[SOLVED] Change date modified of multiple folders to match that of their most recently modified file

Issue

I've been using the following shell bin/bash script as an app which I can drop a folder on, and it will update the date modified of the folder to match the most recently modified file in that folder.

for f in each "$@"
do
    echo "$f"
done
$HOME/setMod "$@"

This gets the folder name, and then passes it to this setMod script in my home folder.

#!/bin/bash
# Check that exactly one parameter has been specified - the directory
if [ $# -eq 1 ]; then
   # Go to that directory or give up and die
   cd "$1" || exit 1
   # Get name of newest file
   newest=$(stat -f "%m:%N" * | sort -rn | head -1 | cut -f2 -d:)
   # Set modification date of folder to match
   touch -r "$newest" .
fi

However, if I drop more than one folder on it at a time, it won't work, and I can't figure out how to make it work with multiple folders at once.

Also, I learned from Apple Support that the reason so many of my folders keep getting the mod date updated is due to some Time Machine-related process, despite the fact I haven't touched some of them in years. If anyone knows of a way to prevent this from happening, or to somehow automatically periodically update the date modified of folders to match the date/time of the most-recently-modified file in them, that would save me from having to run this step manually pretty regularly.

Solution

The setMod script current accepts only one parameter. You could either make it accept many parameters and loop over them, or you could make the calling script use a loop.

I take the second option, because the caller script has some mistakes and weak points. Here it is corrected and extended for your purpose:

for dir; do
    echo "$dir"
    "$HOME"/setMod "$dir"
done

Or to make setMod accept multiple parameters:

#!/bin/bash

setMod() {
   cd "$1" || return 1
   # Get name of newest file
   newest=$(stat -f "%m:%N" * | sort -rn | head -1 | cut -f2 -d:)
   # Set modification date of folder to match
   touch -r "$newest" .
}

for dir; do
   if [ ! -d "$dir" ]; then
       echo not a directory, skipping: $dir
       continue
   fi

   (setMod "$dir")
done

Notes:

• for dir; do is equivalent to for dir in "$@"; do
• The parentheses around (setMod "$dir") make it run in a sub-shell, so that the script itself doesn't change the working directory, the effect of the cd operation is limited to the sub-shell within (...)

Answered By - janos

Answer Checked By - Dawn Plyler (WPSolving Volunteer)