Linux shell: find -exec in find -exec

As for the find command, you can also just add more -exec commands in a row:

find . -name "*" -exec chgrp -v new_group '{}' \; -exec chmod -v 770 '{}' \;

Note that this command is, in its result, equivalent of using

chgrp -v new_group file && chmod -v 770 file

on each file.

All the find's parameters such as -name, -exec, -size and so on, are actually tests: find will continue to run them one by one as long as the entire chain so far has evaluated to true. So each consecutive -exec command is executed only if the previous ones returned true (i.e. 0 exit status of the commands). But find also understands logic operators such as or (-o) and not (!). Therefore, to use a chain of -exec tests regardless of the previous results, one would need to use something like this:

find . -name "*" \( -exec chgrp -v new_group {} \; -o -true \) -exec chmod -v 770 {} \; 

In:

find -type f -name "*.txt" -exec sh -c 'mv -v "${0%/*}" ../bar' {} \;

find opens the current directory (.), gets the content (list1). Then goes on to process that list. It processes dir6; as that file is a directory, it chdirs into it, opens it gets a second list of files (list2), processes file.txt and does:

mv -v ./dir6 ../bar

Now, find's current directory has not changed, but its path has changed: it is now ../bar/dir6. After finishing traversing the content of dir6, it goes back up (chdir("..")) and is now in ../bar. find detects that the directory is not the same as before and exits.