Another shell script to share

At home I get a lot of use out of the tree command line utility. It gives me a quick and easy way to look at a nested directory structure without having to leave the command line. The computers at work don't have the tree utility, and every so often I really miss it.

So, I wrote my own.

Here's a bash script that is a simplified version of the tree utility.

#!/bin/bash

tree() {
    local prefix=$1
    local dir=$2
    local count=`ls -l $dir | wc -l`
 
    if [[ $count -eq 0 ]]
    then
        return
    fi
 
    local i=1
    local bar="|"
    local nextPrefix="|   "
 
    for file in "$dir"/*
    do
        i=$(($i + 1))
        if [[ $i -eq $count ]]
        then
            bar="\`"
            nextPrefix="    "
        fi
        filename=$(basename $file)
        echo "$prefix$bar---$filename"
        if [[ -d $file ]]
        then
            tree "$prefix$nextPrefix" $file
        fi
    done
}


if [[ -z $1 ]]
then
    dir=`pwd`
else
    dir=$1
fi

if [[ ! -e $dir ]]
then
    echo "Directory $dir does not exist"
    exit 1
elif [[ ! -d $dir ]]
then
    echo "$dir is not a directory"
    exit 2
fi

basename $dir
tree "" $dir