Resource fixes/changes

[wimlib] / src / wimlib.h

/*
 * wimlib.h
 *
 * External header for wimlib.
 */

/* 
 * Copyright (C) 2012 Eric Biggers
 *
 * This file is part of wimlib, a library for working with WIM files.
 *
 * wimlib 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 2.1 of the License, or (at your option)
 * any later version.
 *
 * wimlib 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 wimlib; if not, see http://www.gnu.org/licenses/.
 */

/** \mainpage
 *
 * \section intro Introduction
 *
 * wimlib is a C library to read, write, and mount archive files in the Windows
 * Imaging Format (WIM files).  These files are normally created using the @c
 * imagex.exe utility on Windows, but this library provides a free
 * implementetion of @c imagex for UNIX-based systems and an API to allow other
 * programs to read, write, and mount WIM files.  wimlib is comparable to
 * Microsoft's WIMGAPI, but was designed independently and is not a clone of it.
 * 
 * The main intended use of wimlib is to create customized images of Windows PE,
 * the Windows Preinstallation Environment, without having to rely on Windows.
 * Windows PE, which is the operating system that runs when you boot from the
 * Windows Vista or Windows 7 DVD, is a lightweight version of Windows that can
 * run entirely from memory. It can be used to install Windows from local media
 * or a network drive or perform maintenance. 
 * 
 * You can find Windows PE on the installation media for Windows Vista, Windows
 * 7, and Windows 8.  The Windows PE image itself is a WIM file, @c
 * sources/boot.wim, on the ISO filesystem.  Windows PE can also be found in the
 * Windows Automated Installation Kit (WAIK) inside the @c WinPE.cab file, which
 * you can extract if you install the @c cabextract program.
 *
 * \section format WIM files
 *
 * A <b>Windows Imaging (WIM)</b> file is an archive.  Like some other archive
 * formats such as ZIP, files in WIM archives may be compressed.  WIM archives
 * support two Microsoft-specific compression formats:  @b LZX and @b XPRESS.
 * Both are based on LZ77 and Huffman encoding, and both are supported by
 * wimlib.
 *
 * Unlike ZIP files, WIM files can contain multiple independent toplevel
 * directory trees known as @a images.  While each image has its own metadata,
 * files are not duplicated for each image; instead, each file is included only
 * once in the entire WIM. Microsoft did this so that in one WIM file, they
 * could do things like have 5 different versions of Windows that are almost
 * exactly the same.
 *
 * WIM files may contain a integrity table.  The integrity table, if it exists,
 * is located at the end of the WIM file and contains SHA1 message digests of
 * 10MB chunks of the WIM.
 *
 * Microsoft provides documentation for the WIM file format, XPRESS compression
 * format, and LZX compression format.  However, there are errors and omissions
 * in some places in their documentation.
 *
 * \section starting Getting Started
 *
 * wimlib uses the GNU autotools, so it should be easy to install with
 * <code>configure && make && sudo make install</code>, provided that you have
 * @c libxml2 and @c libfuse installed.  To use wimlib in a program after
 * installing it, include @c wimlib.h and link your program with @c -lwim.
 *
 * wimlib wraps up a WIM file in an opaque ::WIMStruct structure.
 *
 * All functions in wimlib's public API are prefixed with @c wimlib.  Most
 * return an integer error code on failure.  Use wimlib_get_error_string() to
 * get a string that describes an error code.  wimlib also can print error
 * messages itself when an error happens, and these may be more informative than
 * the error code; to enable this, call wimlib_set_print_errors().
 *
 * wimlib is thread-safe as long as different ::WIMStruct's are used, with the
 * following exceptions:  wimlib_set_print_errors() and
 * wimlib_set_memory_allocator() apply globally, and wimlib_mount() can only be
 * used by one ::WIMStruct at a time.
 *
 * To open an existing WIM, use wimlib_open_wim().
 *
 * To create a new WIM that initially contains no images, use
 * wimlib_create_new_wim().
 *
 * To add an image to a WIM file from a directory tree on your filesystem, call
 * wimlib_add_image().  This can be done with a ::WIMStruct gotten from
 * wimlib_open_wim() or from wimlib_create_new_wim().
 *
 * To extract an image from a WIM file, call wimlib_set_output_dir() to set the
 * output directory, then call wimlib_extract_image().
 *
 * wimlib supports mounting WIM files either read-only or read-write.  Mounting
 * is done using wimlib_mount() and unmounting is done using wimlib_unmount().
 * Mounting can be done without root privileges because it is implemented using
 * FUSE (Filesystem in Userspace).  If wimlib is compiled with the
 * <code>--without-fuse</code> flag, these functions will be available but will
 * fail.
 *
 * After creating or modifying a WIM file, you can write it to a file using
 * wimlib_write().  Alternatively,  if the WIM was originally read from a file,
 * you can use wimlib_overwrite() to overwrite the original file.  In some
 * cases, wimlib_overwrite_xml_and_header() can be used instead.
 *
 * After you are done with the WIM file, use wimlib_free() to free all memory
 * associated with a ::WIMStruct and close all files associated with it.
 *
 * To see an example of how to use wimlib, see the file
 * @c programs/imagex.c in wimlib's source tree.
 *
 * wimlib supports custom memory allocators; use wimlib_set_memory_allocator()
 * for this.
 *
 * \section imagex imagex
 *
 * wimlib comes with the <b>imagex</b> program, which is documented in man pages.
 *
 * \section mkwinpeimg mkwinpeimg
 * 
 * wimlib comes with the <b>mkwinpeimg</b> script, which is documented in a man
 * page.
 *
 * \section Limitations
 *
 * While wimlib supports the main features of WIM files, wimlib currently has
 * the following limitations:
 * - wimlib does not support modifying or creating "security data", which
 *   describes the access rights of the files in the WIM.  This data is very
 *   Windows-specific, and it would be difficult to do anything with it.
 *   Microsoft's software can still read a WIM without security data, including
 *   a boot.wim for Windows PE, but <b>do not expect to be able to use wimlib to
 *   image a Windows installation and preserve file attributes</b>.  However, by
 *   default, wimlib will preserve security data for existing WIMs.
 * - There is no way to directly extract or mount split WIMs.
 * - There is not yet any code to verify that there are no collisions between
 *   different files that happen to have the same SHA1 message digest.
 *   This is extremely unlikely, but could result in something bad such as a
 *   file going missing.
 * - Alternate stream entries for directory entries are ignored.
 * - Different versions of the WIM file format, if they even exist, are
 *   unsupported.  Let me know if you notice WIM files with a different version.
 * - Chunk sizes other than 32768 are unsupported (except for uncompressed WIMs,
 *   for which the chunk size field is ignored).  As far as I can tell, other
 *   chunk sizes are not used in compressed WIMs.  Let me know if you find a WIM
 *   file with a different chunk size.
 * - wimlib does not provide a clone of the @b PEImg tool that allows you to
 *   make certain Windows-specific modifications to a Windows PE image, such as
 *   adding a driver or Windows component.  Such a tool could conceivably be
 *   implemented on top of wimlib, although it likely would be hard to implement
 *   because it would have to do very Windows-specific things such as
 *   manipulating the driver store.  wimlib does provide the @b mkwinpeimg
 *   script for a similar purpose, however.  With regards to adding drivers to
 *   Windows PE, you have the option of putting them anywhere in the Windows PE
 *   image, then loading them after boot using @b drvload.exe.
 * - There is not yet a way to extract specific files or directories from a WIM
 *   file without mounting it, or to add, remove, or modify files in a WIM
 *   without mounting it, other than by adding or removing an entire image.  I
 *   can implement this if requested, but I intend the FUSE mount feature to be
 *   used for this purpose, as it is easy to do these things in whatever way you
 *   want after the image is mounted.
 *
 * Currently, Microsoft's @a image.exe can create slightly smaller WIM files
 * than wimlib when using maximum (LZX) compression because it knows how to
 * split up LZX compressed blocks, which is not yet implemented in wimlib.
 *
 * wimlib is experimental and likely contains bugs; use Microsoft's @a
 * imagex.exe if you want to make sure your WIM files are made "correctly".
 *
 * \section legal License
 *
 * The wimlib library is licensed under the GNU Lesser General Public License
 * version 2.1 or later.
 *
 * @b imagex and @b mkwinpeiso are licensed under the GNU General Public License
 * version 3 or later.
 */

