On a Linux machine I would like to traverse a folder hierarchy and get a list of all of the distinct file extensions within it.
What would be the best way to achieve this from a shell?
On a Linux machine I would like to traverse a folder hierarchy and get a list of all of the distinct file extensions within it.
What would be the best way to achieve this from a shell?
Try this (not sure if it's the best way, but it works):
find . -type f | perl -ne 'print $1 if m/\.([^.\/]+)$/' | sort -u
It work as following:
No need for the pipe to sort
, awk can do it all:
find . -type f | awk -F. '!a[$NF]++{print $NF}'
Recursive version:
find . -type f | sed -e 's/.*\.//' | sed -e 's/.*\///' | sort -u
If you want totals (how may times the extension was seen):
find . -type f | sed -e 's/.*\.//' | sed -e 's/.*\///' | sort | uniq -c | sort -rn
Non-recursive (single folder):
for f in *.*; do printf "%s\n" "${f##*.}"; done | sort -u
I've based this upon this forum post, credit should go there.
Powershell:
dir -recurse | select-object extension -unique
Thanks to http://kevin-berridge.blogspot.com/2007/11/windows-powershell.html
Find everythin with a dot and show only the suffix.
find . -type f -name "*.*" | awk -F. '{print $NF}' | sort -u
if you know all suffix have 3 characters then
find . -type f -name "*.???" | awk -F. '{print $NF}' | sort -u
or with sed shows all suffixes with one to four characters. Change {1,4} to the range of characters you are expecting in the suffix.
find . -type f | sed -n 's/.*\.\(.\{1,4\}\)$/\1/p'| sort -u
Adding my own variation to the mix. I think it's the simplest of the lot and can be useful when efficiency is not a big concern.
find . -type f | grep -o -E '\.[^\.]+$' | sort -u
I tried a bunch of the answers here, even the "best" answer. They all came up short of what I specifically was after. So besides the past 12 hours of sitting in regex code for multiple programs and reading and testing these answers this is what I came up with which works EXACTLY like I want.
find . -type f -name "*.*" | grep -o -E "\.[^\.]+$" | grep -o -E "[[:alpha:]]{2,16}" | awk '{print tolower($0)}' | sort -u
If you need a count of the file extensions then use the below code
find . -type f -name "*.*" | grep -o -E "\.[^\.]+$" | grep -o -E "[[:alpha:]]{2,16}" | awk '{print tolower($0)}' | sort | uniq -c | sort -rn
While these methods will take some time to complete and probably aren't the the best ways to go about the problem, they work.
Update: Per @alpha_989 long file extensions will cause an issue. That's due to the original regex "[[:alpha:]]{3,6}". I have updated the answer to include the regex "[[:alpha:]]{2,16}". However anyone using this code should be aware that those numbers are the min and max of how long the extension is allowed for the final output. Anything outside that range will be split into multiple lines in the output.
Note: Original post did read "- Greps for file extensions between 3 and 6 characters (just adjust the numbers if they don't fit your need). This helps avoid cache files and system files (system file bit is to search jail)."
Idea: Could be used to find file extensions over a specific length via:
find . -type f -name "*.*" | grep -o -E "\.[^\.]+$" | grep -o -E "[[:alpha:]]{4,}" | awk '{print tolower($0)}' | sort -u
Where 4 is the file extensions length to include and then find also any extensions beyond that length.
In Python using generators for very large directories, including blank extensions, and getting the number of times each extension shows up:
import json
import collections
import itertools
import os
root = '/home/andres'
files = itertools.chain.from_iterable((
files for _,_,files in os.walk(root)
))
counter = collections.Counter(
(os.path.splitext(file_)[1] for file_ in files)
)
print json.dumps(counter, indent=2)
Since there's already another solution which uses Perl:
If you have Python installed you could also do (from the shell):
python -c "import os;e=set();[[e.add(os.path.splitext(f)[-1]) for f in fn]for _,_,fn in os.walk('/home')];print '\n'.join(e)"
None of the replies so far deal with filenames with newlines properly (except for ChristopheD's, which just came in as I was typing this). The following is not a shell one-liner, but works, and is reasonably fast.
import os, sys
def names(roots):
for root in roots:
for a, b, basenames in os.walk(root):
for basename in basenames:
yield basename
sufs = set(os.path.splitext(x)[1] for x in names(sys.argv[1:]))
for suf in sufs:
if suf:
print suf
I think the most simple & straightforward way is
for f in *.*; do echo "${f##*.}"; done | sort -u
It's modified on ChristopheD's 3rd way.
I don't think this one was mentioned yet:
find . -type f -exec sh -c 'echo "${0##*.}"' {} \; | sort | uniq -c
you could also do this
find . -type f -name "*.php" -exec PATHTOAPP {} +