ref: cd747191012d0420ac631340d962da1f80cef0a5
dir: /sys/src/libc/port/perror.c/
#include <u.h> #include <libc.h> void perror(char *s) { char buf[ERRMAX]; buf[0] = '\0'; errstr(buf, sizeof buf); if(s && *s) fprint(2, "%s: %s\n", s, buf); else fprint(2, "%s\n", buf); }