substr + utf

b888 has asked for the wisdom of the Perl Monks concerning the following question:

Greetings.

What is the best way to make substr on strings, that contain utf8(16/32) symbols? So "substr"ed part will contain valid utf symbols after this operation.

Thanks

Comment on substr + utf

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Re: substr + utf by halley (Prior) on Aug 18, 2005 at 16:29 UTC
Until Perl knows that a given scalar intentionally contains utf8-encoded characters, it may not act on that assumption. See Encode and perldoc perlunicode. -- `[ e d @ h a l l e y . c c ]`	[reply]
Re: substr + utf by ikegami (Patriarch) on Aug 18, 2005 at 16:09 UTC
`substr` works on characters, not bytes, so you don't have to do anything special.	[reply] [d/l]
Re^2: substr + utf by b888 (Beadle) on Aug 18, 2005 at 16:19 UTC
Made several tests before posting - at least on my PC it works with utf8 symbols as if it is 2 chars. Maybe it depends on some OS settings?	[reply]
Re^3: substr + utf by ikegami (Patriarch) on Aug 18, 2005 at 16:28 UTC
Are you sure the string is actually unicode? I think you interpreted every byte of your input as a character instead of interpreting your input as a unicode string. I'm not sure how to convert from one to the other. Maybe it depends on some OS settings? I doubt it. Try the following code. `# $str = Approximation of "Eric" in Katakana. $str = "\x{30A8}\x{30FC}\x{30EA}\x{30AF}"; print(length($str), "\n"); # 4 $ch = substr($str, 0, 1); print(($ch eq "\x{30A8}" ? "equal" : "not equal"), "\n"); # equal` [download]	[reply] [d/l]