add directory study

study/linux-travel/MINIX-1.5/1.5/Source/commands/mount.c

@@ -0,0 +1,67 @@
+/* mount - mount a file system		Author: Andy Tanenbaum */
+
+#include <errno.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#define BUFSIZE 1024
+
+extern int errno;
+char *mounttable = "/etc/mtab";
+char buffer[BUFSIZE];
+
+main(argc, argv)
+int argc;
+char *argv[];
+{
+  int ro, fd;
+
+  if (argc == 1) list();
+  if (argc < 3 || argc > 4) usage();
+  if (argc == 4 && *argv[3] != '-' && *(argv[3] + 1) != 'r') usage();
+  ro = (argc == 4 ? 1 : 0);
+  if (mount(argv[1], argv[2], ro) < 0) {
+	if (errno == EINVAL) {
+		std_err("mount: ");
+		std_err(argv[1]);
+		std_err(" is not a valid file system.\n");
+	} else {
+		perror("mount");
+	}
+	exit(1);
+  }
+  std_err(argv[1]);
+  std_err(" mounted\n");
+  if ((fd = open(mounttable, O_RDWR)) < 0) exit(1);
+  lseek(fd, 0L, SEEK_END);	/* seek to EOF */
+  write(fd, argv[1], strlen(argv[1]));
+  write(fd, " is mounted on ", 15);
+  write(fd, argv[2], strlen(argv[2]));
+  write(fd, "\n", 1);
+  exit(0);
+}
+
+
+list()
+{
+  int fd, n;
+
+  fd = open(mounttable, O_RDONLY);
+  if (fd < 0) {
+	std_err("mount: cannot open ");
+	std_err(mounttable);
+	std_err("\n");
+	exit(1);
+  }
+  n = read(fd, buffer, BUFSIZE);
+  write(1, buffer, n);
+  exit(0);
+}
+
+
+usage()
+{
+  std_err("Usage: mount special name [-r]\n");
+  exit(1);
+}