Filenames with spaces in bash

for x in *.png;
do
fn=`basename "${x}" .png | sed 's/ /\\ /g'`
convert "${fn}.png" "${fn}.jpg"
done


Multiple Comparison in Bash

Checking multiple conditions in Bash can be tricky.

Following require STRING1 and STRING2 to be not empty and COUNTER < MAX.
if [[ -n "$STRING1" && -n "$STRING2" && $COUNTER -lt $MAX ]];
then
...
fi

This post is a nice concise resource.

Apply Commands Only to All Files or Directories

Choose "type" to be "d" (directory) or "f" (file).
find . -type "type" -exec chmod 755 {} \; 
find . -type "type" -exec chown owner.group {} \;

More generally, any "command" will work, too.
find . -type "type" -exec "command" {} \;

Running Commands in a Sub-shell

Content is from this post

Here is how to run "/bin/script.sh" inside "/workingdir" without changing your current path.
(cd /workingdir; /bin/script.sh)

Here is how to run sequence of commands with checking status after each command by inserting "&&"
(cd /workingdir && /bin/script.sh)

Memory is better managed by using "exec" command.
(cd /workingdir && exec /bin/script.sh)