add directory study

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

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+/*  expand - expand tabs to spaces	Author: Terrence W. Holm */
+
+/*  Usage:  expand  [ -tab1,tab2,tab3,... ]  [ file ... ]  */
+
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+
+#define MAX_TABS 32
+
+int column = 0;			/* Current column, retained between files  */
+
+main(argc, argv)
+int argc;
+char *argv[];
+{
+  int tabs[MAX_TABS];
+  int tab_index = 0;		/* Default one tab   */
+  int i;
+  FILE *f;
+
+  tabs[0] = 8;			/* Default tab stop  */
+
+  if (argc > 1 && argv[1][0] == '-') {
+	char *p = argv[1];
+	int last_tab_stop = 0;
+
+	for (tab_index = 0; tab_index < MAX_TABS; ++tab_index) {
+		if ((tabs[tab_index] = atoi(p + 1)) <= last_tab_stop) {
+			fprintf(stderr, "Bad tab stop spec\n");
+			exit(1);
+		}
+		last_tab_stop = tabs[tab_index];
+
+		if ((p = strchr(p + 1, ',')) == NULL) break;
+	}
+
+	--argc;
+	++argv;
+  }
+  if (argc == 1)
+	Expand(stdin, tab_index, tabs);
+  else
+	for (i = 1; i < argc; ++i) {
+		if ((f = fopen(argv[i], "r")) == NULL) {
+			perror(argv[i]);
+			exit(1);
+		}
+		Expand(f, tab_index, tabs);
+		fclose(f);
+	}
+
+  exit(0);
+}
+
+
+Expand(f, tab_index, tabs)
+FILE *f;
+int tab_index;
+int tabs[];
+{
+  int next;
+  int c;
+  int i;
+
+  while ((c = getc(f)) != EOF) {
+	if (c == '\t') {
+		if (tab_index == 0)
+			next = (column / tabs[0] + 1) * tabs[0];
+		else {
+			for (i = 0; i <= tab_index && tabs[i] <= column; ++i);
+
+			if (i > tab_index)
+				next = column + 1;
+			else
+				next = tabs[i];
+		}
+
+		do {
+			++column;
+			putchar(' ');
+		} while (column < next);
+
+		continue;
+	}
+	if (c == '\b')
+		column = column > 0 ? column - 1 : 0;
+	else if (c == '\n' || c == '\r')
+		column = 0;
+	else
+		++column;
+
+	putchar(c);
+  }
+}