#include <lib9.h>

#define	DEFB	(8*1024)

void	copy(char *from, char *to, int todir);
void	copy1(int fdf, int fdt, char *from, char *to);
void	fixbackslash(char *file);

void
main(int argc, char *argv[])
{
	Dir dirb;
	int todir, i;

	if(argc<3){
		fprint(2, "usage:\tcp fromfile tofile\n");
		fprint(2, "\tcp fromfile ... todir\n");
		exits("usage");
	}

	for(i=0; i<argc; i++)
		fixbackslash(argv[i]);


	todir=0;
	if(dirstat(argv[argc-1], &dirb)==0 && (dirb.mode&CHDIR))
		todir=1;
	if(argc>3 && !todir){
		fprint(2, "cp: %s not a directory\n", argv[argc-1]);
		exits("bad usage");
	}
	for(i=1; i<argc-1; i++)
		copy(argv[i], argv[argc-1], todir);
	exits(0);
}

void
copy(char *from, char *to, int todir)
{
	Dir dirb, dirt;
	char name[256];
	int fdf, fdt;

	if(todir){
		char *s, *elem;
		elem=s=from;
		while(*s++)
			if(s[-1]=='/')
				elem=s;
		sprint(name, "%s/%s", to, elem);
		to=name;
	}
	if(dirstat(from, &dirb)!=0){
		fprint(2,"cp: can't stat %s: %r\n", from);
		return;
	}
	if(dirb.mode&CHDIR){
		fprint(2, "cp: %s is a directory\n", from);
		return;
	}
	dirb.mode &= 0777;
	if(dirstat(to, &dirt)==0)
	if(dirb.qid.path==dirt.qid.path && dirb.qid.vers==dirt.qid.vers)
	if(dirb.dev==dirt.dev && dirb.type==dirt.type){
		fprint(2, "cp: %s and %s are the same file\n", from, to);
		return;
	}
	fdf=open(from, OREAD);
	if(fdf<0){
		fprint(2, "cp: can't open %s: %r\n", from);
		return;
	}
	fdt=create(to, OWRITE, dirb.mode);
	if(fdt<0){
		fprint(2, "cp: can't create %s: %r\n", to);
		close(fdf);
		return;
	}
	copy1(fdf, fdt, from, to);
	close(fdf);
	close(fdt);
}

void
copy1(int fdf, int fdt, char *from, char *to)
{
	char *buf;
	long n, n1, rcount;

	buf = malloc(DEFB);
	/* clear any residual error */
	memset(buf, 0, ERRLEN);
	errstr(buf);
	for(rcount=0;; rcount++) {
		n = read(fdf, buf, DEFB);
		if(n <= 0)
			break;
		n1 = write(fdt, buf, n);
		if(n1 != n) {
			fprint(2, "cp: error writing %s: %r\n", to);
			break;
		}
	}
	if(n < 0) 
		fprint(2, "cp: error reading %s: %r\n", from);
	free(buf);
}

void
fixbackslash(char *file)
{
	char *p;
	
	for(p=file; *p; p++)
		if(*p == '\\')
			*p = '/';
}