wget/src/init.c

/* Reading/parsing the initialization file.
   Copyright (C) 1995, 1996, 1997, 1998, 2000, 2001
   Free Software Foundation, Inc.

This file is part of GNU Wget.

GNU Wget 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.

GNU Wget 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 Wget; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

In addition, as a special exception, the Free Software Foundation
gives permission to link the code of its release of Wget with the
OpenSSL project's "OpenSSL" library (or with modified versions of it
that use the same license as the "OpenSSL" library), and distribute
the linked executables.  You must obey the GNU General Public License
in all respects for all of the code used other than "OpenSSL".  If you
modify this file, you may extend this exception to your version of the
file, but you are not obligated to do so.  If you do not wish to do
so, delete this exception statement from your version.  */

#include <config.h>

#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifdef HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
#endif
#include <errno.h>

#ifdef WINDOWS
# include <winsock.h>
#else
# include <sys/socket.h>
# include <netinet/in.h>
#ifndef __BEOS__
# include <arpa/inet.h>
#endif
#endif

#ifdef HAVE_PWD_H
# include <pwd.h>
#endif
#include <assert.h>

#include "wget.h"
#include "utils.h"
#include "init.h"
#include "host.h"
#include "recur.h"
#include "netrc.h"
#include "cookies.h"		/* for cookie_jar_delete */
#include "progress.h"

#ifndef errno
extern int errno;
#endif

extern struct cookie_jar *wget_cookie_jar;

/* We want tilde expansion enabled only when reading `.wgetrc' lines;
   otherwise, it will be performed by the shell.  This variable will
   be set by the wgetrc-reading function.  */

static int enable_tilde_expansion;


#define CMD_DECLARE(func) static int func \
  PARAMS ((const char *, const char *, void *))

CMD_DECLARE (cmd_boolean);
CMD_DECLARE (cmd_bytes);
CMD_DECLARE (cmd_directory_vector);
CMD_DECLARE (cmd_lockable_boolean);
CMD_DECLARE (cmd_number);
CMD_DECLARE (cmd_number_inf);
CMD_DECLARE (cmd_string);
CMD_DECLARE (cmd_file);
CMD_DECLARE (cmd_directory);
CMD_DECLARE (cmd_time);
CMD_DECLARE (cmd_vector);

CMD_DECLARE (cmd_spec_dirstruct);
CMD_DECLARE (cmd_spec_header);
CMD_DECLARE (cmd_spec_htmlify);
CMD_DECLARE (cmd_spec_mirror);
CMD_DECLARE (cmd_spec_progress);
CMD_DECLARE (cmd_spec_recursive);
CMD_DECLARE (cmd_spec_restrict_file_names);
CMD_DECLARE (cmd_spec_timeout);
CMD_DECLARE (cmd_spec_useragent);

