#include <u.h>#include <libc.h>#include <auth.h> voidusage(void){	fprint(2, "usage:\n\t%s user pass\n\t%s authorization\n", argv0, argv0);	exits("usage");} voidmain(int argc, char *argv[]){	char *a, *s;	int n; 	ARGBEGIN {	} ARGEND 	switch(argc){	default:		usage();		return;	case 2:		s = argv[0];		a = argv[1];		break;	case 1:		a = argv[0];		if(cistrncmp(a, "Basic ", 6) == 0)			a += 6;		n = strlen(a);		if((s = malloc(n+1)) == nil)			sysfatal("out of memory");		if((n = dec64((uchar*)s, n, a, n)) <= 0)			sysfatal("bad base64");		s[n] = '\0';		if((a = strchr(s, ':')) == nil)			sysfatal("bad format");		*a++ = '\0';		break;	}	if(*s == '\0')		sysfatal("empty username");	if(auth_userpasswd(s, a) == nil)		sysfatal("bad password");	print("%s\n", s);	exits(nil);}