ref: a98f911a178d3cc044d612e5ad96ee487bd887c8
dir: /sys/src/libc/port/u16.c/
#include <u.h> #include <libc.h> static char t16e[] = "0123456789ABCDEF"; int dec16(uchar *out, int lim, char *in, int n) { int c, w = 0, i = 0; uchar *start = out; uchar *eout = out + lim; while(n-- > 0){ c = *in++; if('0' <= c && c <= '9') c = c - '0'; else if('a' <= c && c <= 'z') c = c - 'a' + 10; else if('A' <= c && c <= 'Z') c = c - 'A' + 10; else continue; w = (w<<4) + c; i++; if(i == 2){ if(out + 1 > eout) goto exhausted; *out++ = w; w = 0; i = 0; } } exhausted: return out - start; } int enc16(char *out, int lim, uchar *in, int n) { uint c; char *eout = out + lim; char *start = out; while(n-- > 0){ c = *in++; if(out + 2 >= eout) goto exhausted; *out++ = t16e[c>>4]; *out++ = t16e[c&0xf]; } exhausted: *out = 0; return out - start; }