Iterating over file (and directory) names with bash

Question

I was trying to write a bash script for counting the number of files and the number of directories of the local directory. This was my first try:

#!/bin/bash
fil         


        

Answer 1

Use a wild card: for file in *; do …; done. That keeps the spaces in the names correct. Consider shopt -s nullglob too. Neither your code nor my suggestion lists names starting with a dot ..

Also, use if [ -d "$file" ] with double quotes around the variable value to avoid spacing problems.

Hence:

#!/bin/bash

shopt -s nullglob
files=0
dir=0
for file in *
do
    if [ -d "$file" ]
    then
        dir=$(($dir+1))
    else
        files=$(($files+1))
    fi
done 
echo "files=$files, directories=$dir"

In Bash, there are also other ways of writing the arithmetic, such as ((files++)).

Answer 2

I think that Jonathan Leffler's answer is exactly what you need.

An alternative that shows the power of bash arrays and eliminates the need for loops:

shopt -s nullglob
dirs=(*/)
ndir="${#dirs[@]}"
files=(*)
nfile=$(( "${#files[@]}" - ndir))
echo "files=$nfile, directories=$ndir"

This works as follows:

• dirs=(*/) creates an array of the names of the directories.

• ndir="${#dirs[@]}" counts the number of directories.

• files=(*) creates an array of the names of all files and directories.

• nfile=$(( "${#files[@]}" - ndir)) computes the number of files by taking the number of elements of files and subtracting from that the number of directories.

• echo "files=$nfile, directories=$ndir" prints out the results.

This will only work in a shell, like bash, that supports arrays. On many systems, sh is dash which does not support arrays. So, use bash script when executing this script.