extern long kclose(int); extern int kdial(char*, char*, char*, int*); extern void kerrstr(char*); extern void kgerrstr(char*); extern long kopen(char*, int); extern long kread(int, void*, long); extern long kseek(int, vlong, int); extern long kwrite(int, void*, long); extern void kwerrstr(char *, ...); extern char* strdup(char*); extern char* strrchr(char*, char); extern char* strstr(char*, char*); extern int newfd(Chan*);