Version: wc (GNU coreutils) 8.21 When 'wc -m' is invoked, it should print character count, but it counts incorrectly UTF-8 encoded characters. Attached files have 3, 4 an 6 bytes in them, but all have only two UTF-8 encoded characters, which you can see with any modern text editor. wc -c chows correct number of bytes: wc -c * 3 3bytes.txt 4 4bytes.txt 6 6bytes.txt 13 total But wc -m shows incorrect number of characters: wc -m * 3 3bytes.txt 3 4bytes.txt 3 6bytes.txt 9 total But should be: wc -m * 2 3bytes.txt 2 4bytes.txt 2 6bytes.txt 6 total I am using Lubuntu 14.04.2 LTS (lsb_release reports Ubuntu), x86_64 GNU/Linux 3.13.0-53-generic kernel P.S. If attachments will not pass through system, you can test it by creating files with following content: 3bytes.txt: aa 4bytes.txt: aā 6bytes.txt: a𐄈