path: root/rfc1524.c

/*
 * Copyright (C) 1996-8 Michael R. Elkins <me@cs.hmc.edu>
 * 
 *     This program 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 of the License, or
 *     (at your option) any later version.
 * 
 *     This program 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; if not, write to the Free Software
 *     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */ 

/* 
 * rfc1524 defines a format for the Multimedia Mail Configuration, which
 * is the standard mailcap file format under Unix which specifies what 
 * external programs should be used to view/compose/edit multimedia files
 * based on content type.
 *
 * This file contains various functions for implementing a fair subset of 
 * rfc1524.
 */

#include "mutt.h"
#include "rfc1524.h"

#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>
#include <string.h>

/* The command semantics include the following:
 * %s is the filename that contains the mail body data
 * %t is the content type, like text/plain
 * %{parameter} is replaced by the parameter value from the content-type field
 * \% is %
 * Unsupported rfc1524 parameters: these would probably require some doing
 * by mutt, and can probably just be done by piping the message to metamail
 * %n is the integer number of sub-parts in the multipart
 * %F is "content-type filename" repeated for each sub-part
 *
 * In addition, this function returns a 0 if the command works on a file,
 * and 1 if the command works on a pipe.
 */
int rfc1524_expand_command (BODY *a, char *_filename, char *_type,
    char *command, int clen)
{
  int x=0,y=0;
  int needspipe = TRUE;
  char buf[LONG_STRING];
  char filename[_POSIX_PATH_MAX];
  char type[LONG_STRING];
  
  strfcpy (filename, _filename, sizeof (filename));
  strfcpy (type, _type, sizeof (type));
  
  if (option (OPTMAILCAPSANITIZE))
  {
    mutt_sanitize_filename (filename);
    mutt_sanitize_filename (type);
  }
  
  while (command[x] && x<clen && y<sizeof(buf)) 
  {
    if (command[x] == '\\') {
      x++;
      buf[y++] = command[x++];
    }
    else if (command[x] == '%') 
    {
      x++;
      if (command[x] == '{') 
      {
	char param[STRING];
	char pvalue[STRING];
	char *_pvalue;
	int z = 0;

	x++;
	while (command[x] && command[x] != '}' && z<sizeof(param))
	  param[z++] = command[x++];
	param[z] = '\0';
	
	_pvalue = mutt_get_parameter (param, a->parameter);
	strfcpy (pvalue, NONULL(_pvalue), sizeof (pvalue));
	if (option (OPTMAILCAPSANITIZE))
	  mutt_sanitize_filename (pvalue);
	
	y += mutt_quote_filename (buf + y, sizeof (buf) - y, pvalue);
      }
      else if (command[x] == 's' && filename != NULL)
      {
	y += mutt_quote_filename (buf + y, sizeof (buf) - y, filename);
	needspipe = FALSE;
      }
      else if (command[x] == 't')
      {
	y += mutt_quote_filename (buf + y, sizeof (buf) - y, type);
      }
      x++;
    }
    else
      buf[y++] = command[x++];
  }
  buf[y] = '\0';
  strfcpy (command, buf, clen);

  return needspipe;
}

/* NUL terminates a rfc 1524 field,
 * returns start of next field or NULL */
static char *get_field (char *s)
{
  char *ch;

  if (!s)
    return NULL;

  while ((ch = strpbrk (s, ";\\")) != NULL)
  {
    if (*ch == '\\')
    {
      s = ch + 1;
      if (*s)
	s++;
    }
    else
    {
      *ch++ = 0;
      SKIPWS (ch);
      break;
    }
  }
  mutt_remove_trailing_ws (s);
  return ch;
}

static int get_field_text (char *field, char **entry,
			   char *type, char *filename, int line)
{
  field = mutt_skip_whitespace (field);
  if (*field == '=')
  {
    if (entry)
    {
      field++;
      field = mutt_skip_whitespace (field);
      safe_free ((void **) entry);
      *entry = safe_strdup (field);
    }
    return 1;
  }
  else 
  {
    mutt_error (_("Improperly formated entry for type %s in \"%s\" line %d"),
		type, filename, line);
    return 0;
  }
}

static int rfc1524_mailcap_parse (BODY *a,
				  char *filename,
				  char *type, 
				  rfc1524_entry *entry,
				  int opt)
{
  FILE *fp;
  char *buf = NULL;
  size_t buflen;
  char *ch;
  char *field;
  int found = FALSE;
  int copiousoutput;
  int composecommand;
  int editcommand;
  int printcommand;
  int btlen;
  int line = 0;

  /* rfc1524 mailcap file is of the format:
   * base/type; command; extradefs
   * type can be * for matching all
   * base with no /type is an implicit wild
   * command contains a %s for the filename to pass, default to pipe on stdin
   * extradefs are of the form:
   *  def1="definition"; def2="define \;";
   * line wraps with a \ at the end of the line
   * # for comments
   */

  /* find length of basetype */
  if ((ch = strchr (type, '/')) == NULL)
    return FALSE;
  btlen = ch - type;

  if ((fp = fopen (filename, "r")) != NULL)
  {
    while (!found && (buf = mutt_read_line (buf, &buflen, fp, &line)) != NULL)
    {
      /* ignore comments */
      if (*buf == '#')
	continue;
      dprint (2, (debugfile, "mailcap entry: %s\n", buf));

      /* check type */
      ch = get_field (buf);
      if (mutt_strcasecmp (buf, type) &&
	  (mutt_strncasecmp (buf, type, btlen) ||
	   (buf[btlen] != 0 &&			/* implicit wild */
	    mutt_strcmp (buf + btlen, "/*"))))	/* wildsubtype */
	continue;

      /* next field is the viewcommand */
      field = ch;
      ch = get_field (ch);
      if (entry)
	entry->command = safe_strdup (field);

      /* parse the optional fields */
      found = TRUE;