How to remove all of the diacritics from a file?

Question

I have a file containing many vowels with diacritics. I need to make these replacements:

• Replace ā, á, ǎ, and à with a.
• Replace ē, é, ě, and è with

Answer 1

I like iconv as it handles all accents variations :

cat non-ascii.txt | iconv -f utf8 -t ascii//TRANSLIT//IGNORE > ascii.txt