gfileutils.c

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/* gfileutils.c - File utility functions
 *
 *  Copyright 2000 Red Hat, Inc.
 *
 * GLib is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * GLib 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with GLib; see the file COPYING.LIB.  If not,
 * write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 *   Boston, MA 02111-1307, USA.
 */

#include "glibconfig.h"

#include "glib.h"

#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>

#ifdef G_OS_WIN32
#include <io.h>
#ifndef F_OK
#define	F_OK 0
#define	X_OK 1
#define	W_OK 2
#define	R_OK 4
#endif /* !F_OK */

#ifndef S_ISREG
#define S_ISREG(mode) ((mode)&_S_IFREG)
#endif

#ifndef S_ISDIR
#define S_ISDIR(mode) ((mode)&_S_IFDIR)
#endif

#endif /* G_OS_WIN32 */

#ifndef S_ISLNK
#define S_ISLNK(x) 0
#endif

#ifndef O_BINARY
#define O_BINARY 0
#endif

#include "glibintl.h"

/**
 * g_file_test:
 * @filename: a filename to test
 * @test: bitfield of #GFileTest flags
 * 
 * Returns %TRUE if any of the tests in the bitfield @test are
 * %TRUE. For example, <literal>(G_FILE_TEST_EXISTS | 
 * G_FILE_TEST_IS_DIR)</literal> will return %TRUE if the file exists; 
 * the check whether it's a directory doesn't matter since the existence 
 * test is %TRUE. With the current set of available tests, there's no point
 * passing in more than one test at a time.
 * 
 * Apart from #G_FILE_TEST_IS_SYMLINK all tests follow symbolic links,
 * so for a symbolic link to a regular file g_file_test() will return
 * %TRUE for both #G_FILE_TEST_IS_SYMLINK and #G_FILE_TEST_IS_REGULAR.
 *
 * Note, that for a dangling symbolic link g_file_test() will return
 * %TRUE for #G_FILE_TEST_IS_SYMLINK and %FALSE for all other flags.
 *
 * Return value: whether a test was %TRUE
 **/
gboolean
g_file_test (const gchar *filename,
             GFileTest    test)
{
  if ((test & G_FILE_TEST_EXISTS) && (access (filename, F_OK) == 0))
    return TRUE;
  
  if ((test & G_FILE_TEST_IS_EXECUTABLE) && (access (filename, X_OK) == 0))
    return TRUE;

  if (test & G_FILE_TEST_IS_SYMLINK)
    {
#ifdef G_OS_WIN32
      /* no sym links on win32, no lstat in msvcrt */
#else
      struct stat s;

      if ((lstat (filename, &s) == 0) && S_ISLNK (s.st_mode))
        return TRUE;
#endif
    }
  
  if (test & (G_FILE_TEST_IS_REGULAR | G_FILE_TEST_IS_DIR))
    {
      struct stat s;
      
      if (stat (filename, &s) == 0)
	{
	  if ((test & G_FILE_TEST_IS_REGULAR) && S_ISREG (s.st_mode))
	    return TRUE;
	  
	  if ((test & G_FILE_TEST_IS_DIR) && S_ISDIR (s.st_mode))
	    return TRUE;
	}
    }

  return FALSE;
}

GQuark
g_file_error_quark (void)
{
  static GQuark q = 0;
  if (q == 0)
    q = g_quark_from_static_string ("g-file-error-quark");

  return q;
}

/**
 * g_file_error_from_errno:
 * @err_no: an "errno" value
 * 
 * Gets a #GFileError constant based on the passed-in @errno.
 * For example, if you pass in %EEXIST this function returns
 * #G_FILE_ERROR_EXIST. Unlike @errno values, you can portably
 * assume that all #GFileError values will exist.
 *
 * Normally a #GFileError value goes into a #GError returned
 * from a function that manipulates files. So you would use
 * g_file_error_from_errno() when constructing a #GError.
 * 
 * Return value: #GFileError corresponding to the given @errno
 **/
GFileError
g_file_error_from_errno (gint err_no)
{
  switch (err_no)
    {
#ifdef EEXIST
    case EEXIST:
      return G_FILE_ERROR_EXIST;
      break;
#endif

#ifdef EISDIR
    case EISDIR:
      return G_FILE_ERROR_ISDIR;
      break;
#endif

#ifdef EACCES
    case EACCES:
      return G_FILE_ERROR_ACCES;
      break;
#endif

#ifdef ENAMETOOLONG
    case ENAMETOOLONG:
      return G_FILE_ERROR_NAMETOOLONG;
      break;
#endif

#ifdef ENOENT
    case ENOENT:
      return G_FILE_ERROR_NOENT;
      break;
#endif

#ifdef ENOTDIR
    case ENOTDIR:
      return G_FILE_ERROR_NOTDIR;
      break;
#endif

#ifdef ENXIO
    case ENXIO:
      return G_FILE_ERROR_NXIO;
      break;
#endif

#ifdef ENODEV
    case ENODEV:
      return G_FILE_ERROR_NODEV;
      break;
#endif

#ifdef EROFS
    case EROFS:
      return G_FILE_ERROR_ROFS;
      break;
#endif

#ifdef ETXTBSY
    case ETXTBSY:
      return G_FILE_ERROR_TXTBSY;
      break;
#endif

