#include <lib9.h> voidmain(int argc, char *argv[]){	int nflag;	int i, len;	char *buf, *p; 	nflag = 0;	if(argc > 1 && strcmp(argv[1], "-n") == 0)		nflag = 1; 	len = 1;	for(i = 1+nflag; i < argc; i++)		len += strlen(argv[i])+1; 	buf = malloc(len);	if(buf == 0)		exits("no memory"); 	p = buf;	for(i = 1+nflag; i < argc; i++)		p += sprint(p, i == argc-1 ? "%s":"%s ", argv[i]);			if(!nflag)		sprint(p, "\n"); 	if(write(1, buf, strlen(buf)) < 0)		fprint(2, "echo: write error: %r\n"); 	exits((char *)0);}