- .TH scan_utf8 3
- .SH NAME
- scan_utf8 \- decode an unsigned integer from UTF-8 encoding
- .SH SYNTAX
- .B #include <scan.h>
- size_t \fBscan_utf8\fP(const char *\fIsrc\fR,size_t \fIlen\fR,uint32_t *\fIdest\fR);
- .SH DESCRIPTION
- scan_utf8 decodes an unsigned integer in UTF-8 encoding from a memory
- area holding binary data. It writes the decode value in \fIdest\fR and
- returns the number of bytes it read from \fIsrc\fR.
- scan_utf8 never reads more than \fIlen\fR bytes from \fIsrc\fR. If the
- sequence is longer than that, or the memory area contains an invalid
- sequence, scan_utf8 returns 0 and does not touch \fIdest\fR.
- The length of the longest UTF-8 sequence is 5. If the buffer is longer
- than that, and scan_utf8 fails, then the data was not a valid UTF-8
- encoded sequence.
- .SH NOTE
- fmt_utf8 and scan_utf8 implement the encoding from UTF-8, but are meant
- to be able to store integers, not just Unicode code points. Values
- above 0x10ffff are not valid UTF-8. If you are using this function to
- parse UTF-8, you need to reject them (see RFC 3629).
- .SH "SEE ALSO"