ftp-ls.c

wget (command line browser) source code

/* Parsing FTP `ls' output.
   Copyright (C) 1995, 1996, 1997, 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 <stdlib.h>
#ifdef HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <sys/types.h>
#include <errno.h>

#include "wget.h"
#include "utils.h"
#include "ftp.h"
#include "url.h"

/* Converts symbolic permissions to number-style ones, e.g. string
   rwxr-xr-x to 755.  For now, it knows nothing of
   setuid/setgid/sticky.  ACLs are ignored.  */
static int
symperms (const char *s)
{
  int perms = 0, i;

  if (strlen (s) < 9)
    return 0;
  for (i = 0; i < 3; i++, s += 3)
    {
      perms <<= 3;
      perms += (((s[0] == 'r') << 2) + ((s[1] == 'w') << 1) +
		(s[2] == 'x' || s[2] == 's'));
    }
  return perms;
}


/* Cleans a line of text so that it can be consistently parsed. Destroys
   <CR> and <LF> in case that thay occur at the end of the line and
   replaces all <TAB> character with <SPACE>. Returns the length of the
   modified line. */
static int
clean_line(char *line)
{
  int len = strlen (line);
  if (!len) return 0; 
  if (line[len - 1] == '\n')
    line[--len] = '\0';
  if (line[len - 1] == '\r')
    line[--len] = '\0';
  for ( ; *line ; line++ ) if (*line == '\t') *line = ' '; 
  return len;
}

/* Convert the Un*x-ish style directory listing stored in FILE to a
   linked list of fileinfo (system-independent) entries.  The contents
   of FILE are considered to be produced by the standard Unix `ls -la'
   output (whatever that might be).  BSD (no group) and SYSV (with
   group) listings are handled.

   The time stamps are stored in a separate variable, time_t
   compatible (I hope).  The timezones are ignored.  */
static struct fileinfo *
ftp_parse_unix_ls (const char *file, int ignore_perms)
{
  FILE *fp;
  static const char *months[] = {
    "Jan", "Feb", "Mar", "Apr", "May", "Jun",
    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
  };
  int next, len, i, error, ignore;
  int year, month, day;		/* for time analysis */
  int hour, min, sec;
  struct tm timestruct, *tnow;
  time_t timenow;

  char *line, *tok;		/* tokenizer */
  struct fileinfo *dir, *l, cur; /* list creation */

  fp = fopen (file, "rb");
  if (!fp)
    {
      logprintf (LOG_NOTQUIET, "%s: %s\n", file, strerror (errno));
      return NULL;
    }
  dir = l = NULL;

  /* Line loop to end of file: */
  while ((line = read_whole_line (fp)))
    {
      len = clean_line (line);
      /* Skip if total...  */
      if (!strncasecmp (line, "total", 5))
	{
	  xfree (line);
	  continue;
	}
      /* Get the first token (permissions).  */
      tok = strtok (line, " ");
      if (!tok)
	{
	  xfree (line);
	  continue;
	}

      cur.name = NULL;
      cur.linkto = NULL;

      /* Decide whether we deal with a file or a directory.  */
      switch (*tok)
	{
	case '-':
	  cur.type = FT_PLAINFILE;
	  DEBUGP (("PLAINFILE; "));
	  break;
	case 'd':
	  cur.type = FT_DIRECTORY;
	  DEBUGP (("DIRECTORY; "));
	  break;
	case 'l':
	  cur.type = FT_SYMLINK;
	  DEBUGP (("SYMLINK; "));
	  break;
	default:
	  cur.type = FT_UNKNOWN;
	  DEBUGP (("UNKNOWN; "));
	  break;
	}

      if (ignore_perms)
	{
 	  switch (cur.type)
 	    {
 	    case FT_PLAINFILE:
 	      cur.perms = 0644;
 	      break;
 	    case FT_DIRECTORY:
 	      cur.perms = 0755;
 	      break;
 	    default:
 	      /*cur.perms = 1023;*/	/* #### What is this?  --hniksic */
	      cur.perms = 0644;
 	    }
 	  DEBUGP (("implicit perms %0o; ", cur.perms));
	}
       else
         {
	   cur.perms = symperms (tok + 1);
	   DEBUGP (("perms %0o; ", cur.perms));
	 }

      error = ignore = 0;       /* Erroneous and ignoring entries are
				   treated equally for now.  */
      year = hour = min = sec = 0; /* Silence the compiler.  */
      month = day = 0;
      next = -1;
      /* While there are tokens on the line, parse them.  Next is the
	 number of tokens left until the filename.

