BASH: Writing a Script to Recursively Travel a Directory of N Levels

Question

I have the following directory structure for example:

/test_dir/d
/test_dir/d/cron
/test_dir/d/cache
/test_dir/d/...(more sub dirs)
/test_dir/tree
/test_dir/         


        

Answer 1

Several problems with the script. It should be like this:

#!/bin/bash

#script to recursively travel a dir of n levels

function traverse() {
for file in "$1"/*
do
    if [ ! -d "${file}" ] ; then
        echo "${file} is a file"
    else
        echo "entering recursion with: ${file}"
        traverse "${file}"
    fi
done
}

function main() {
    traverse "$1"
}

main "$1"

However, the correct way to recursively traverse a directory is by using the find command:

find . -print0 | while IFS= read -r -d '' file
do 
    echo "$file"
done

Answer 2

/test_dir/treea is a file
/test_dir/treeb is a file
/test_dir/treec is a file
/test_dir/treed is a file

These are the errors. Some which are not only not directories but do not exist are considered files. I think you need to separate your new files from the directory with slash:

    traverse "${1}/${file}"

And also check that they do exist as well.

Since you're using bash as well, I'd suggest this form instead:

#!/bin/bash

shopt -s dotglob  ## Optionally would allow matches for directories beginning with .
shopt -s nullglob

function traverse {
    local a file
    for a; do
        for file in "$a"/*; do
            if [[ -d $file ]]; then
                traverse "$file"
            else
                echo " $file is a file."
            fi
        done
    done
}

traverse "$@"

You can run the script with multiple arguments.

A fixed version of your script:

#!/bin/bash

#script to recursively travel a dir of n levels

function traverse() {   
    for file in $(ls "$1")
    do
        #current=${1}{$file}
        if [[ ! -d ${1}/${file} ]]; then
            echo " ${1}/${file} is a file"
        else
            #echo "entering recursion with: ${1}${file}"
            traverse "${1}/${file}"
        fi
    done
}

function main() {
    traverse "$1"
}

main "$1"