION. This should be done in multiple files with completely different names. Is grep the best solution or is there another solution that suits my needs. I already tried adding tail, but that doesn't seem to work.
missingTopics=$(grep -Ri -m1 --exclude=*.{1,2,3,4,5} UNKNOWN_TOPIC_OR_PARTITION /app/tibco/log/tra/domain/)
You could try a combination of find, tac and grep:
find /app/tibco/log/tra/domain -type f ! -name '*.[1-5]' -exec sh -c \
'tac "$1" | grep -im1 UNKNOWN_TOPIC_OR_PARTITION' "sh" '{}' \;
tac prints files in reverse, the -exec sh -c SCRIPT "sh" '{}' \; action of find executes the shell SCRIPT each time a file matching the previous tests is found. The SCRIPT is executed with "sh" as parameter $0 and the path of the found file as parameter $1.
If performance is an issue you can probably improve it with:
find . -type f ! -name '*.[1-5]' -exec sh -c 'for f in "$#"; do \
tac "$f" | grep -im1 UNKNOWN_TOPIC_OR_PARTITION; done' "sh" '{}' +
which will spawn less shells. If security is also an issue you can also replace -exec by -execdir (even if with this SCRIPT I do not immediately see any exploit).

Bash find- is showing the files but returning no such file or directory

I have a bash script I cannot get working. I am a dead set beginner in bash this is actually the first script I've ever used. I'm trying to get omxplayer to play a list of files in a directory. When the script runs I get feedback showing the file then the error that there is no such file or directory. Please help me?
#!/bin/sh
find /media/pi/88DC-E668/MP3/ -name "*.mp3" -exec PLAY={} \;; omxplayer "$PLAY";
This is the echo:
find: `PLAY=/media/pi/88DC-E668/MP3/Dance.mp3': No such file or directory
find: `PLAY=/media/pi/88DC-E668/MP3/Whitemary.mp3': No such file or directory
find: `PLAY=/media/pi/88DC-E668/MP3/Limo.mp3': No such file or directory
find: `PLAY=/media/pi/88DC-E668/MP3/Silo.mp3': No such file or directory
File "" not found.
Easy way:
find /media/pi/88DC-E668/MP3 -name \*.mp3 -exec omxplayer {} \;
or
while IFS= read -r -d '' mp3
do
omxplayer "$mp3"
done < <(find /media/pi/88DC-E668/MP3 -name \*.mp3 -print0)
or
find /media/pi/88DC-E668/MP3 -name \*.mp3 -print0 | xargs -0 -n1 omxplayer
You can omit the -n1 if the omxplayer could handle multiple filenames. In such case the 1st could be written as:
find /media/pi/88DC-E668/MP3 -name \*.mp3 -exec omxplayer {} +
but the simplest probably will be
#shopt -s globstar #the default is on
for mp3 in /media/pi/88DC-E668/MP3/{,**/}*.mp3
do
omxplayer "$mp3"
done
EDIT I stand corrected, but won't delete the answer as you can also learn from the mistakes of others. See comment and rather use this answer :)
So please don't do it like this, as this is a typical "happy path" solution - meaning: it works if you know what you're doing and you know your paths (e.g. that they don't contain spaces). I keep forgetting that many people don't know yet that spaces in paths are evil.
Just use xargs to pass what you found to your player like this:
#!/bin/sh
find /media/pi/88DC-E668/MP3/ -name "*.mp3" | xargs omxplayer
The -exec foo part means run the command foo for each path found.
In your case, -exec PATH={}, the {} part is replaced with the path name, ending up with something like -exec PATH=/media/pi/88DC-E668/MP3/Dance.mp3, and so then find tries to run the command PATH=/media/pi/88DC-E668/MP3/Dance.mp3 which fails because there isn't actually any such program to execute.
xargs is the usual way to do what you're trying to do, as described in another comment already.
You could also do:
find /media/pi/88DC-E668/MP3/ -name \*.mp3 |
while read f; do
omxplayer "$f"
done

