add directory study

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

@@ -0,0 +1,157 @@
+/* tr - translate characters		Author: Michiel Huisjes */
+/* Usage: tr [-cds] [string1 [string2]]
+ *	c: take complement of string1
+ *	d: delete input characters coded string1
+ *	s: squeeze multiple output characters of string2 into one character
+ */
+
+#define BUFFER_SIZE	1024
+#define ASCII		0377
+
+typedef char BOOL;
+#define TRUE	1
+#define FALSE	0
+
+#define NIL_PTR		((char *) 0)
+
+BOOL com_fl, del_fl, sq_fl;
+
+unsigned char output[BUFFER_SIZE], input[BUFFER_SIZE];
+unsigned char vector[ASCII + 1];
+BOOL invec[ASCII + 1], outvec[ASCII + 1];
+
+short in_index, out_index;
+
+main(argc, argv)
+int argc;
+char *argv[];
+{
+  register unsigned char *ptr;
+  int index = 1;
+  short i;
+
+  if (argc > 1 && argv[index][0] == '-') {
+	for (ptr = (unsigned char *) &argv[index][1]; *ptr; ptr++) {
+		switch (*ptr) {
+		    case 'c':	com_fl = TRUE;	break;
+		    case 'd':	del_fl = TRUE;	break;
+		    case 's':	sq_fl = TRUE;	break;
+		    default:
+			write(2,"Usage: tr [-cds] [string1 [string2]].\n", 38);
+			exit(1);
+		}
+	}
+	index++;
+  }
+  for (i = 0; i <= ASCII; i++) {
+	vector[i] = i;
+	invec[i] = outvec[i] = FALSE;
+  }
+
+  if (argv[index] != NIL_PTR) {
+	expand(argv[index++], input);
+	if (com_fl) complement(input);
+	if (argv[index] != NIL_PTR) expand(argv[index], output);
+	if (argv[index] != NIL_PTR) map(input, output);
+	for (ptr = input; *ptr; ptr++) invec[*ptr] = TRUE;
+	for (ptr = output; *ptr; ptr++) outvec[*ptr] = TRUE;
+  }
+  convert();
+}
+
+convert()
+{
+  short read_chars = 0;
+  short c, coded;
+  short last = -1;
+
+  for (;;) {
+	if (in_index == read_chars) {
+		if ((read_chars = read(0, input, BUFFER_SIZE)) <= 0) {
+			if (write(1, output, out_index) != out_index)
+				write(2, "Bad write\n", 10);
+			exit(0);
+		}
+		in_index = 0;
+	}
+	c = input[in_index++];
+	coded = vector[c];
+	if (del_fl && invec[c]) continue;
+	if (sq_fl && last == coded && outvec[coded]) continue;
+	output[out_index++] = last = coded;
+	if (out_index == BUFFER_SIZE) {
+		if (write(1, output, out_index) != out_index) {
+			write(2, "Bad write\n", 10);
+			exit(1);
+		}
+		out_index = 0;
+	}
+  }
+
+  /* NOTREACHED */
+}
+
+map(string1, string2)
+register unsigned char *string1, *string2;
+{
+  unsigned char last;
+
+  while (*string1) {
+	if (*string2 == '\0')
+		vector[*string1] = last;
+	else
+		vector[*string1] = last = *string2++;
+	string1++;
+  }
+}
+
+expand(arg, buffer)
+register char *arg;
+register unsigned char *buffer;
+{
+  int i, ac;
+
+  while (*arg) {
+	if (*arg == '\\') {
+		arg++;
+		i = ac = 0;
+		if (*arg >= '0' && *arg <= '7') {
+			do {
+				ac = (ac << 3) + *arg++ - '0';
+				i++;
+			} while (i < 4 && *arg >= '0' && *arg <= '7');
+			*buffer++ = ac;
+		} else if (*arg != '\0')
+			*buffer++ = *arg++;
+	} else if (*arg == '[') {
+		arg++;
+		i = *arg++;
+		if (*arg++ != '-') {
+			*buffer++ = '[';
+			arg -= 2;
+			continue;
+		}
+		ac = *arg++;
+		while (i <= ac) *buffer++ = i++;
+		arg++;		/* Skip ']' */
+	} else
+		*buffer++ = *arg++;
+  }
+}
+
+complement(buffer)
+unsigned char *buffer;
+{
+  register unsigned char *ptr;
+  register short i, index;
+  unsigned char conv[ASCII + 2];
+
+  index = 0;
+  for (i = 1; i <= ASCII; i++) {
+	for (ptr = buffer; *ptr; ptr++)
+		if (*ptr == i) break;
+	if (*ptr == '\0') conv[index++] = i & ASCII;
+  }
+  conv[index] = '\0';
+  strcpy(buffer, conv);
+}