Find files whose name is 4 characters long [duplicate]

Question

This question already has an answer here:

• How can I search for a file with fixed name length using ls? 4 answers

I would like to find files whose name has only 4 characters.

Example, there are three files under /tmp:

$ ls /tmp
txt
file
linux

Output should only show file because it only has 4 characters.

Answer 1

Use the ? wildcard for file globbing:

ls -d /tmp/????

This will print all files and directories whose filename is 4-char long.

As suggested by @roaima, the -d flag will prevent ls to display the content of subdirectories that match the pattern.

Answer 2

List files in /tmp only:

cd /tmp
find . ! -name . -prune -path './????' -type f

List files in /tmp recursively:

find /tmp -path '*/????' -type f

Answer 3

Try:

find /tmp -type f -print| awk -F/ ' length($NF)  == 4 '

What awk does:

• Using / as field separator,
• Finding filename $NF (last field)
• Computing length
• And check if value is 4, then print it.

Answer 4

This seems to me like the most straightforward way to find a file of four bytes:

find /tmp -type f -size 4c

Edit: to find a file name of four bytes:

find /tmp -type f -name '????'

Answer 5

There's also a perl (5.10 or newer) solution:

perl -E 'say for </tmp/????>;'

A slightly more flexible version where you can specify the desired length:

perl -E 'my $w = "?" x shift; say for </tmp/$w>;' 4

Answer 6

Assuming you're using bash, you can do the following:

shopt -s globstar
shopt -s nullglob
filearray=(/tmp/**/????)

This will put the list of files you want in an array filearray. Newlines (and other exotic characters) in the filename will be handled correctly.

Setting globstar enables ** in glob patterns to match across subdirectories, giving the required recursive search.

Setting nullglob simply causes the expansion to expand to nothing if there are no matches. Otherwise it will expand to itself which is probably not what you want.

Answer 7

"/tmp/" takes 5 characters. That's why there is "9" (5+4) in test

for i in /tmp/* ;
  do [ "${#i}" -eq 9 ] && printf %s\\n "$i";
done

or

for i in /tmp/* ;
  do i="${i#/tmp/}"; # to get rid of /tmp/
  [[ "${#i}" -eq 4 ]] && printf %s\\n "$i"; # there is 4 in test!
done

FWIW. It does not fail on newline (@cuonglm), can be easilly converted to list only 140 character long file names (@don_crissti).

Answer 8

As globbing is done by the shell, there is even no need to call ls or find, echo does the trick:

$ echo /tmp/????
/tmp/file
$

Only thing is, if there is no file whose name is 4 characters long, it will just print

/tmp/????

You might want a one-liner bash script that checks this and also prints one file per line:

pattern=/tmp/????? ; for f in $pattern ; do if [ $f != "$pattern" ] ; then echo $f ; fi ; done

Answer 9

How about:

ls /tmp | grep -e '^.\{4\}$'    

for a grep based answer.