printf width modifier for special characters

Question

i have a problem with printf width modifier in C

example:

char a[] = "o", b[] = "l";

printf("%-3s %s", a, b);

console output gives me 3 spaces between strings, but when I change "o" to "ó", console shows 2 spaces between. Every time i use character like "ł", "ó", "ś" in the string, width modifier is shortened by 1 sign, why this happens?

OS X 10.11 (El Captain)

Mac OSX uses UTF-8 encoding, therefore each code point uses a variable number of *bytes* - the word `char` is misleading, meaning both a byte and a character of the *basic execution character set*; however, not all extended characters can be represented by a single 8-bit byte. — Antti Haapala -- Слава Україні, Oct 01 '17 at 09:34

score 3 · Answer 1 · answered Oct 01 '17 at 09:18

"Special" characters as you are showing them need more bytes (char) to be represented in a string. Your arbitrary limit of 3 is not enough, raise it to some suitable value.

In addition, the way and length that such special characters are represented depends on the system. For portable code you should never make such arbitrary assumptions.

printf width modifier for special characters

1 Answers1