normal.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

/* Normal-format output routines for GNU DIFF.
   Copyright (C) 1988, 1989, 1993 Free Software Foundation, Inc.

This file is part of GNU DIFF.

GNU DIFF is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU DIFF is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU DIFF; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */


#include "diff.h"

static void print_normal_hunk PARAMS((struct change *));

/* Print the edit-script SCRIPT as a normal diff.
   INF points to an array of descriptions of the two files.  */

void
print_normal_script (script)
     struct change *script;
{
  print_script (script, find_change, print_normal_hunk);
}

/* Print a hunk of a normal diff.
   This is a contiguous portion of a complete edit script,
   describing changes in consecutive lines.  */

static void
print_normal_hunk (hunk)
     struct change *hunk;
{
  int first0, last0, first1, last1, deletes, inserts;
  register int i;

  /* Determine range of line numbers involved in each file.  */
  analyze_hunk (hunk, &first0, &last0, &first1, &last1, &deletes, &inserts);
  if (!deletes && !inserts)
    return;

  begin_output ();

  /* Print out the line number header for this hunk */
  print_number_range (',', &files[0], first0, last0);
  fprintf (outfile, "%c", change_letter (inserts, deletes));
  print_number_range (',', &files[1], first1, last1);
  fprintf (outfile, "\n");

  /* Print the lines that the first file has.  */
  if (deletes)
    for (i = first0; i <= last0; i++)
      print_1_line ("<", &files[0].linbuf[i]);

  if (inserts && deletes)
    fprintf (outfile, "---\n");

  /* Print the lines that the second file has.  */
  if (inserts)
    for (i = first1; i <= last1; i++)
      print_1_line (">", &files[1].linbuf[i]);
}