Plan 9 from Bell Labs’s /usr/web/sources/contrib/rsc/linuxemu/libc/port/perror.c
#include <u.h> #include <libc.h> void perror(char *s) { char buf[ERRLEN]; buf[0] = 0; errstr(buf); if(s && *s) fprint(2, "%s: %s\n", s, buf); else fprint(2, "%s\n", buf); }