	 Use the month-name token as the "anchor" (the place where the
	 position wrt the file name is "known").  When a month name is
	 encountered, `next' is set to 5.  Also, the preceding
	 characters are parsed to get the file size.

	 This tactic is quite dubious when it comes to
	 internationalization issues (non-English month names), but it
	 works for now.  */
      while ((tok = strtok (NULL, " ")))
	{
	  --next;
	  if (next < 0)		/* a month name was not encountered */
	    {
	      for (i = 0; i < 12; i++)
		if (!strcmp (tok, months[i]))
		  break;
	      /* If we got a month, it means the token before it is the
		 size, and the filename is three tokens away.  */
	      if (i != 12)
		{
		  char *t = tok - 2;
		  long mul = 1;

		  for (cur.size = 0; t > line && ISDIGIT (*t); mul *= 10, t--)
		    cur.size += mul * (*t - '0');
		  if (t == line)
		    {
		      /* Something is seriously wrong.  */
		      error = 1;
		      break;
		    }
		  month = i;
		  next = 5;
		  DEBUGP (("month: %s; ", months[month]));
		}
	    }
	  else if (next == 4)	/* days */
	    {
	      if (tok[1])	/* two-digit... */
		day = 10 * (*tok - '0') + tok[1] - '0';
	      else		/* ...or one-digit */
		day = *tok - '0';
	      DEBUGP (("day: %d; ", day));
	    }
	  else if (next == 3)
	    {
	      /* This ought to be either the time, or the year.  Let's
		 be flexible!

		 If we have a number x, it's a year.  If we have x:y,
		 it's hours and minutes.  If we have x:y:z, z are
		 seconds.  */
	      year = 0;
	      min = hour = sec = 0;
	      /* We must deal with digits.  */
	      if (ISDIGIT (*tok))
		{
		  /* Suppose it's year.  */
		  for (; ISDIGIT (*tok); tok++)
		    year = (*tok - '0') + 10 * year;
		  if (*tok == ':')
		    {
		      /* This means these were hours!  */
		      hour = year;
		      year = 0;
		      ++tok;
		      /* Get the minutes...  */
		      for (; ISDIGIT (*tok); tok++)
			min = (*tok - '0') + 10 * min;
		      if (*tok == ':')
			{
			  /* ...and the seconds.  */
			  ++tok;
			  for (; ISDIGIT (*tok); tok++)
			    sec = (*tok - '0') + 10 * sec;
			}
		    }
		}
	      if (year)
		DEBUGP (("year: %d (no tm); ", year));
	      else
		DEBUGP (("time: %02d:%02d:%02d (no yr); ", hour, min, sec));
	    }
	  else if (next == 2)    /* The file name */
	    {
	      int fnlen;
	      char *p;

	      /* Since the file name may contain a SPC, it is possible
		 for strtok to handle it wrong.  */
	      fnlen = strlen (tok);
	      if (fnlen < len - (tok - line))
		{
		  /* So we have a SPC in the file name.  Restore the
		     original.  */
		  tok[fnlen] = ' ';
		  /* If the file is a symbolic link, it should have a
		     ` -> ' somewhere.  */
		  if (cur.type == FT_SYMLINK)
		    {
		      p = strstr (tok, " -> ");
		      if (!p)
			{
			  error = 1;
			  break;
			}
		      cur.linkto = xstrdup (p + 4);
		      DEBUGP (("link to: %s\n", cur.linkto));
		      /* And separate it from the file name.  */
		      *p = '\0';
		    }
		}
	      /* If we have the filename, add it to the list of files or
		 directories.  */
	      /* "." and ".." are an exception!  */
	      if (!strcmp (tok, ".") || !strcmp (tok, ".."))
		{
		  DEBUGP (("\nIgnoring `.' and `..'; "));
		  ignore = 1;
		  break;
		}
	      /* Some FTP sites choose to have ls -F as their default
		 LIST output, which marks the symlinks with a trailing
		 `@', directory names with a trailing `/' and
		 executables with a trailing `*'.  This is no problem
		 unless encountering a symbolic link ending with `@',
		 or an executable ending with `*' on a server without
		 default -F output.  I believe these cases are very
		 rare.  */
	      fnlen = strlen (tok); /* re-calculate `fnlen' */
	      cur.name = (char *)xmalloc (fnlen + 1);
	      memcpy (cur.name, tok, fnlen + 1);
	      if (fnlen)
		{
		  if (cur.type == FT_DIRECTORY && cur.name[fnlen - 1] == '/')
		    {
		      cur.name[fnlen - 1] = '\0';
		      DEBUGP (("trailing `/' on dir.\n"));
		    }
		  else if (cur.type == FT_SYMLINK && cur.name[fnlen - 1] == '@')
		    {
		      cur.name[fnlen - 1] = '\0';
		      DEBUGP (("trailing `@' on link.\n"));
		    }
		  else if (cur.type == FT_PLAINFILE
			   && (cur.perms & 0111)
			   && cur.name[fnlen - 1] == '*')
		    {
		      cur.name[fnlen - 1] = '\0';
		      DEBUGP (("trailing `*' on exec.\n"));
		    }
		} /* if (fnlen) */
	      else
		error = 1;
	      break;
	    }
	  else
	    abort ();
	} /* while */

