You can use the continue keyword to skip the rest of the current iteration and start the next one, if there is any. For example, this code gets the size of every one of a set of directories, but it only runs du if the directory actually exists:
#!/bin/bash
dirs=(/bin /home /mnt /opt /usr)
for dir in "${dirs[@]}" ; do
[[ -d $dir ]] || continue
du -s -- "$dir"
done
The continue keyword skips to the next run of the loop if the directory does not exist. It uses the || control operator to do this; if you prefer, you could write it with a full if statement instead.
As well as testing for the general case of file existence or type, loop continuations such as this are a useful method for dealing with unexpanded glob patterns. ...
