Is there a more succinct alternative to piping to wc for counting files in a directory

Question

If I do ls -1 target_dir | wc -l, I get a count of files in a directory. I find this a bit cumbersome. Is there a more elegant or succinct way?

Answer 1

Assuming bash 4+ (which any supported version of Ubuntu has):

num_files() (
    shopt -s nullglob
    cd -P -- "${1-.}" || return
    set -- *
    echo "$#"
)

Call it as num_files [dir]. dir is optional, otherwise it uses the current directory. Your original version does not count hidden files, so neither does this. If you want that, shopt -s dotglob before set -- *.

Your original example counts not only regular files, but also directories and other devices -- if you really only want regular files (including symlinks to regular files), you will need to check them:

num_files() (
    local count=0

    shopt -s nullglob
    cd -P -- "${1-.}" || return
    for file in *; do
        [[ -f $file ]] && let count++
    done
    echo "$count"
)

If you have GNU find, something like this is also an option (note that this includes hidden files, which your original command did not do):

num_files() {
    find "${1-.}" -maxdepth 1 -type f -printf x | wc -c
}

(change -type to -xtype if you also want to count symlinks to regular files).

Answer 2

f=(target_dir/*);echo ${#f[*]}

works correctly for file with spaces, newlines, etc. in the name.

Answer 3

ls is multi-columns only if it outputs directly to a terminal, you can remove the "-1" option, You can remove the wc "-l" option, only read the first value (lazy solution, not to be used for legual evidences, criminal investigations, mission critical, tactical ops..).

ls target | wc 

Answer 4

If it's succinctness you're after (rather than exact correctness when dealing with files with newlines in their names, etc.), I recommend just aliasing wc -l to lc ("line count"):

$ alias lc='wc -l'
$ ls target_dir|lc

As others have noted, you don't need the -1 option to ls, since it's automatic when ls is writing to a pipe. (Unless you have ls aliased to always use column mode. I've seen that before, but not very often.)

An lc alias is quite handy in general, and for this question, if you look at the "count the current directory" case, ls|lc is about as succinct as you can get.

Answer 5

So far Aaron's is the only approach more succinct than your own. A more correct version of your approach might look like:

ls -aR1q | grep -Ecv '^\./|/$|^$'

That recursively lists all files - not directories - one per line including .dotfiles beneath the current directory using shell globs as necessary to replace non-printable characters. grep filters out any parent directory listings or .. or */ or blank lines - so there should only be one line per file - the total count of which grep returns to you. If you want child directories included as well do:

ls -aR1q | grep -Ecv '^\.{1,2}/|^$'

Remove the -R in either case if you do not want recursive results.