sys/libunicode/findrune.c


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#include "internal.h"

byte*
utf8·findrune(byte* s, long c)
{
    long c1;
    rune r;
    int  n;

    if (c < RuneSync) return strchr(s, c);

    for (;;) {
        c1 = *(ubyte*)s;
        if (c1 < RuneSelf) {
            if (c1 == 0) return nil;
            if (c1 == c) return s;
            s++;
            continue;
        }
        n = utf8·bytetorune(&r, s);
        if (r == c) return s;
        s += n;
    }

    return nil;
}