Bash Recursive Function Call on all elements in a directory

Question

First post on StackOverflow, first time using Bash.

I'm currently trying to construct a function to read a file, then give me out put depending on the status:

• If it's a file, then print the name, size and type
• If it's a symbolic link, then print the name and it's target
• If it's a directory, then recursively call the function on each item.
• Otherwise return 'unknown'

I know the code is rough so far, but all I really need help with is the recursive looping part. How do I loop through the contents of a directory using a While Loop?

Here's my code so far:

#!/bin/bash

function fileChecker f  {

    if [-e $1 ]; then
        if [ -f $1]; then 
            SIZE = 'du -k $1 | cut -f1'
            CONTENT = 'file $1 | cut -d':' -f2'
            echo $1 +" " +  $SIZE + " " + $CONTENT
    elif[ -h $1 ]; then
        LINK = get info from $1
        echo $1 + " " + "symbolic link " + $LINK
    elif [ -d $1 ]; then 
        while  [ ???? ]; do  
            fileChecker n
        do
    else
        echo $1 + "unknown"
    fi
fi 
}

Thanks in advance!

Answer 1

There's nothing stopping you to call your function recursively, like this:

fileChecker() {
    # ...
    for f in "$1"/*; do
        fileChecker "$f"
    done
}

Here's your script with a few fixes (*), behaving as described:

#!/bin/bash
fileChecker() {
    if [ -f "$1" ]; then 
        size=$(du -k "$1" | cut -f1)
        content=$(file "$1" | cut -d':' -f2)
        echo "$1 $size $content"
    elif [ -h "$1" ]; then
        link=$(readlink -f "$1")
        echo "$1 symbolic link $link"
    elif [ -d "$1" ]; then 
        for f in "$1"/*; do
            [ -e "$f" ] || [ -h "$f" ] && fileChecker "$f"
        done
    else
        echo "$1 unknown"
    fi
}

(*) Fixes:

• correct spacing before and after [ command
• correct quoting of variables ("$1")
• omitted redundant checking of file existence, since -f already checks if file exists (and is regular)
• using command substitution $(cmd ...) instead of backticks (simpler and more readable)
• string concat fixed in echo
• using readlink -f for symlink target
• POSIX-compliance (function definition)

Just note that for f in "$1"/* will not loop over filenames starting with a dot ("hidden files"). Also note the [ -e "$f" ] || [ -h "$f" ] check before a call to fileChecker to prevent calling it on "$1"/* in case the glob does not expand (when there are no files in dir "$1").