source: trunk/essentials/sys-apps/diffutils/src/util.c@ 3468

/* Support routines for GNU DIFF.

   Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1998, 2001, 2002
   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 this program; see the file COPYING.
   If not, write to the Free Software Foundation,
   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#include "diff.h"
#include <dirname.h>
#include <error.h>
#include <quotesys.h>
#include <regex.h>
#include <xalloc.h>

char const pr_program[] = PR_PROGRAM;

/* Queue up one-line messages to be printed at the end,
   when -l is specified.  Each message is recorded with a `struct msg'.  */

struct msg
{
  struct msg *next;
  char args[1]; /* Format + 4 args, each '\0' terminated, concatenated.  */
};

/* Head of the chain of queues messages.  */

static struct msg *msg_chain;

/* Tail of the chain of queues messages.  */

static struct msg **msg_chain_end = &msg_chain;


/* Use when a system call returns non-zero status.
   NAME should normally be the file name.  */

void
perror_with_name (char const *name)
{
  error (0, errno, "%s", name);
}

/* Use when a system call returns non-zero status and that is fatal.  */

void
pfatal_with_name (char const *name)
{
  int e = errno;
  print_message_queue ();
  error (EXIT_TROUBLE, e, "%s", name);
  abort ();
}

/* Print an error message containing MSGID, then exit.  */

void
fatal (char const *msgid)
{
  print_message_queue ();
  error (EXIT_TROUBLE, 0, "%s", _(msgid));
  abort ();
}


/* Like printf, except if -l in effect then save the message and print later.
   This is used for things like "Only in ...".  */

void
message (char const *format_msgid, char const *arg1, char const *arg2)
{
  message5 (format_msgid, arg1, arg2, 0, 0);
}

void
message5 (char const *format_msgid, char const *arg1, char const *arg2,
          char const *arg3, char const *arg4)
{
  if (paginate)
    {
      char *p;
      char const *arg[5];
      int i;
      size_t size[5];
      size_t total_size = offsetof (struct msg, args);
      struct msg *new;

      arg[0] = format_msgid;
      arg[1] = arg1;
      arg[2] = arg2;
      arg[3] = arg3 ? arg3 : "";
      arg[4] = arg4 ? arg4 : "";

      for (i = 0;  i < 5;  i++)
        total_size += size[i] = strlen (arg[i]) + 1;

      new = xmalloc (total_size);

      for (i = 0, p = new->args;  i < 5;  p += size[i++])
        memcpy (p, arg[i], size[i]);

      *msg_chain_end = new;
      new->next = 0;
      msg_chain_end = &new->next;
    }
  else
    {
      if (sdiff_merge_assist)
        putchar (' ');
      printf (_(format_msgid), arg1, arg2, arg3, arg4);
    }
}

/* Output all the messages that were saved up by calls to `message'.  */

void
print_message_queue (void)
{
  char const *arg[5];
  int i;
  struct msg *m = msg_chain;

  while (m)
    {
      struct msg *next = m->next;
      arg[0] = m->args;
      for (i = 0;  i < 4;  i++)
        arg[i + 1] = arg[i] + strlen (arg[i]) + 1;
      printf (_(arg[0]), arg[1], arg[2], arg[3], arg[4]);
      free (m);
      m = next;
    }
}


/* Call before outputting the results of comparing files NAME0 and NAME1
   to set up OUTFILE, the stdio stream for the output to go to.

   Usually, OUTFILE is just stdout.  But when -l was specified
   we fork off a `pr' and make OUTFILE a pipe to it.
   `pr' then outputs to our stdout.  */

static char const *current_name0;
static char const *current_name1;
static bool currently_recursive;

void
setup_output (char const *name0, char const *name1, bool recursive)
{
  current_name0 = name0;
  current_name1 = name1;
  currently_recursive = recursive;
  outfile = 0;
}

#if HAVE_WORKING_FORK || HAVE_WORKING_VFORK
static pid_t pr_pid;
#endif

void
begin_output (void)
{
  char *name;

  if (outfile != 0)
    return;

  /* Construct the header of this piece of diff.  */
  name = xmalloc (strlen (current_name0) + strlen (current_name1)
                  + strlen (switch_string) + 7);

  /* POSIX 1003.1-2001 specifies this format.  But there are some bugs in
     the standard: it says that we must print only the last component
     of the pathnames, and it requires two spaces after "diff" if
     there are no options.  These requirements are silly and do not
     match historical practice.  */
  sprintf (name, "diff%s %s %s", switch_string, current_name0, current_name1);

  if (paginate)
    {
      if (fflush (stdout) != 0)
        pfatal_with_name (_("write failed"));

      /* Make OUTFILE a pipe to a subsidiary `pr'.  */
      {
#if HAVE_WORKING_FORK || HAVE_WORKING_VFORK
        int pipes[2];

        if (pipe (pipes) != 0)
          pfatal_with_name ("pipe");

        pr_pid = vfork ();