/* List of recognized commands, each consisting of name, closure and function.
   When adding a new command, simply add it to the list, but be sure to keep the
   list sorted alphabetically, as findcmd() depends on it.  Also, be sure to add
   any entries that allocate memory (e.g. cmd_string and cmd_vector guys) to the
   cleanup() function below. */
static struct {
  char *name;
  void *closure;
  int (*action) PARAMS ((const char *, const char *, void *));
} commands[] = {
  { "accept",		&opt.accepts,		cmd_vector },
  { "addhostdir",	&opt.add_hostdir,	cmd_boolean },
  { "alwaysrest",	&opt.always_rest,	cmd_boolean }, /* deprecated */
  { "background",	&opt.background,	cmd_boolean },
  { "backupconverted",	&opt.backup_converted,	cmd_boolean },
  { "backups",		&opt.backups,		cmd_number },
  { "base",		&opt.base_href,		cmd_string },
  { "bindaddress",	&opt.bind_address,	cmd_string },
  { "cache",		&opt.allow_cache,	cmd_boolean },
  { "connecttimeout",	&opt.connect_timeout,	cmd_time },
  { "continue",		&opt.always_rest,	cmd_boolean },
  { "convertlinks",	&opt.convert_links,	cmd_boolean },
  { "cookies",		&opt.cookies,		cmd_boolean },
  { "cutdirs",		&opt.cut_dirs,		cmd_number },
#ifdef DEBUG
  { "debug",		&opt.debug,		cmd_boolean },
#endif
  { "deleteafter",	&opt.delete_after,	cmd_boolean },
  { "dirprefix",	&opt.dir_prefix,	cmd_directory },
  { "dirstruct",	NULL,			cmd_spec_dirstruct },
  { "dnscache",		&opt.dns_cache,		cmd_boolean },
  { "dnstimeout",	&opt.dns_timeout,	cmd_time },
  { "domains",		&opt.domains,		cmd_vector },
  { "dotbytes",		&opt.dot_bytes,		cmd_bytes },
  { "dotsinline",	&opt.dots_in_line,	cmd_number },
  { "dotspacing",	&opt.dot_spacing,	cmd_number },
  { "dotstyle",		&opt.dot_style,		cmd_string },
#ifdef HAVE_SSL
  { "egdfile",		&opt.sslegdsock,	cmd_file },
#endif
  { "excludedirectories", &opt.excludes,	cmd_directory_vector },
  { "excludedomains",	&opt.exclude_domains,	cmd_vector },
  { "followftp",	&opt.follow_ftp,	cmd_boolean },
  { "followtags",	&opt.follow_tags,	cmd_vector },
  { "forcehtml",	&opt.force_html,	cmd_boolean },
  { "ftpproxy",		&opt.ftp_proxy,		cmd_string },
  { "glob",		&opt.ftp_glob,		cmd_boolean },
  { "header",		NULL,			cmd_spec_header },
  { "htmlextension",	&opt.html_extension,	cmd_boolean },
  { "htmlify",		NULL,			cmd_spec_htmlify },
  { "httpkeepalive",	&opt.http_keep_alive,	cmd_boolean },
  { "httppasswd",	&opt.http_passwd,	cmd_string },
  { "httpproxy",	&opt.http_proxy,	cmd_string },
  { "httpsproxy",	&opt.https_proxy,	cmd_string },
  { "httpuser",		&opt.http_user,		cmd_string },
  { "ignorelength",	&opt.ignore_length,	cmd_boolean },
  { "ignoretags",	&opt.ignore_tags,	cmd_vector },
  { "includedirectories", &opt.includes,	cmd_directory_vector },
  { "input",		&opt.input_filename,	cmd_file },
  { "killlonger",	&opt.kill_longer,	cmd_boolean },
  { "limitrate",	&opt.limit_rate,	cmd_bytes },
  { "loadcookies",	&opt.cookies_input,	cmd_file },
  { "logfile",		&opt.lfilename,		cmd_file },
  { "login",		&opt.ftp_acc,		cmd_string },
  { "mirror",		NULL,			cmd_spec_mirror },
  { "netrc",		&opt.netrc,		cmd_boolean },
  { "noclobber",	&opt.noclobber,		cmd_boolean },
  { "noparent",		&opt.no_parent,		cmd_boolean },
  { "noproxy",		&opt.no_proxy,		cmd_vector },
  { "numtries",		&opt.ntry,		cmd_number_inf },/* deprecated*/
  { "outputdocument",	&opt.output_document,	cmd_file },
  { "pagerequisites",	&opt.page_requisites,	cmd_boolean },
  { "passiveftp",	&opt.ftp_pasv,		cmd_lockable_boolean },
  { "passwd",		&opt.ftp_pass,		cmd_string },
  { "postdata",		&opt.post_data,		cmd_string },
  { "postfile",		&opt.post_file_name,	cmd_file },
  { "progress",		&opt.progress_type,	cmd_spec_progress },
  { "proxypasswd",	&opt.proxy_passwd,	cmd_string },
  { "proxyuser",	&opt.proxy_user,	cmd_string },
  { "quiet",		&opt.quiet,		cmd_boolean },
  { "quota",		&opt.quota,		cmd_bytes },
  { "randomwait",	&opt.random_wait,	cmd_boolean },
  { "readtimeout",	&opt.read_timeout,	cmd_time },
  { "reclevel",		&opt.reclevel,		cmd_number_inf },
  { "recursive",	NULL,			cmd_spec_recursive },
  { "referer",		&opt.referer,		cmd_string },
  { "reject",		&opt.rejects,		cmd_vector },
  { "relativeonly",	&opt.relative_only,	cmd_boolean },
  { "removelisting",	&opt.remove_listing,	cmd_boolean },
  { "restrictfilenames", NULL,			cmd_spec_restrict_file_names },
  { "retrsymlinks",	&opt.retr_symlinks,	cmd_boolean },
  { "retryconnrefused",	&opt.retry_connrefused,	cmd_boolean },
  { "robots",		&opt.use_robots,	cmd_boolean },
  { "savecookies",	&opt.cookies_output,	cmd_file },
  { "saveheaders",	&opt.save_headers,	cmd_boolean },
  { "serverresponse",	&opt.server_response,	cmd_boolean },
  { "spanhosts",	&opt.spanhost,		cmd_boolean },
  { "spider",		&opt.spider,		cmd_boolean },
#ifdef HAVE_SSL
  { "sslcadir",		&opt.sslcadir,		cmd_directory },
  { "sslcafile",	&opt.sslcafile,		cmd_file },
  { "sslcertfile",	&opt.sslcertfile,	cmd_file },
  { "sslcertkey",	&opt.sslcertkey,	cmd_file },
  { "sslcerttype",	&opt.sslcerttype,	cmd_number },
  { "sslcheckcert",	&opt.sslcheckcert,	cmd_number },
  { "sslprotocol",	&opt.sslprotocol,	cmd_number },
#endif /* HAVE_SSL */
  { "strictcomments",	&opt.strict_comments,	cmd_boolean },
  { "timeout",		NULL,			cmd_spec_timeout },
  { "timestamping",	&opt.timestamping,	cmd_boolean },
  { "tries",		&opt.ntry,		cmd_number_inf },
  { "useproxy",		&opt.use_proxy,		cmd_boolean },
  { "useragent",	NULL,			cmd_spec_useragent },
  { "verbose",		&opt.verbose,		cmd_boolean },
  { "wait",		&opt.wait,		cmd_time },
  { "waitretry",	&opt.waitretry,		cmd_time }
};

