Pretty much I want to cd to the output of the find command:
find ~ -name work_project_linux
cd the_output
In general the best way to execute an arbitrary command on the results of find is with find -exec. Curly braces {} are placeholders for the file names it finds, and the entire command ends with + or \;. For example, this will run ls -l on all of the files found:
find ~ -name work_project_linux -exec ls -l {} +
It doesn't work with some special commands like cd, though. -exec runs binaries, such as those found in /usr/bin, and cd isn't a binary. It's a shell builtin, a special type of command that the shell executes directly instead of calling out to some executable on disk. For shell builtins you can use command substitution:
cd "$(find ~ -name work_project_linux)"
This wouldn't work if find finds multiple files. It's only good for a single file name. Command substitution also won't handle some unusual file names correctly, such as those with embedded newlines—unusual, but legal.
Related
I would like to find txt files with find command and move the directory of the found file, and then apply a command to the file using a bash shell one-liner
For example, this command works, but the acmd is executed in the current directory.
$ find . -name "*.txt" | xargs acmd
I would like to run acmd in the txt file's direcotry.
Does anyone have good idea?
From the find man page:--
-execdir command ;
-execdir command {} +
Like -exec, but the specified command is run from the subdirec‐
tory containing the matched file, which is not normally the
directory in which you started find. This a much more secure
method for invoking commands, as it avoids race conditions dur‐
ing resolution of the paths to the matched files. As with the
-exec action, the `+' form of -execdir will build a command line
to process more than one matched file, but any given invocation
of command will only list files that exist in the same subdirec‐
tory. If you use this option, you must ensure that your $PATH
environment variable does not reference `.'; otherwise, an
attacker can run any commands they like by leaving an appropri‐
ately-named file in a directory in which you will run -execdir.
The same applies to having entries in $PATH which are empty or
which are not absolute directory names. If find encounters an
error, this can sometimes cause an immediate exit, so some pend‐
ing commands may not be run at all. The result of the action
depends on whether the + or the ; variant is being used;
-execdir command {} + always returns true, while -execdir com‐
mand {} ; returns true only if command returns 0.
Just for completeness, the other option would be to do:
$ find . -name \*.txt | xargs -i sh -c 'echo "for file $(basename {}), the directory is $(dirname '{}')"'
for file schedutil.txt, the directory is ./Documentation/scheduler
for file devices.txt, the directory is ./Documentation/admin-guide
for file kernel-parameters.txt, the directory is ./Documentation/admin-guide
for file gdbmacros.txt, the directory is ./Documentation/admin-guide/kdump
...
i.e. have xargs "defer to a shell". In usecases where -execdir suffices, go for it.
Apreciate any help and excuse me if my terminology is incorrect.
What I am trying to do is write a scrpit/.bat file that will do the following:
copy 1 directory(and subdirectories) from pointA, to point B.
Then in pointB(and subdirectories) unzip the files which will give *.csv files
Then in pointB(and subdirectories) I want to delete some rows from all these csv files
This unix command, run on cygwin, will copy all the files from /cygdrive/v/pointA/* to the current directory . (i.e. the dot is the current working directory)
cp /cygdrive/v/pointA/* .
This unix command, run on cygwin, will go through all the files in the directory and subdirectories that end with .zip
and unzip them
find -iname *.zip -execdir unzip {} \;
This unix command, run on cygwin, will go through all the files in the directory and subdirectories that end with .csv
For each file it deletes the 1st 6 rows and the last row and that's the returned file.
find ./ -iname '*.csv' -exec sed -i '1,6d;$ d' '{}' ';'
I was looking to do this in one script/bat file but I am having trouble with the first find command
I am having trouble with the find and unzip commands on the one line and am wondering how and if this can be done
chdir C:\pointA
C:\cygwin\bin\cp.exe /cygdrive/v/pointB/* .
::find -iname *.zip -execdir unzip {} \;
::find ./ -iname '*.csv' -exec sed -i '1,6d;$ d' '{}' ';'
I did try something like this:
C:\cygwin\bin\find.exe -iname *.zip -execdir C:\cygwin\bin\unzip.exe {} \;
but I get the following:
/usr/bin/find: missing argument to `-execdir'
Can anyone advise if/how this can be done?
