my solution to lab5

lab/user/testshell.c

@@ -0,0 +1,85 @@
+#include <inc/x86.h>
+#include <inc/lib.h>
+
+void wrong(int, int, int);
+
+void
+umain(int argc, char **argv)
+{
+	char c1, c2;
+	int r, rfd, wfd, kfd, n1, n2, off, nloff;
+	int pfds[2];
+
+	close(0);
+	close(1);
+	opencons();
+	opencons();
+
+	if ((rfd = open("testshell.sh", O_RDONLY)) < 0)
+		panic("open testshell.sh: %e", rfd);
+	if ((wfd = pipe(pfds)) < 0)
+		panic("pipe: %e", wfd);
+	wfd = pfds[1];
+
+	cprintf("running sh -x < testshell.sh | cat\n");
+	if ((r = fork()) < 0)
+		panic("fork: %e", r);
+	if (r == 0) {
+		dup(rfd, 0);
+		dup(wfd, 1);
+		close(rfd);
+		close(wfd);
+		if ((r = spawnl("/sh", "sh", "-x", 0)) < 0)
+			panic("spawn: %e", r);
+		close(0);
+		close(1);
+		wait(r);
+		exit();
+	}
+	close(rfd);
+	close(wfd);
+
+	rfd = pfds[0];
+	if ((kfd = open("testshell.key", O_RDONLY)) < 0)
+		panic("open testshell.key for reading: %e", kfd);
+
+	nloff = 0;
+	for (off=0;; off++) {
+		n1 = read(rfd, &c1, 1);
+		n2 = read(kfd, &c2, 1);
+		if (n1 < 0)
+			panic("reading testshell.out: %e", n1);
+		if (n2 < 0)
+			panic("reading testshell.key: %e", n2);
+		if (n1 == 0 && n2 == 0)
+			break;
+		if (n1 != 1 || n2 != 1 || c1 != c2)
+			wrong(rfd, kfd, nloff);
+		if (c1 == '\n')
+			nloff = off+1;
+	}
+	cprintf("shell ran correctly\n");
+
+	breakpoint();
+}
+
+void
+wrong(int rfd, int kfd, int off)
+{
+	char buf[100];
+	int n;
+
+	seek(rfd, off);
+	seek(kfd, off);
+
+	cprintf("shell produced incorrect output.\n");
+	cprintf("expected:\n===\n");
+	while ((n = read(kfd, buf, sizeof buf-1)) > 0)
+		sys_cputs(buf, n);
+	cprintf("===\ngot:\n===\n");
+	while ((n = read(rfd, buf, sizeof buf-1)) > 0)
+		sys_cputs(buf, n);
+	cprintf("===\n");
+	exit();
+}
+