Embedding a bash command inside the mv command

I have a directory that contains a list of files having the following format:
240-timestamp1.ts
240-timestamp2.ts
...
360-timestamp1.ts
360-timestamp2.ts
Now, I want to implement a bash command which matches the files that start with '240' and renames them so that instead of '240-timestampX.ts' the files look like '240-human-readable-timestampX.ts'.
I have tried the following:
find . -maxdepth 1 -mmin +5 -type f -name "240*"
-exec mv $0 {$0/240-***and here I want to insert
either stat -c %y filename or date -d #timestampX***} '{}' \;
I stuck here because I don't know if I can embed a bash command inside the mv command. I know the task may look a bit confusing and over-complicated, but I would like to know if it is possible to do so. Of course I can create a bash script that would go through all the files in the directory and while loop them with changing their respective names, but somehow I think that a single command would be more efficient (even if less readable).
The OS is Linux Ubuntu 12.04.5
The shell is bash
Thank you both Kenavoz and Kurt Stutsman for the proposed solutions. Both your answers perform the task; however, I marked Kenavoz's answer as the accepted one because of the degree of similarity between my question and Kenavoz's answer. Even if it is indeed possible to do it in a cleaner way with omitting the find command, it is necessary in my case to use the respective command because I need to find files older than X units of time. So thank you both once again!
In case you want to keep your mmin option, your can use find and process found files with a bash command using xargs :
find . -maxdepth 1 -mmin +5 -type f -name "240*.ts" | xargs -L 1 bash -c 'mv "${1}" "240-$(stat -c %y ${1}).ts"' \;
In bash if all your files are in a single directory, you don't need to use find at all. You can do a for loop:
for file in 240-*; do
hr_timestamp=$(date -d $(echo "$file" | sed 's/.*-\([0-9]*\)\.ts/\1/'))
mv "$file" "240-$hr_timestamp.ts"
done

