#include "system.h" extern int sys_nerr; extern char *sys_errlist[]; static char buf[64]; char * strerror(int errnum) { if (errnum < 0 || errnum > sys_nerr) { static char fmt[] = "Unknown error %d"; size_t len = (size_t) sprintf (buf, fmt, errnum); if (len < (size_t) sizeof(fmt) - 2) return NULL; buf[len - 1] = '\0'; return buf; } return (char *) sys_errlist[errnum]; }