#ifdef EFAULT
    case EFAULT:
      return G_FILE_ERROR_FAULT;
      break;
#endif

#ifdef ELOOP
    case ELOOP:
      return G_FILE_ERROR_LOOP;
      break;
#endif

#ifdef ENOSPC
    case ENOSPC:
      return G_FILE_ERROR_NOSPC;
      break;
#endif

#ifdef ENOMEM
    case ENOMEM:
      return G_FILE_ERROR_NOMEM;
      break;
#endif

#ifdef EMFILE
    case EMFILE:
      return G_FILE_ERROR_MFILE;
      break;
#endif

#ifdef ENFILE
    case ENFILE:
      return G_FILE_ERROR_NFILE;
      break;
#endif

#ifdef EBADF
    case EBADF:
      return G_FILE_ERROR_BADF;
      break;
#endif

#ifdef EINVAL
    case EINVAL:
      return G_FILE_ERROR_INVAL;
      break;
#endif

#ifdef EPIPE
    case EPIPE:
      return G_FILE_ERROR_PIPE;
      break;
#endif

#ifdef EAGAIN
    case EAGAIN:
      return G_FILE_ERROR_AGAIN;
      break;
#endif

#ifdef EINTR
    case EINTR:
      return G_FILE_ERROR_INTR;
      break;
#endif

#ifdef EIO
    case EIO:
      return G_FILE_ERROR_IO;
      break;
#endif

#ifdef EPERM
    case EPERM:
      return G_FILE_ERROR_PERM;
      break;
#endif
      
    default:
      return G_FILE_ERROR_FAILED;
      break;
    }
}

static gboolean
get_contents_stdio (const gchar *filename,
                    FILE        *f,
                    gchar      **contents,
                    gsize       *length, 
                    GError     **error)
{
  gchar buf[2048];
  size_t bytes;
  char *str;
  size_t total_bytes;
  size_t total_allocated;
  
  g_assert (f != NULL);

#define STARTING_ALLOC 64
  
  total_bytes = 0;
  total_allocated = STARTING_ALLOC;
  str = g_malloc (STARTING_ALLOC);
  
  while (!feof (f))
    {
      bytes = fread (buf, 1, 2048, f);

      while ((total_bytes + bytes + 1) > total_allocated)
        {
          total_allocated *= 2;
          str = g_try_realloc (str, total_allocated);

          if (str == NULL)
            {
              g_set_error (error,
                           G_FILE_ERROR,
                           G_FILE_ERROR_NOMEM,
                           _("Could not allocate %lu bytes to read file \"%s\""),
                           (gulong) total_allocated, filename);
              goto error;
            }
        }
      
      if (ferror (f))
        {
          g_set_error (error,
                       G_FILE_ERROR,
                       g_file_error_from_errno (errno),
                       _("Error reading file '%s': %s"),
                       filename, g_strerror (errno));

          goto error;
        }

      memcpy (str + total_bytes, buf, bytes);
      total_bytes += bytes;
    }

  fclose (f);

  str[total_bytes] = '\0';
  
  if (length)
    *length = total_bytes;
  
  *contents = str;
  
  return TRUE;

 error:

  g_free (str);
  fclose (f);
  
  return FALSE;  
}

#ifndef G_OS_WIN32

static gboolean
get_contents_regfile (const gchar *filename,
                      struct stat *stat_buf,
                      gint         fd,
                      gchar      **contents,
                      gsize       *length,
                      GError     **error)
{
  gchar *buf;
  size_t bytes_read;
  size_t size;
  size_t alloc_size;
  
  size = stat_buf->st_size;

  alloc_size = size + 1;
  buf = g_try_malloc (alloc_size);

  if (buf == NULL)
    {
      g_set_error (error,
                   G_FILE_ERROR,
                   G_FILE_ERROR_NOMEM,
                   _("Could not allocate %lu bytes to read file \"%s\""),
                   (gulong) alloc_size, filename);

      goto error;
    }
  
  bytes_read = 0;
  while (bytes_read < size)
    {
      gssize rc;
          
      rc = read (fd, buf + bytes_read, size - bytes_read);

      if (rc < 0)
        {
          if (errno != EINTR) 
            {
              g_free (buf);
                  
              g_set_error (error,
                           G_FILE_ERROR,
                           g_file_error_from_errno (errno),
                           _("Failed to read from file '%s': %s"),
                           filename, g_strerror (errno));

	      goto error;
            }
        }
      else if (rc == 0)
        break;
      else
        bytes_read += rc;
    }
      
  buf[bytes_read] = '\0';

  if (length)
    *length = bytes_read;
  
  *contents = buf;

  close (fd);

  return TRUE;

 error:

  close (fd);
  
  return FALSE;
}

static gboolean
get_contents_posix (const gchar *filename,
                    gchar      **contents,
                    gsize       *length,
                    GError     **error)
{
  struct stat stat_buf;
  gint fd;
  
  /* O_BINARY useful on Cygwin */
  fd = open (filename, O_RDONLY|O_BINARY);

  if (fd < 0)
    {
      g_set_error (error,
                   G_FILE_ERROR,
                   g_file_error_from_errno (errno),
                   _("Failed to open file '%s': %s"),