/* Look up COM in the commands[] array and return its index.  If COM
   is not found, -1 is returned.  This function uses binary search.  */

static int
findcmd (const char *com)
{
  int lo = 0, hi = countof (commands) - 1;

  while (lo <= hi)
    {
      int mid = (lo + hi) >> 1;
      int cmp = strcasecmp (com, commands[mid].name);
      if (cmp < 0)
	hi = mid - 1;
      else if (cmp > 0)
	lo = mid + 1;
      else
	return mid;
    }
  return -1;
}

/* Reset the variables to default values.  */
static void
defaults (void)
{
  char *tmp;

  /* Most of the default values are 0.  Just reset everything, and
     fill in the non-zero values.  Note that initializing pointers to
     NULL this way is technically illegal, but porting Wget to a
     machine where NULL is not all-zero bit pattern will be the least
     of the implementors' worries.  */
  memset (&opt, 0, sizeof (opt));

  opt.cookies = 1;

  opt.verbose = -1;
  opt.ntry = 20;
  opt.reclevel = 5;
  opt.add_hostdir = 1;
  opt.ftp_acc  = xstrdup ("anonymous");
  opt.ftp_pass = xstrdup ("-wget@");
  opt.netrc = 1;
  opt.ftp_glob = 1;
  opt.htmlify = 1;
  opt.http_keep_alive = 1;
  opt.use_proxy = 1;
  tmp = getenv ("no_proxy");
  if (tmp)
    opt.no_proxy = sepstring (tmp);
  opt.allow_cache = 1;

  opt.read_timeout = 900;
  opt.use_robots = 1;

  opt.remove_listing = 1;

  opt.dot_bytes = 1024;
  opt.dot_spacing = 10;
  opt.dots_in_line = 50;

  opt.dns_cache = 1;

  /* The default for file name restriction defaults to the OS type. */
#if !defined(WINDOWS) && !defined(__CYGWIN__)
  opt.restrict_files_os = restrict_unix;
#else
  opt.restrict_files_os = restrict_windows;
#endif
  opt.restrict_files_ctrl = 1;
}

/* Return the user's home directory (strdup-ed), or NULL if none is
   found.  */
char *
home_dir (void)
{
  char *home = getenv ("HOME");

  if (!home)
    {
#ifndef WINDOWS
      /* If HOME is not defined, try getting it from the password
         file.  */
      struct passwd *pwd = getpwuid (getuid ());
      if (!pwd || !pwd->pw_dir)
	return NULL;
      home = pwd->pw_dir;
#else  /* WINDOWS */
      home = "C:\\";
      /* #### Maybe I should grab home_dir from registry, but the best
	 that I could get from there is user's Start menu.  It sucks!  */
#endif /* WINDOWS */
    }

  return home ? xstrdup (home) : NULL;
}

/* Return the path to the user's .wgetrc.  This is either the value of
   `WGETRC' environment variable, or `$HOME/.wgetrc'.

   If the `WGETRC' variable exists but the file does not exist, the
   function will exit().  */
static char *
wgetrc_file_name (void)
{
  char *env, *home;
  char *file = NULL;

  /* Try the environment.  */
  env = getenv ("WGETRC");
  if (env && *env)
    {
      if (!file_exists_p (env))
	{
	  fprintf (stderr, "%s: %s: %s.\n", exec_name, env, strerror (errno));
	  exit (1);
	}
      return xstrdup (env);
    }

#ifndef WINDOWS
  /* If that failed, try $HOME/.wgetrc.  */
  home = home_dir ();
  if (home)
    {
      file = (char *)xmalloc (strlen (home) + 1 + strlen (".wgetrc") + 1);
      sprintf (file, "%s/.wgetrc", home);
    }
  FREE_MAYBE (home);
#else  /* WINDOWS */
  /* Under Windows, "home" is (for the purposes of this function) the
     directory where `wget.exe' resides, and `wget.ini' will be used
     as file name.  SYSTEM_WGETRC should not be defined under WINDOWS.

