[BASH] Recursion

[wick3dsunny]

Hi guys,

I am trying to write this script in bash which prints the stats of every file in the directory using recursion and stat command but the recursion seems to not work... Any help would be appreciated


#! /usr/bin/env bash

function display(){

if test $# -eq 0; then
directory=`pwd`

elif test $# -eq 1; then
directory=$1

fi

for files in `ls -A $1`
do

echo $directory
cd $directory
stat -c %n,%F,%i,%s $files

if test -d $files; then
echo "{"
display $directory/$files
echo "}"

fi
done

}

display $1

[ghostdog74]

recursion?


# stat -c %n,%F,%i,%s *

if you need to traverse directories, use the find command with options like -exec or -execdir. you do not need to reinvent the wheel.

[Neural oD]

maybe try this: for files in `ls -AR $1`

[wick3dsunny]

I would really love to use the find and ls -R command but I am not allowed to use it unfortunately :(!

I am trying to traverse through directories but getting stuck with recursion. any help with what the problem is ?

[lloyd_b]

Well, one MAJOR problem with your code is that you're never "cd"ing back to the parent directory after recursing into a child directory...

You need to stash the parent directory somewhere, before resetting the value of "directory". Remember, all variables are GLOBAL in a shell script, so it does NOT revert to the previous value of "directory" when the function returns (with the exception of the positional parameters ($1, $2, $#, etc).

Here's some example code. What I've done is declared a variable ("level") to keep track of what recursion level it's at, and then used an array variable ("directory[]") to store the previous directory each time it recurses.

A few notes:
1. I prefer the "if [ ... ]" form of the "test", rather than the longer form you used.
2. I prefer the terser form of the if/for/etc statements, since they use less vertical space.
3. I *strongly* recommend indenting your code for each if/for/etc statement - it makes it a LOT easier to read and understand.


#! /usr/bin/env bash

function display(){

level=$((level + 1))

if [ $# -eq 0 ]; then
directory[$level]=`pwd`
else
directory[$level]=$1
fi

echo "entering directory ${directory[$level]}"
cd "${directory[$level]}"

for files in `ls -A $1`; do
stat -c %n,%F,%i,%s $files

if [ -d $files ]; then
echo "{"
display ${directory[$level]}/$files
echo "}"
fi
done

level=$((level - 1))

if [ $level -gt 0 ]; then
cd ${directory[$level]}
echo "returning to ${directory[level]}"
fi

}

level=0
display $1


Lloyd B.