      if (!cur.name || (cur.type == FT_SYMLINK && !cur.linkto))
	error = 1;

      DEBUGP (("\n"));

      if (error || ignore)
	{
	  DEBUGP (("Skipping.\n"));
	  FREE_MAYBE (cur.name);
	  FREE_MAYBE (cur.linkto);
	  xfree (line);
	  continue;
	}

      if (!dir)
	{
	  l = dir = (struct fileinfo *)xmalloc (sizeof (struct fileinfo));
	  memcpy (l, &cur, sizeof (cur));
	  l->prev = l->next = NULL;
	}
      else
	{
	  cur.prev = l;
	  l->next = (struct fileinfo *)xmalloc (sizeof (struct fileinfo));
	  l = l->next;
	  memcpy (l, &cur, sizeof (cur));
	  l->next = NULL;
	}
      /* Get the current time.  */
      timenow = time (NULL);
      tnow = localtime (&timenow);
      /* Build the time-stamp (the idea by [e-mail]).  */
      timestruct.tm_sec   = sec;
      timestruct.tm_min   = min;
      timestruct.tm_hour  = hour;
      timestruct.tm_mday  = day;
      timestruct.tm_mon   = month;
      if (year == 0)
	{
	  /* Some listings will not specify the year if it is "obvious"
	     that the file was from the previous year.  E.g. if today
	     is 97-01-12, and you see a file of Dec 15th, its year is
	     1996, not 1997.  Thanks to Vladimir Volovich for
	     mentioning this!  */
	  if (month > tnow->tm_mon)
	    timestruct.tm_year = tnow->tm_year - 1;
	  else
	    timestruct.tm_year = tnow->tm_year;
	}
      else
	timestruct.tm_year = year;
      if (timestruct.tm_year >= 1900)
	timestruct.tm_year -= 1900;
      timestruct.tm_wday  = 0;
      timestruct.tm_yday  = 0;
      timestruct.tm_isdst = -1;
      l->tstamp = mktime (&timestruct); /* store the time-stamp */

      xfree (line);
    }

  fclose (fp);
  return dir;
}

static struct fileinfo *
ftp_parse_winnt_ls (const char *file)
{
  FILE *fp;
  int len;
  int year, month, day;         /* for time analysis */
  int hour, min;
  struct tm timestruct;

  char *line, *tok;             /* tokenizer */
  struct fileinfo *dir, *l, cur; /* list creation */

  fp = fopen (file, "rb");
  if (!fp)
    {
      logprintf (LOG_NOTQUIET, "%s: %s\n", file, strerror (errno));
      return NULL;
    }
  dir = l = NULL;

  /* Line loop to end of file: */
  while ((line = read_whole_line (fp)))
    {
      len = clean_line (line);

      /* Extracting name is a bit of black magic and we have to do it
         before `strtok' inserted extra \0 characters in the line
         string. For the moment let us just suppose that the name starts at
         column 39 of the listing. This way we could also recognize
         filenames that begin with a series of space characters (but who
         really wants to use such filenames anyway?). */
      if (len < 40) continue;
      tok = line + 39;
      cur.name = xstrdup(tok);
      DEBUGP(("Name: '%s'\n", cur.name));

      /* First column: mm-dd-yy. Should atoi() on the month fail, january
	 will be assumed.  */
      tok = strtok(line, "-");
      month = atoi(tok) - 1;
      if (month < 0) month = 0;
      tok = strtok(NULL, "-");
      day = atoi(tok);
      tok = strtok(NULL, " ");
      year = atoi(tok);
      /* Assuming the epoch starting at 1.1.1970 */
      if (year <= 70) year += 100;