     It is not as trivial as I assumed, because on 95 argv[0] is full
     path, but on NT you get what you typed in command line.  --dbudor */
  home = ws_mypath ();
  if (home)
    {
      file = (char *)xmalloc (strlen (home) + strlen ("wget.ini") + 1);
      sprintf (file, "%swget.ini", home);
    }
#endif /* WINDOWS */

  if (!file)
    return NULL;
  if (!file_exists_p (file))
    {
      xfree (file);
      return NULL;
    }
  return file;
}

static int parse_line PARAMS ((const char *, char **, char **, int *));
static int setval_internal PARAMS ((int, const char *, const char *));

/* Initialize variables from a wgetrc file.  */

static void
run_wgetrc (const char *file)
{
  FILE *fp;
  char *line;
  int ln;

  fp = fopen (file, "rb");
  if (!fp)
    {
      fprintf (stderr, _("%s: Cannot read %s (%s).\n"), exec_name,
	       file, strerror (errno));
      return;
    }
  enable_tilde_expansion = 1;
  ln = 1;
  while ((line = read_whole_line (fp)))
    {
      char *com, *val;
      int comind, status;

      /* Parse the line.  */
      status = parse_line (line, &com, &val, &comind);
      xfree (line);
      /* If everything is OK, set the value.  */
      if (status == 1)
	{
	  if (!setval_internal (comind, com, val))
	    fprintf (stderr, _("%s: Error in %s at line %d.\n"), exec_name,
		     file, ln);
	  xfree (com);
	  xfree (val);
	}
      else if (status == 0)
	fprintf (stderr, _("%s: Error in %s at line %d.\n"), exec_name,
		 file, ln);
      ++ln;
    }
  enable_tilde_expansion = 0;
  fclose (fp);
}

/* Initialize the defaults and run the system wgetrc and user's own
   wgetrc.  */
void
initialize (void)
{
  char *file;

  /* Load the hard-coded defaults.  */
  defaults ();

  /* If SYSTEM_WGETRC is defined, use it.  */
#ifdef SYSTEM_WGETRC
  if (file_exists_p (SYSTEM_WGETRC))
    run_wgetrc (SYSTEM_WGETRC);
#endif
  /* Override it with your own, if one exists.  */
  file = wgetrc_file_name ();
  if (!file)
    return;
  /* #### We should canonicalize `file' and SYSTEM_WGETRC with
     something like realpath() before comparing them with `strcmp'  */
#ifdef SYSTEM_WGETRC
  if (!strcmp (file, SYSTEM_WGETRC))
    {
      fprintf (stderr, _("\
%s: Warning: Both system and user wgetrc point to `%s'.\n"),
	       exec_name, file);
    }
  else
#endif
    run_wgetrc (file);
  xfree (file);
  return;
}

/* Remove dashes and underscores from S, modifying S in the
   process. */

static void
dehyphen (char *s)
{
  char *t = s;			/* t - tortoise */
  char *h = s;			/* h - hare     */
  while (*h)
    if (*h == '_' || *h == '-')
      ++h;
    else
      *t++ = *h++;
  *t = '\0';
}

/* Parse the line pointed by line, with the syntax:
   <sp>* command <sp>* = <sp>* value <newline>
   Uses malloc to allocate space for command and value.
   If the line is invalid, data is freed and 0 is returned.

   Return values:
    1 - success
    0 - failure
   -1 - empty */

static int
parse_line (const char *line, char **com, char **val, int *comind)
{
  const char *p;
  const char *end = line + strlen (line);
  const char *cmdstart, *cmdend;
  const char *valstart, *valend;

  char *cmdcopy;
  int ind;

  /* Skip leading and trailing whitespace.  */
  while (*line && ISSPACE (*line))
    ++line;
  while (end > line && ISSPACE (end[-1]))
    --end;

  /* Skip empty lines and comments.  */
  if (!*line || *line == '#')
    return -1;

  p = line;

  cmdstart = p;
  while (p < end && (ISALPHA (*p) || *p == '_' || *p == '-'))
    ++p;
  cmdend = p;

  /* Skip '=', as well as any space before or after it. */
  while (p < end && ISSPACE (*p))
    ++p;
  if (p == end || *p != '=')
    return 0;
  ++p;
  while (p < end && ISSPACE (*p))
    ++p;

  valstart = p;
  valend   = end;

  /* The line now known to be syntactically correct.  Check whether
     the command is valid.  */
  BOUNDED_TO_ALLOCA (cmdstart, cmdend, cmdcopy);
  dehyphen (cmdcopy);
  ind = findcmd (cmdcopy);
  if (ind == -1)
    return 0;

  /* The command is valid.  Now fill in the values and report success
     to the caller.  */
  *comind = ind;
  *com = strdupdelim (cmdstart, cmdend);
  *val = strdupdelim (valstart, valend);
  return 1;
}

/* Run commands[comind].action. */

static int
setval_internal (int comind, const char *com, const char *val)
{
  assert (0 <= comind && comind < countof (commands));
  return ((*commands[comind].action) (com, val, commands[comind].closure));
}

/* Run command COM with value VAL.  If running the command produces an
   error, report the error and exit.

