Using find command to grab the file extensions in directory in shell script [duplicate] - linux

This question already has answers here:
How can I find all of the distinct file extensions in a folder hierarchy?
(17 answers)
Closed 1 year ago.
So far I have tried
extension=$(find /home/path-to-dir -type f -name '*.*' | sed 's/^.*\.//' | sort -u)
It is giving me extension right after . but it is failing for text.data.json ( I only need json)
similar example stack/~.hello.py ( I only need py)
also I m trying to find the creation date of a file ? is it possible ?

As an alternative to the sed command, we can use parameter expansion to get the string after the last .;
find /home/path-to-dir -type f -name '*.*' -exec bash -c 'echo ${0##*.}' {} \;
Small example:
--> ls
ahahha~bla.py bla.bla.json ok.py test.json text.data.json
-->
-->
--> find . -type f -name '*.*' -exec bash -c 'echo ${0##*.}' {} \; | sort -u
json
py
Extract filename and extension in Bash

Using this i solved it
find . -type f -name "[^.]*.*" -exec bash -c 'printf "%s\000" "${###*.}"' argv0 '{}' + | sort -uz | tr '\0' '\n'

Related

Linux find command get all text in the file and print file path

I need to get all the texts in the matching file in the folder. However, at the same time need to get the matching file path as well. How can I get the matching file path as well using the following command.
find . -type f -name release.txt | xargs cat
try
find . -type f -name release.txt -exec grep -il {} \; | xargs cat
Skip xargs, just do:
find . -type f -name release.txt -exec sh -c 'echo "$1"; cat "$1"' _ {} \;

How to use 'cat' command with -exec in bash? [duplicate]

This question already has answers here:
How to move or copy files listed by 'find' command in unix?
(5 answers)
Redirecting stdout with find -exec and without creating new shell
(3 answers)
Closed 4 years ago.
I search for some files and I want to replace old content with new content from other files, so I have
#!/bin/bash
find /home/old -path "*$1" -exec cat /home/new/$1 > {} \;
When I execut:
> sh find.sh 'blam.php'
Problem is the script is creating a file called {} in the same dir with find.sh
The problem you get is that > is part of shell syntax, and should be literal for find command and syntactic in exec command.
what you are trying to do may be done in two steps
generating script
executing the script
.
find /home/old -path "*$1" -printf 'cat /home/new/'"$1"' > %p\n' > script.sh
sh script.sh
this way allows to check the commands, or using pipe
find /home/old -path "*$1" -printf 'cat /home/new/'"$1"' > %p\n' | sh
another way less efficient because spwans a shell for each file
find /home/old -path "*$1" -exec sh -c 'cat "/home/new/$1" > {}' _ "$1" \;
The problem here is that > {} is not part of the find command. The script is first interpreted by the shell, and the meaning of > is handled by the shell before passing the stuff around it as arguments to execute:
$ set -- blam.php
$ set -x
$ find /home/old -path "*$1" -exec cat "/home/new/$1" > {} \;
+ find /home/old -path '*blam.php' -exec cat /home/new/blam.php ';'
If you want a copy of your file somewhere else, use cp.

