/* WARNING: assumes machine is little endian */

/* arx: extract pdp-11 ar archive */

#include <u.h>
#include <libc.h>

#define min(a, b) ((a) < (b) ? (a) : (b))

struct head
{
	char name[8];
	int time;
	uchar uid;
	uchar mode;
	ushort size;
};

void
usage(void)
{
	fprint(2, "%s: ar-file\n", argv0);
	exits("usage");
}

void
x(int in, char *name, int sz)
{
	char nam[9];
	uchar buf[512];
	int out;
	int n;

	memcpy(nam, name, 8);
	nam[8] = '\0';
	out = create(nam, OWRITE, 0666);
	if(out < 0)
		sysfatal("cannot create %s", nam);
	while(sz > 0){
		n = read(in, buf, min(512, sz));
		write(out, buf, n);
		sz -= n;
	}
	close(out);
}

void
main(int argc, char *argv[])
{
	ushort magic;
	struct head h;
	int fd;

	argv0 = argv[0];
	if(argc < 2)
		usage();
	fd = open(argv[1], OREAD);
	if(fd < 0)
		sysfatal("cannot open %s", argv[1]);
	read(fd, &magic, 2);
	if(magic != 0177555)
		sysfatal("wrong magic: %o", magic);
	while(read(fd, &h, 16) == 16){
		print("%.8s %d\n", h.name, h.size);
		x(fd, h.name, h.size);
	}

	close(fd);

	exits(nil);
}