   This is intended to be called from main() with commands not
   provided by the user, therefore it aborts when an unknown command
   is encountered.  Once the COMIND's are exported to init.h, this
   function will be changed to accept COMIND directly.  */

void
setoptval (const char *com, const char *val)
{
  int comind = findcmd (com);
  assert (comind != -1);
  if (!setval_internal (comind, com, val))
    exit (2);
}

void
run_command (const char *opt)
{
  char *com, *val;
  int comind;
  int status = parse_line (opt, &com, &val, &comind);
  if (status == 1)
    {
      if (!setval_internal (comind, com, val))
	exit (2);
      xfree (com);
      xfree (val);
    }
  else if (status == 0)
    {
      fprintf (stderr, "Invalid command `%s'\n", opt);
      exit (2);
    }
}

/* Generic helper functions, for use with `commands'. */

static int myatoi PARAMS ((const char *s));

/* Store the boolean value from VAL to CLOSURE.  COM is ignored,
   except for error messages.  */
static int
cmd_boolean (const char *com, const char *val, void *closure)
{
  int bool_value;
  const char *v = val;
#define LC(x) TOLOWER(x)

  if ((LC(v[0]) == 'o' && LC(v[1]) == 'n' && !v[2])
      ||
      (LC(v[0]) == 'y' && LC(v[1]) == 'e' && LC(v[2]) == 's' && !v[3])
      ||
      (v[0] == '1' && !v[1]))
    /* "on", "yes" and "1" mean true. */
    bool_value = 1;
  else if ((LC(v[0]) == 'o' && LC(v[1]) == 'f' && LC(v[2]) == 'f' && !v[3])
	   ||
	   (LC(v[0]) == 'n' && LC(v[1]) == 'o' && !v[2])
	   ||
	   (v[0] == '0' && !v[1]))
    /* "off", "no" and "0" mean false. */
    bool_value = 0;
  else
    {
      fprintf (stderr, _("%s: %s: Please specify on or off.\n"),
	       exec_name, com);
      return 0;
    }

  *(int *)closure = bool_value;
  return 1;
}

/* Store the lockable_boolean {2, 1, 0, -1} value from VAL to CLOSURE.  COM is
   ignored, except for error messages.  Values 2 and -1 indicate that once
   defined, the value may not be changed by successive wgetrc files or
   command-line arguments.

   Values: 2 - Enable a particular option for good ("always")
           1 - Enable an option ("on")
           0 - Disable an option ("off")
          -1 - Disable an option for good ("never") */
static int
cmd_lockable_boolean (const char *com, const char *val, void *closure)
{
  int lockable_boolean_value;

  /*
   * If a config file said "always" or "never", don't allow command line
   * arguments to override the config file.
   */
  if (*(int *)closure == -1 || *(int *)closure == 2)
    return 1;

  if (!strcasecmp (val, "always") || !strcmp (val, "2"))
    lockable_boolean_value = 2;
  else if (!strcasecmp (val, "on")
	   || !strcasecmp (val, "yes")
	   || !strcmp (val, "1"))
    lockable_boolean_value = 1;
  else if (!strcasecmp (val, "off")
	   || !strcasecmp (val, "no")
	   || !strcmp (val, "0"))
    lockable_boolean_value = 0;
  else if (!strcasecmp (val, "never") || !strcmp (val, "-1"))
    lockable_boolean_value = -1;
  else
    {
      fprintf (stderr, _("%s: %s: Please specify always, on, off, "
			 "or never.\n"),
	       exec_name, com);
      return 0;
    }

  *(int *)closure = lockable_boolean_value;
  return 1;
}

/* Set the non-negative integer value from VAL to CLOSURE.  With
   incorrect specification, the number remains unchanged.  */
static int
cmd_number (const char *com, const char *val, void *closure)
{
  int num = myatoi (val);

  if (num == -1)
    {
      fprintf (stderr, _("%s: %s: Invalid specification `%s'.\n"),
	       exec_name, com, val);
      return 0;
    }
  *(int *)closure = num;
  return 1;
}

/* Similar to cmd_number(), only accepts `inf' as a synonym for 0.  */
static int
cmd_number_inf (const char *com, const char *val, void *closure)
{
  if (!strcasecmp (val, "inf"))
    {
      *(int *)closure = 0;
      return 1;
    }
  return cmd_number (com, val, closure);
}

/* Copy (strdup) the string at COM to a new location and place a
   pointer to *CLOSURE.  */
static int
cmd_string (const char *com, const char *val, void *closure)
{
  char **pstring = (char **)closure;

  FREE_MAYBE (*pstring);
  *pstring = xstrdup (val);
  return 1;
}

#ifndef WINDOWS
# define ISSEP(c) ((c) == '/')
#else
# define ISSEP(c) ((c) == '/' || (c) == '\\')
#endif

/* Like the above, but handles tilde-expansion when reading a user's
   `.wgetrc'.  In that case, and if VAL begins with `~', the tilde
   gets expanded to the user's home directory.  */
static int
cmd_file (const char *com, const char *val, void *closure)
{
  char **pstring = (char **)closure;

