add directory study

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

@@ -0,0 +1,62 @@
+/* tee - pipe fitting			Author: Paul Polderman */
+
+#include <sys/types.h>
+#include <fcntl.h>
+#include <blocksize.h>
+#include <signal.h>
+#include <unistd.h>
+
+#define	MAXFD	18
+
+int fd[MAXFD];
+
+main(argc, argv)
+int argc;
+char **argv;
+{
+  char iflag = 0, aflag = 0;
+  char buf[BLOCK_SIZE];
+  int i, s, n;
+
+  argv++;
+  --argc;
+  while (argc > 0 && argv[0][0] == '-') {
+	switch (argv[0][1]) {
+	    case 'i':		/* Interrupt turned off. */
+		iflag++;
+		break;
+	    case 'a':		/* Append to outputfile(s), instead of
+			 * overwriting them. */
+		aflag++;
+		break;
+	    default:
+		std_err("Usage: tee [-i] [-a] [files].\n");
+		exit(1);
+	}
+	argv++;
+	--argc;
+  }
+  fd[0] = 1;			/* Always output to stdout. */
+  for (s = 1; s < MAXFD && argc > 0; --argc, argv++, s++) {
+	if (aflag && (fd[s] = open(*argv, O_RDWR)) >= 0) {
+		lseek(fd[s], 0L, SEEK_END);
+		continue;
+	} else {
+		if ((fd[s] = creat(*argv, 0666)) >= 0) continue;
+	}
+	std_err("Cannot open output file: ");
+	std_err(*argv);
+	std_err("\n");
+	exit(2);
+  }
+
+  if (iflag) signal(SIGINT, SIG_IGN);
+
+  while ((n = read(0, buf, BLOCK_SIZE)) > 0) {
+	for (i = 0; i < s; i++) write(fd[i], buf, n);
+  }
+
+  for (i = 0; i < s; i++)	/* Close all fd's */
+	close(fd[i]);
+  exit(0);
+}