The Cygwin tools use their own kind of paths, e.g. /cygdrive/c/cygwin/bin/unzip.exe though sometimes the Windows paths with backslashes work, the backslashes do tend to confuse the Cygwin tools.
I highly recommend you write your tool in Bash shell script instead of a cmd.exe Windows batch file. In my experience (1) it's much easier to do flow control in bash scripts than in batch files, and (2) the Cygwin environment works better from Bash. You can open a bash shell and run bash yourscript.sh.
Your Bash script might look something like this: (untested)
#!/bin/bash
# This script would be run from a Cygwin Bash shell.
# You can use the Mintty program or run C:\cygwin\bin\bash --login
# to start a bash shell from Windows Command Prompt.
# Configure bash so the script will exit if a command fails.
set -e
cd /cygdrive/c/pointA
cp /cygdrive/v/pointB/* .
# I did try something like this:
# 1. Make sure you quote wildcards so the shell doesn't expand them
# before passing them to the 'find' program.
#
# 2. If you start bash with the --login option, the PATH will be
# configured so that C:\cygwin\bin is in your PATH, and you can
# just call 'find', 'cp' etc. without specifying full path to it.
# This will unzip all .zip files in all subdirectories under this one.
find -iname '*.zip' -execdir unzip {} \;
What is the difference between these two commands in the command line in the terminal on ubuntu?
find . -name "*.txt"
find . -name *.txt
It depends on the shell you are using and the contents of your directory.
If you're unfortunate enough to use csh (or some of its heritage, like zsh) for some reason, it will refuse to execute this when there is no file in your directory that matches the pattern (unless you've turned that behaviour off).
If there are files that match the pattern, the command will be expanded by the shell:
find . -name foo.txt bar.txt baz.txt
and find will report a syntax error. Unless there is a single file that matches, then you get:
find . -name foo.txt
and this will then only find files named "foo.txt" in subdirectories.
Only if you're using a sane shell and there are no files matching in the current directory will the two commands be identical.
Moral: don't do it. Always use quotes.
I need to write a shell script for finding the mode of the files and the code needs to be able to accept other Unix commands as optional arguments.
for example:
mycode 644 ls -l
should perform the command ls -l on all files in the current directory that have mode 644.
I only need to know what aspects of shell scripting help me here to run the ls -l.
I think for you the best will be to use find.
So for example the operation you are looking for can be executed by this simple comand:
find . -perm 0644 -exec ls -l {} \;
Your script may look like:
#!/bin/sh
perm=$1
shift
find . -perm $perm $* {} \;
The following will do it:
#!/bin/bash
mode=$1
shift
$*
It removes the first parameter into a variable, and executes the rest as a single shell command. It doesn't attempt to handle mode, but you indicated that your question wasn't about that.
I'm writing a deploy script, and I need to run a less compiler against all .less files in a directory. This is easy to do with the following find command:
find -name "*.less" -exec plessc {} {}.css \;
After running this command on a folder with a file named main.less, I'm left with a file named main.less.css, but I want it to be main.css.
I know I can easily strip the .less portion of the resulting files with this command: rename 's/\.less//' *.css but I'm hoping to learn something new about using -exec.
Is it possible to modify the name of the file that matches while using it in the -exec parameter?
Thanks!
Your find command is using a couple of non standard GNU extensions:
You do not state where to find, this is an error in POSIX but GNU find select the current directory in that case
You use a non isolated {}, POSIX find doesn't expand it in that case.
Here is a one liner that should work with most find implementations and fix your double extension issue:
find . -name "*.less" -exec sh -c "plessc \$0 \$(dirname \$0)/\$(basename \$0 less)css" {} \;
On Solaris 10 and older, sh -c should be replaced by ksh -c if the PATH isn't POSIX compliant.
No, it is not possible to do it directly. You can only use {} to directly insert the full filename. However, in exec, you COULD put in other things like awk. Or you can redirect output to another program via pipes.
From the find man 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.