  FREE_MAYBE (*pstring);

  /* #### If VAL is empty, perhaps should set *CLOSURE to NULL.  */

  if (!enable_tilde_expansion || !(*val == '~' && ISSEP (val[1])))
    {
    noexpand:
      *pstring = xstrdup (val);
    }
  else
    {
      char *result;
      int homelen;
      char *home = home_dir ();
      if (!home)
	goto noexpand;

      homelen = strlen (home);
      while (homelen && ISSEP (home[homelen - 1]))
	home[--homelen] = '\0';

      /* Skip the leading "~/". */
      for (++val; ISSEP (*val); val++)
	;

      result = xmalloc (homelen + 1 + strlen (val) + 1);
      memcpy (result, home, homelen);
      result[homelen] = '/';
      strcpy (result + homelen + 1, val);

      *pstring = result;
    }

#ifdef WINDOWS
  /* Convert "\" to "/". */
  {
    char *s;
    for (s = *pstring; *s; s++)
      if (*s == '\\')
	*s = '/';
  }
#endif
  return 1;
}

/* Like cmd_file, but strips trailing '/' characters.  */
static int
cmd_directory (const char *com, const char *val, void *closure)
{
  char *s, *t;

  /* Call cmd_file() for tilde expansion and separator
     canonicalization (backslash -> slash under Windows).  These
     things should perhaps be in a separate function.  */
  if (!cmd_file (com, val, closure))
    return 0;

  s = *(char **)closure;
  t = s + strlen (s);
  while (t > s && *--t == '/')
    *t = '\0';

  return 1;
}

/* Merge the vector (array of strings separated with `,') in COM with
   the vector (NULL-terminated array of strings) pointed to by
   CLOSURE.  */
static int
cmd_vector (const char *com, const char *val, void *closure)
{
  char ***pvec = (char ***)closure;

  if (*val)
    *pvec = merge_vecs (*pvec, sepstring (val));
  else
    {
      free_vec (*pvec);
      *pvec = NULL;
    }
  return 1;
}

static int
cmd_directory_vector (const char *com, const char *val, void *closure)
{
  char ***pvec = (char ***)closure;

  if (*val)
    {
      /* Strip the trailing slashes from directories.  */
      char **t, **seps;

      seps = sepstring (val);
      for (t = seps; t && *t; t++)
	{
	  int len = strlen (*t);
	  /* Skip degenerate case of root directory.  */
	  if (len > 1)
	    {
	      if ((*t)[len - 1] == '/')
		(*t)[len - 1] = '\0';
	    }
	}
      *pvec = merge_vecs (*pvec, seps);
    }
  else
    {
      free_vec (*pvec);
      *pvec = NULL;
    }
  return 1;
}

/* Poor man's atof: handles only <digits>.<digits>.  Returns 1 on
   success, 0 on failure.  In case of success, stores its result to
   *DEST.  */

static int
simple_atof (const char *beg, const char *end, double *dest)
{
  double result = 0;

  int seen_dot = 0;
  int seen_digit = 0;
  double divider = 1;

  const char *p = beg;

  while (p < end)
    {
      char ch = *p++;
      if (ISDIGIT (ch))
	{
	  if (!seen_dot)
	    result = (10 * result) + (ch - '0');
	  else
	    result += (ch - '0') / (divider *= 10);
	  seen_digit = 1;
	}
      else if (ch == '.')
	{
	  if (!seen_dot)
	    seen_dot = 1;
	  else
	    return 0;
	}
    }
  if (!seen_digit)
    return 0;

  *dest = result;
  return 1;
}

/* Parse VAL as a number and set its value to CLOSURE (which should
   point to a long int).

   By default, the value is assumed to be in bytes.  If "K", "M", or
   "G" are appended, the value is multiplied with 1<<10, 1<<20, or
   1<<30, respectively.  Floating point values are allowed and are
   cast to integer before use.  The idea is to be able to use things
   like 1.5k instead of "1536".

   The string "inf" is returned as 0.

   In case of error, 0 is returned and memory pointed to by CLOSURE
   remains unmodified.  */

static int
cmd_bytes (const char *com, const char *val, void *closure)
{
  long mult;
  double number;
  const char *end = val + strlen (val);

  /* Check for "inf".  */
  if (0 == strcmp (val, "inf"))
    {
      *(long *)closure = 0;
      return 1;
    }

  /* Strip trailing whitespace.  */
  while (val < end && ISSPACE (end[-1]))
    --end;

  if (val == end)
    {
    err:
      fprintf (stderr, _("%s: Invalid byte value `%s'\n"), com, val);
      return 0;
    }

  switch (TOLOWER (end[-1]))
    {
    case 'k':
      --end, mult = 1L<<10;
      break;
    case 'm':
      --end, mult = 1L<<20;
      break;
    case 'g':
      --end, mult = 1L<<30;
      break;
    default:
      /* Not a recognized suffix: assume it belongs to the number.
	 (If not, atof simple_atof will raise an error.)  */
      mult = 1;
    }

