Count number of specific file type of a directory and its sub dir in mac

Question

I use ls -l *.filetype | wc -l but it can only find files in current directory.
How can I also count all files with specific extension in its sub dirs?
Thank you very much.

Answer 1

You can do that with find command:

find . -name "*.filetype" | wc -l

Answer 2

The following compound command, albeit somewhat verbose, guarantees an accurate count because it handles filenames that contain newlines correctly:

total=0; while read -rd ''; do ((total++)); done < <(find . -name "*.filetype" -print0) && echo "$total"

Note: Before running the aforementioned compound command:

1. Firstly, cd to the directory that you want to count all files with specific extension in.
2. Change the filetype part as appropriate, e.g. txt

---

Demo:

To further demonstrate why piping the results of find to wc -l may produce incorrect results:

1. Run the following compound command to quickly create some test files:

   mkdir -p ~/Desktop/test/{1..2} && touch ~/Desktop/test/{1..2}/a-file.txt && touch ~/Desktop/test/{1..2}/$'b\n-file.txt'
   

   This produces the following directory structure on your "Desktop":

   test
   ├── 1
   │   ├── a-file.txt
   │   └── b\n-file.txt
   └── 2
       ├── a-file.txt
       └── b\n-file.txt
   

   _{Note: It contains a total of four .txt files. Two of which have multi-line filenames, i.e. b\n-file.txt}.

   _{On newer version of macOS the files named b\n-file.txt will appear as b?-file.txt in the "Finder", i.e. A question mark indicates the newline in a multi-line filename}

2. Then run the following command that pipes the results of find to wc -l:

   find ~/Desktop/test -name "*.txt" | wc -l
   

   It incorrectly reports/prints:

   6

3. Then run the following suggested compound command:

   total=0; while read -rd ''; do ((total++)); done < <(find ~/Desktop/test -name "*.txt" -print0) && echo "$total"
   

   It correctly reports/prints:

   4