ref: 5df1214b19e2a69d3aff7a5924c422ff2c0dfa1c
dir: /sys/src/libc/port/cistrstr.c/
#include <u.h> #include <libc.h> char* cistrstr(char *s, char *sub) { int c, csub, n; csub = *sub; if(csub == '\0') return s; if(csub >= 'A' && csub <= 'Z') csub -= 'A' - 'a'; sub++; n = strlen(sub); for(; c = *s; s++){ if(c >= 'A' && c <= 'Z') c -= 'A' - 'a'; if(c == csub && cistrncmp(s+1, sub, n) == 0) return s; } return nil; }