How to change suffix of the files

for x in /path/to/*.example
do
  cp "$x" "${x%%.example}"
done

Will make a copy without the .example into the same folder as the source file.

You can use the prename command to rename files based on a transformation written in Perl.

Let's start simple. To rename all the .jpg files in a directory, changing all - to _, we can just use the s operator (we could also use tr). The Perl code is executed to transform each file name.

prename 's!-!_!g' *.jpg

To change the number sequence(s) at the end to a simple counter, we introduce a counter variable. I use the global variable $a as a counter (introducing extra variables is more complicated). The regular expression (\.[^/.]*)$ matches the file extension, and $1 in the replacement text stands for what the parenthesized group matched.

prename 's!-!_!g; ++$a; s!_[0-9_]+(\.[^/.]*)$!_$a$1!' *.jpg

Note that the files are renamed in the order given by the file name arguments, i.e. the order of expansion of *.jpg determines the numbering of the files.

Alternatively, we can initialize the counter explicitly with a BEGIN block.

prename 'BEGIN {$a = 1;} s!-!_!g; s!_[0-9_]+(\.[^/.]*)$!_$a$1!; ++$a;' *.jpg

To perform this in every subdirectory of the current directory, call find.

find -type d -exec sh -c 'cd "$1" && prename "$0" *.jpg' 's!-!_!g; ++$a; s!_[0-9_]+(\.[^/.]*)$!_$a$1!' {} \;