  /* Skip leading and trailing whitespace. */
  while (val < end && ISSPACE (*val))
    ++val;
  while (val < end && ISSPACE (end[-1]))
    --end;
  if (val == end)
    goto err;

  if (!simple_atof (val, end, &number))
    goto err;

  *(long *)closure = (long)(number * mult);
  return 1;
}

/* Store the value of VAL to *OUT.  The value is a time period, by
   default expressed in seconds, but also accepting suffixes "m", "h",
   "d", and "w" for minutes, hours, days, and weeks respectively.  */

static int
cmd_time (const char *com, const char *val, void *closure)
{
  double number, mult;
  const char *end = val + strlen (val);

  /* Strip trailing whitespace.  */
  while (val < end && ISSPACE (end[-1]))
    --end;

  if (val == end)
    {
    err:
      fprintf (stderr, _("%s: Invalid time specification `%s'\n"), com, val);
      return 0;
    }

  switch (TOLOWER (end[-1]))
    {
    case 's':
      --end, mult = 1;		/* seconds */
      break;
    case 'm':
      --end, mult = 60;		/* minutes */
      break;
    case 'h':
      --end, mult = 3600;	/* hours */
      break;
    case 'd':
      --end, mult = 86400.0;	/* days */
      break;
    case 'w':
      --end, mult = 604800.0;	/* weeks */
      break;
    default:
      /* Not a recognized suffix: assume it belongs to the number.
	 (If not, atof simple_atof will raise an error.)  */
      mult = 1;
    }

  /* Skip leading and trailing whitespace. */
  while (val < end && ISSPACE (*val))
    ++val;
  while (val < end && ISSPACE (end[-1]))
    --end;
  if (val == end)
    goto err;

  if (!simple_atof (val, end, &number))
    goto err;

  *(double *)closure = number * mult;
  return 1;
}

/* Specialized helper functions, used by `commands' to handle some
   options specially.  */

static int check_user_specified_header PARAMS ((const char *));

static int
cmd_spec_dirstruct (const char *com, const char *val, void *closure)
{
  if (!cmd_boolean (com, val, &opt.dirstruct))
    return 0;
  /* Since dirstruct behaviour is explicitly changed, no_dirstruct
     must be affected inversely.  */
  if (opt.dirstruct)
    opt.no_dirstruct = 0;
  else
    opt.no_dirstruct = 1;
  return 1;
}

static int
cmd_spec_header (const char *com, const char *val, void *closure)
{
  if (!*val)
    {
      /* Empty header means reset headers.  */
      FREE_MAYBE (opt.user_header);
      opt.user_header = NULL;
    }
  else
    {
      int i;

      if (!check_user_specified_header (val))
	{
	  fprintf (stderr, _("%s: %s: Invalid specification `%s'.\n"),
		   exec_name, com, val);
	  return 0;
	}
      i = opt.user_header ? strlen (opt.user_header) : 0;
      opt.user_header = (char *)xrealloc (opt.user_header, i + strlen (val)
					  + 2 + 1);
      strcpy (opt.user_header + i, val);
      i += strlen (val);
      opt.user_header[i++] = '\r';
      opt.user_header[i++] = '\n';
      opt.user_header[i] = '\0';
    }
  return 1;
}

static int
cmd_spec_htmlify (const char *com, const char *val, void *closure)
{
  int flag = cmd_boolean (com, val, &opt.htmlify);
  if (flag && !opt.htmlify)
    opt.remove_listing = 0;
  return flag;
}

static int
cmd_spec_mirror (const char *com, const char *val, void *closure)
{
  int mirror;

  if (!cmd_boolean (com, val, &mirror))
    return 0;
  if (mirror)
    {
      opt.recursive = 1;
      if (!opt.no_dirstruct)
	opt.dirstruct = 1;
      opt.timestamping = 1;
      opt.reclevel = INFINITE_RECURSION;
      opt.remove_listing = 0;
    }
  return 1;
}

static int
cmd_spec_progress (const char *com, const char *val, void *closure)
{
  if (!valid_progress_implementation_p (val))
    {
      fprintf (stderr, _("%s: %s: Invalid progress type `%s'.\n"),
	       exec_name, com, val);
      return 0;
    }
  FREE_MAYBE (opt.progress_type);

  /* Don't call set_progress_implementation here.  It will be called
     in main() when it becomes clear what the log output is.  */
  opt.progress_type = xstrdup (val);
  return 1;
}

static int
cmd_spec_recursive (const char *com, const char *val, void *closure)
{
  if (!cmd_boolean (com, val, &opt.recursive))
    return 0;
  else
    {
      if (opt.recursive && !opt.no_dirstruct)
	opt.dirstruct = 1;
    }
  return 1;
}

static int
cmd_spec_restrict_file_names (const char *com, const char *val, void *closure)
{
  int restrict_os = opt.restrict_files_os;
  int restrict_ctrl = opt.restrict_files_ctrl;

  const char *end = strchr (val, ',');
  if (!end)
    end = val + strlen (val);

