#include <u.h>#include <libc.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++){		strcpy(p, argv[i]);		p += strlen(p);		if(i < argc-1)			*p++ = ' ';	}			if(!nflag)		*p++ = '\n'; 	if(write(1, buf, p-buf) < 0){		fprint(2, "echo: write error: %r\n");		exits("write error");	} 	exits((char *)0);}