#include <u.h>#include <libc.h>#include <ctype.h> /* *  make an address, add the defaults */char *netmkaddr(char *linear, char *defnet, char *defsrv){	static char addr[256];	char *cp; 	/*	 *  dump network name	 */	cp = strchr(linear, '!');	if(cp == 0){		if(defnet == 0)			defnet = "net";		/* allow unix sockets to omit unix! prefix */		if(access(linear, 0) >= 0){			snprint(addr, sizeof(addr), "unix!%s", linear);			return addr;		}		/* allow host:service in deference to Unix convention */		if((cp = strchr(linear, ':')) != nil){			snprint(addr, sizeof(addr), "%s!%.*s!%s", 				defnet, utfnlen(linear, cp-linear),				linear, cp+1);			return addr;		}		if(defsrv)			snprint(addr, sizeof(addr), "%s!%s!%s",				defnet, linear, defsrv);		else			snprint(addr, sizeof(addr), "%s!%s", defnet, linear);		return addr;	} 	/*	 *  if there is already a service, use it	 */	cp = strchr(cp+1, '!');	if(cp)		return linear; 	/*	 * if the network is unix, no service	 */	if(strncmp(linear, "unix!", 5) == 0)		return linear; 	/*	 *  add default service	 */	if(defsrv == 0)		return linear; 	snprint(addr, sizeof(addr), "%s!%s", linear, defsrv);	return addr;}