Find multiple files and rename them in Linux

I am having files like a_dbg.txt, b_dbg.txt ... in a Suse 10 system. I want to write a bash shell script which should rename these files by removing "_dbg" from them.
Google suggested me to use rename command. So I executed the command rename _dbg.txt .txt *dbg* on the CURRENT_FOLDER
My actual CURRENT_FOLDER contains the below files.
CURRENT_FOLDER/a_dbg.txt
CURRENT_FOLDER/b_dbg.txt
CURRENT_FOLDER/XX/c_dbg.txt
CURRENT_FOLDER/YY/d_dbg.txt
After executing the rename command,
CURRENT_FOLDER/a.txt
CURRENT_FOLDER/b.txt
CURRENT_FOLDER/XX/c_dbg.txt
CURRENT_FOLDER/YY/d_dbg.txt
Its not doing recursively, how to make this command to rename files in all subdirectories. Like XX and YY I will be having so many subdirectories which name is unpredictable. And also my CURRENT_FOLDER will be having some other files also.
You can use find to find all matching files recursively:
find . -iname "*dbg*" -exec rename _dbg.txt .txt '{}' \;
EDIT: what the '{}' and \; are?
The -exec argument makes find execute rename for every matching file found. '{}' will be replaced with the path name of the file. The last token, \; is there only to mark the end of the exec expression.
All that is described nicely in the man page for find:
-exec utility [argument ...] ;
True if the program named utility returns a zero value as its
exit status. Optional arguments may be passed to the utility.
The expression must be terminated by a semicolon (``;''). If you
invoke find from a shell you may need to quote the semicolon if
the shell would otherwise treat it as a control operator. If the
string ``{}'' appears anywhere in the utility name or the argu-
ments it is replaced by the pathname of the current file.
Utility will be executed from the directory from which find was
executed. Utility and arguments are not subject to the further
expansion of shell patterns and constructs.
For renaming recursively I use the following commands:
find -iname \*.* | rename -v "s/ /-/g"
small script i wrote to replace all files with .txt extension to .cpp extension under /tmp and sub directories recursively
#!/bin/bash
for file in $(find /tmp -name '*.txt')
do
mv $file $(echo "$file" | sed -r 's|.txt|.cpp|g')
done
with bash:
shopt -s globstar nullglob
rename _dbg.txt .txt **/*dbg*
find -execdir rename also works for non-suffix replacements on basenames
https://stackoverflow.com/a/16541670/895245 works directly only for suffixes, but this will work for arbitrary regex replacements on basenames:
PATH=/usr/bin find . -depth -execdir rename 's/_dbg.txt$/_.txt' '{}' \;
or to affect files only:
PATH=/usr/bin find . -type f -execdir rename 's/_dbg.txt$/_.txt' '{}' \;
-execdir first cds into the directory before executing only on the basename.
Tested on Ubuntu 20.04, find 4.7.0, rename 1.10.
Convenient and safer helper for it
find-rename-regex() (
set -eu
find_and_replace="$1"
PATH="$(echo "$PATH" | sed -E 's/(^|:)[^\/][^:]*//g')" \
find . -depth -execdir rename "${2:--n}" "s/${find_and_replace}" '{}' \;
)
GitHub upstream.
Sample usage to replace spaces ' ' with hyphens '-'.
Dry run that shows what would be renamed to what without actually doing it:
find-rename-regex ' /-/g'
Do the replace:
find-rename-regex ' /-/g' -v
Command explanation
The awesome -execdir option does a cd into the directory before executing the rename command, unlike -exec.
-depth ensure that the renaming happens first on children, and then on parents, to prevent potential problems with missing parent directories.
-execdir is required because rename does not play well with non-basename input paths, e.g. the following fails:
rename 's/findme/replaceme/g' acc/acc
The PATH hacking is required because -execdir has one very annoying drawback: find is extremely opinionated and refuses to do anything with -execdir if you have any relative paths in your PATH environment variable, e.g. ./node_modules/.bin, failing with:
find: The relative path ‘./node_modules/.bin’ is included in the PATH environment variable, which is insecure in combination with the -execdir action of find. Please remove that entry from $PATH
See also: https://askubuntu.com/questions/621132/why-using-the-execdir-action-is-insecure-for-directory-which-is-in-the-path/1109378#1109378
-execdir is a GNU find extension to POSIX. rename is Perl based and comes from the rename package.
Rename lookahead workaround
If your input paths don't come from find, or if you've had enough of the relative path annoyance, we can use some Perl lookahead to safely rename directories as in:
git ls-files | sort -r | xargs rename 's/findme(?!.*\/)\/?$/replaceme/g' '{}'
I haven't found a convenient analogue for -execdir with xargs: https://superuser.com/questions/893890/xargs-change-working-directory-to-file-path-before-executing/915686
The sort -r is required to ensure that files come after their respective directories, since longer paths come after shorter ones with the same prefix.
Tested in Ubuntu 18.10.
Script above can be written in one line:
find /tmp -name "*.txt" -exec bash -c 'mv $0 $(echo "$0" | sed -r \"s|.txt|.cpp|g\")' '{}' \;
If you just want to rename and don't mind using an external tool, then you can use rnm. The command would be:
#on current folder
rnm -dp -1 -fo -ssf '_dbg' -rs '/_dbg//' *
-dp -1 will make it recursive to all subdirectories.
-fo implies file only mode.
-ssf '_dbg' searches for files with _dbg in the filename.
-rs '/_dbg//' replaces _dbg with empty string.
You can run the above command with the path of the CURRENT_FOLDER too:
rnm -dp -1 -fo -ssf '_dbg' -rs '/_dbg//' /path/to/the/directory
You can use this below.
rename --no-act 's/\.html$/\.php/' *.html */*.html
This command worked for me. Remember first to install the perl rename package:
find -iname \*.* | grep oldname | rename -v "s/oldname/newname/g
To expand on the excellent answer #CiroSantilliПутлерКапут六四事 : do not match files in the find that we don't have to rename.
I have found this to improve performance significantly on Cygwin.
Please feel free to correct my ineffective bash coding.
FIND_STRING="ZZZZ"
REPLACE_STRING="YYYY"
FIND_PARAMS="-type d"
find-rename-regex() (
set -eu
find_and_replace="${1}/${2}/g"
echo "${find_and_replace}"
find_params="${3}"
mode="${4}"
if [ "${mode}" = 'real' ]; then
PATH="$(echo "$PATH" | sed -E 's/(^|:)[^\/][^:]*//g')" \
find . -depth -name "*${1}*" ${find_params} -execdir rename -v "s/${find_and_replace}" '{}' \;
elif [ "${mode}" = 'dryrun' ]; then
echo "${mode}"
PATH="$(echo "$PATH" | sed -E 's/(^|:)[^\/][^:]*//g')" \
find . -depth -name "*${1}*" ${find_params} -execdir rename -n "s/${find_and_replace}" '{}' \;
fi
)
find-rename-regex "${FIND_STRING}" "${REPLACE_STRING}" "${FIND_PARAMS}" "dryrun"
# find-rename-regex "${FIND_STRING}" "${REPLACE_STRING}" "${FIND_PARAMS}" "real"
In case anyone is comfortable with fd and rnr, the command is:
fd -t f -x rnr '_dbg.txt' '.txt'
rnr only command is:
rnr -f -r '_dbg.txt' '.txt' *
rnr has the benefit of being able to undo the command.
On Ubuntu (after installing rename), this simpler solution worked the best for me. This replaces space with underscore, but can be modified as needed.
find . -depth | rename -d -v -n "s/ /_/g"
The -depth flag is telling find to traverse the depth of a directory first, which is good because I want to rename the leaf nodes first.
The -d flag on rename tells it to only rename the filename component of the path. I don't know how general the behavior is but on my installation (Ubuntu 20.04), it could be the file or the directory as long as it is the leaf node of the path.
I recommend the -n (no action) flag first along with -v, so you can see what would get renamed and how.
Using the two flags together, it renames all the files in a directory first and then the directory itself. Working backwards. Which is exactly what I needed.
classic solution:
for f in $(find . -name "*dbg*"); do mv $f $(echo $f | sed 's/_dbg//'); done

Why does find -exec mv {} ./target/ + not work?

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 +.

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