Using 'find' to return filenames without extension

I have a directory (with subdirectories), of which I want to find all files that have a ".ipynb" extension. But I want the 'find' command to just return me these filenames without the extension.
I know the first part:
find . -type f -iname "*.ipynb" -print
But how do I then get the names without the "ipynb" extension?
Any replies greatly appreciated...
To return only filenames without the extension, try:
find . -type f -iname "*.ipynb" -execdir sh -c 'printf "%s\n" "${0%.*}"' {} ';'
or (omitting -type f from now on):
find "$PWD" -iname "*.ipynb" -execdir basename {} .ipynb ';'
or:
find . -iname "*.ipynb" -exec basename {} .ipynb ';'
or:
find . -iname "*.ipynb" | sed "s/.*\///; s/\.ipynb//"
however invoking basename on each file can be inefficient, so #CharlesDuffy suggestion is:
find . -iname '*.ipynb' -exec bash -c 'printf "%s\n" "${#%.*}"' _ {} +
or:
find . -iname '*.ipynb' -execdir basename -s '.sh' {} +
Using + means that we're passing multiple files to each bash instance, so if the whole list fits into a single command line, we call bash only once.
To print full path and filename (without extension) in the same line, try:
find . -iname "*.ipynb" -exec sh -c 'printf "%s\n" "${0%.*}"' {} ';'
or:
find "$PWD" -iname "*.ipynb" -print | grep -o "[^\.]\+"
To print full path and filename on separate lines:
find "$PWD" -iname "*.ipynb" -exec dirname "{}" ';' -exec basename "{}" .ipynb ';'
Here's a simple solution:
find . -type f -iname "*.ipynb" | sed 's/\.ipynb$//1'
I found this in a bash oneliner that simplifies the process without using find
for n in *.ipynb; do echo "${n%.ipynb}"; done
If you need to have the name with directory but without the extension :
find . -type f -iname "*.ipynb" -exec sh -c 'f=$(basename $1 .ipynb);d=$(dirname $1);echo "$d/$f"' sh {} \;
find . -type f -iname "*.ipynb" | grep -oP '.*(?=[.])'
The -o flag outputs only the matched part. The -P flag matches according to Perl regular expressions. This is necessary to make the lookahead (?=[.]) work.
Perl One Liner
what you want
find . | perl -a -F/ -lne 'print $F[-1] if /.*.ipynb/g'
Then not your code
what you do not want
find . | perl -a -F/ -lne 'print $F[-1] if !/.*.ipynb/g'
NOTE
In Perl you need to put extra .. So your pattern would be .*.ipynb
If there's no occurrence of this ".ipynb" string on any file name other than a suffix, then you can try this simpler way using tr:
find . -type f -iname "*.ipynb" -print | tr -d ".ipbyn"
If you don't know that the extension is or there are multiple you could use this:
find . -type f -exec basename {} \;|perl -pe 's/(.*)\..*$/$1/;s{^.*/}{}'
and for a list of files with no duplicates (originally differing in path or extension)
find . -type f -exec basename {} \;|perl -pe 's/(.*)\..*$/$1/;s{^.*/}{}'|sort|uniq
Another easy way which uses basename is:
find . -type f -iname '*.ipynb' -exec basename -s '.ipynb' {} +
Using + will reduce the number of invocations of the command (manpage):
-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, and (when find is being
invoked from a shell) it should be quoted (for example, '{}')
to protect it from interpretation by shells. The command is
executed in the starting directory. If any invocation with
the `+' form returns a non-zero value as exit status, then
find returns a non-zero exit status. If find encounters an
error, this can sometimes cause an immediate exit, so some
pending commands may not be run at all. For this reason -exec
my-command ... {} + -quit may not result in my-command
actually being run. This variant of -exec always returns
true.
Using -s with basename runs accepts multiple filenames and removes a specified suffix (manpage):
-a, --multiple
support multiple arguments and treat each as a NAME
-s, --suffix=SUFFIX
remove a trailing SUFFIX; implies -a

How to convert some files from dos format to unix

I know how to change file format from dos to unix by use dos2unix, but how can I change ALL the files will under a directory tree. Can dos2unix change files recursively?
for example, I have some files like following:
TOPDIR
|
+-----dir1
| |
| +---file1,file2, file3
|
+-----dir2
|
+---file4,file5
How can I change them in one time, or use some shell scripts?
better to do find /path -type -f -exec dos2unix '{}' \;
find /path -name '*' -type f -exec dos2unix {} \;
dos2unix -k `find . -type f`
find . -type f -exec dos2unix -k '{}' \;
find . -type f -print | xargs dos2unix -k
Any of above command can be used from TOPDIR

How to only get file name with Linux 'find'?

