Searching for non-ascii characters

Question

I have a file, a.out, which contains a number of lines. Each line is one character only, either the unicode character U+2013 or a lower case letter a-z

Answer 1

I recommend avoiding dodgy grep -P implementations and use the real thing. This works:

perl -CSD -nle 'print "$.: $_" if /\P{ASCII}/' utfile1 utfile2 utfile3 ...

Where:

• The -CSD options says that both the stdio trio (stdin, stdout, stderr) and disk files should be treated as UTF-8 encoded.

• The $. represents the current record (line) number.

• The $_ represents the current line.

• The \P{ASCII} matches any code point that is not ASCII.