#define VAL_IS(string_literal) BOUNDED_EQUAL (val, end, string_literal)

  if (VAL_IS ("unix"))
    restrict_os = restrict_unix;
  else if (VAL_IS ("windows"))
    restrict_os = restrict_windows;
  else if (VAL_IS ("nocontrol"))
    restrict_ctrl = 0;
  else
    {
    err:
      fprintf (stderr, _("%s: %s: Invalid specification `%s'.\n"),
	       exec_name, com, val);
      return 0;
    }

#undef VAL_IS

  if (*end)
    {
      if (!strcmp (end + 1, "nocontrol"))
	restrict_ctrl = 0;
      else
	goto err;
    }

  opt.restrict_files_os = restrict_os;
  opt.restrict_files_ctrl = restrict_ctrl;
  return 1;
}

/* Set all three timeout values. */

static int
cmd_spec_timeout (const char *com, const char *val, void *closure)
{
  double value;
  if (!cmd_time (com, val, &value))
    return 0;
  opt.read_timeout = value;
  opt.connect_timeout = value;
  opt.dns_timeout = value;
  return 1;
}

static int
cmd_spec_useragent (const char *com, const char *val, void *closure)
{
  /* Just check for empty string and newline, so we don't throw total
     junk to the server.  */
  if (!*val || strchr (val, '\n'))
    {
      fprintf (stderr, _("%s: %s: Invalid specification `%s'.\n"),
	       exec_name, com, val);
      return 0;
    }
  opt.useragent = xstrdup (val);
  return 1;
}

/* Miscellaneous useful routines.  */

/* Return the integer value of a positive integer written in S, or -1
   if an error was encountered.  */
static int
myatoi (const char *s)
{
  int res;
  const char *orig = s;

  for (res = 0; *s && ISDIGIT (*s); s++)
    res = 10 * res + (*s - '0');
  if (*s || orig == s)
    return -1;
  else
    return res;
}

static int
check_user_specified_header (const char *s)
{
  const char *p;

  for (p = s; *p && *p != ':' && !ISSPACE (*p); p++);
  /* The header MUST contain `:' preceded by at least one
     non-whitespace character.  */
  if (*p != ':' || p == s)
    return 0;
  /* The header MUST NOT contain newlines.  */
  if (strchr (s, '\n'))
    return 0;
  return 1;
}

void cleanup_html_url PARAMS ((void));
void res_cleanup PARAMS ((void));
void downloaded_files_free PARAMS ((void));
void http_cleanup PARAMS ((void));


/* Free the memory allocated by global variables.  */
void
cleanup (void)
{
  /* Free external resources, close files, etc. */

  if (opt.dfp)
    fclose (opt.dfp);

  /* We're exiting anyway so there's no real need to call free()
     hundreds of times.  Skipping the frees will make Wget exit
     faster.

     However, when detecting leaks, it's crucial to free() everything
     because then you can find the real leaks, i.e. the allocated
     memory which grows with the size of the program.  */

#ifdef DEBUG_MALLOC
  recursive_cleanup ();
  res_cleanup ();
  http_cleanup ();
  cleanup_html_url ();
  downloaded_files_free ();
  host_cleanup ();
  cookie_jar_delete (wget_cookie_jar);

  {
    extern acc_t *netrc_list;
    free_netrc (netrc_list);
  }
  FREE_MAYBE (opt.lfilename);
  FREE_MAYBE (opt.dir_prefix);
  FREE_MAYBE (opt.input_filename);
  FREE_MAYBE (opt.output_document);
  free_vec (opt.accepts);
  free_vec (opt.rejects);
  free_vec (opt.excludes);
  free_vec (opt.includes);
  free_vec (opt.domains);
  free_vec (opt.follow_tags);
  free_vec (opt.ignore_tags);
  FREE_MAYBE (opt.progress_type);
  xfree (opt.ftp_acc);
  FREE_MAYBE (opt.ftp_pass);
  FREE_MAYBE (opt.ftp_proxy);
  FREE_MAYBE (opt.https_proxy);
  FREE_MAYBE (opt.http_proxy);
  free_vec (opt.no_proxy);
  FREE_MAYBE (opt.useragent);
  FREE_MAYBE (opt.referer);
  FREE_MAYBE (opt.http_user);
  FREE_MAYBE (opt.http_passwd);
  FREE_MAYBE (opt.user_header);
#ifdef HAVE_SSL
  FREE_MAYBE (opt.sslcertkey);
  FREE_MAYBE (opt.sslcertfile);
#endif /* HAVE_SSL */
  FREE_MAYBE (opt.bind_address);
  FREE_MAYBE (opt.cookies_input);
  FREE_MAYBE (opt.cookies_output);
#endif
}