I'm using find to all files in directory, so I get a list of paths. However, I need only file names. i.e. I get ./dir1/dir2/file.txt and I want to get file.txt
In GNU find you can use -printf parameter for that, e.g.:
find /dir1 -type f -printf "%f\n"
If your find doesn't have a -printf option you can also use basename:
find ./dir1 -type f -exec basename {} \;
Use -execdir which automatically holds the current file in {}, for example:
find . -type f -execdir echo '{}' ';'
You can also use $PWD instead of . (on some systems it won't produce an extra dot in the front).
If you still got an extra dot, alternatively you can run:
find . -type f -execdir basename '{}' ';'
-execdir utility [argument ...] ;
The -execdir primary is identical to the -exec primary with the exception that utility will be executed from the directory that holds the current file.
When used + instead of ;, then {} is replaced with as many pathnames as possible for each invocation of utility. In other words, it'll print all filenames in one line.
If you are using GNU find
find . -type f -printf "%f\n"
Or you can use a programming language such as Ruby(1.9+)
$ ruby -e 'Dir["**/*"].each{|x| puts File.basename(x)}'
If you fancy a bash (at least 4) solution
shopt -s globstar
for file in **; do echo ${file##*/}; done
If you want to run some action against the filename only, using basename can be tough.
For example this:
find ~/clang+llvm-3.3/bin/ -type f -exec echo basename {} \;
will just echo basename /my/found/path. Not what we want if we want to execute on the filename.
But you can then xargs the output. for example to kill the files in a dir based on names in another dir:
cd dirIwantToRMin;
find ~/clang+llvm-3.3/bin/ -type f -exec basename {} \; | xargs rm
On mac (BSD find) use:
find /dir1 -type f -exec basename {} \;
As others have pointed out, you can combine find and basename, but by default the basename program will only operate on one path at a time, so the executable will have to be launched once for each path (using either find ... -exec or find ... | xargs -n 1), which may potentially be slow.
If you use the -a option on basename, then it can accept multiple filenames in a single invocation, which means that you can then use xargs without the -n 1, to group the paths together into a far smaller number of invocations of basename, which should be more efficient.
Example:
find /dir1 -type f -print0 | xargs -0 basename -a
Here I've included the -print0 and -0 (which should be used together), in order to cope with any whitespace inside the names of files and directories.
Here is a timing comparison, between the xargs basename -a and xargs -n1 basename versions. (For sake of a like-with-like comparison, the timings reported here are after an initial dummy run, so that they are both done after the file metadata has already been copied to I/O cache.) I have piped the output to cksum in both cases, just to demonstrate that the output is independent of the method used.
$ time sh -c 'find /usr/lib -type f -print0 | xargs -0 basename -a | cksum'
2532163462 546663
real 0m0.063s
user 0m0.058s
sys 0m0.040s
$ time sh -c 'find /usr/lib -type f -print0 | xargs -0 -n 1 basename | cksum'
2532163462 546663
real 0m14.504s
user 0m12.474s
sys 0m3.109s
As you can see, it really is substantially faster to avoid launching basename every time.
Honestly basename and dirname solutions are easier, but you can also check this out :
find . -type f | grep -oP "[^/]*$"
or
find . -type f | rev | cut -d '/' -f1 | rev
or
find . -type f | sed "s/.*\///"
-exec and -execdir are slow, xargs is king.
$ alias f='time find /Applications -name "*.app" -type d -maxdepth 5'; \
f -exec basename {} \; | wc -l; \
f -execdir echo {} \; | wc -l; \
f -print0 | xargs -0 -n1 basename | wc -l; \
f -print0 | xargs -0 -n1 -P 8 basename | wc -l; \
f -print0 | xargs -0 basename | wc -l
139
0m01.17s real 0m00.20s user 0m00.93s system
139
0m01.16s real 0m00.20s user 0m00.92s system
139
0m01.05s real 0m00.17s user 0m00.85s system
139
0m00.93s real 0m00.17s user 0m00.85s system
139
0m00.88s real 0m00.12s user 0m00.75s system
xargs's parallelism also helps.
Funnily enough i cannot explain the last case of xargs without -n1.
It gives the correct result and it's the fastest ¯\_(ツ)_/¯
(basename takes only 1 path argument but xargs will send them all (actually 5000) without -n1. does not work on linux and openbsd, only macOS...)
Some bigger numbers from a linux system to see how -execdir helps, but still much slower than a parallel xargs:
$ alias f='time find /usr/ -maxdepth 5 -type d'
$ f -exec basename {} \; | wc -l; \
f -execdir echo {} \; | wc -l; \
f -print0 | xargs -0 -n1 basename | wc -l; \
f -print0 | xargs -0 -n1 -P 8 basename | wc -l
2358
3.63s real 0.10s user 0.41s system
2358
1.53s real 0.05s user 0.31s system
2358
1.30s real 0.03s user 0.21s system
2358
0.41s real 0.03s user 0.25s system
I've found a solution (on makandracards page), that gives just the newest file name:
ls -1tr * | tail -1
(thanks goes to Arne Hartherz)
I used it for cp:
cp $(ls -1tr * | tail -1) /tmp/

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