php -r 'echo strip_tags(file_get_contents($argv[1]));' file_to_strip
And as an alias:
alias strip_tags="php -r 'echo strip_tags(file_get_contents(\$argv[1]));'"
php -r 'echo strip_tags(file_get_contents($argv[1]));' file_to_strip
And as an alias:
alias strip_tags="php -r 'echo strip_tags(file_get_contents(\$argv[1]));'"