#ifndef _WIMLIB_H
#define _WIMLIB_H

#include <stdio.h>
#include <stddef.h>
#include <stdbool.h>

#ifndef _WIMLIB_INTERNAL_H
/** 
 * Opaque structure that represents a WIM file. 
 */
typedef struct WIMStruct WIMStruct;
#endif

/** 
 * Specifies the way in which identical files are linked when extracting
 * image(s) from the WIM. 
 */
enum wim_link_type {
/** Hard link identical files when extracting files from the WIM. */
        WIM_LINK_TYPE_HARD = 0,
/** Symbolic link identical files when extracting files from the WIM. */
        WIM_LINK_TYPE_SYMBOLIC = 1,
/** Do not create links when extracting identical files from the WIM (default).
 * */
        WIM_LINK_TYPE_NONE = 2,
};

/**
 * Specifies the compression type of a WIM file.
 */

enum wim_compression_type {
        /** An invalid compression type. */
        WIM_COMPRESSION_TYPE_INVALID = -1,

        /** The WIM does not include any compressed resources. */
        WIM_COMPRESSION_TYPE_NONE = 0,

        /** Compressed resources in the WIM use LZX compression. */
        WIM_COMPRESSION_TYPE_LZX = 1,

        /** Compressed resources in the WIM use XPRESS compression. */
        WIM_COMPRESSION_TYPE_XPRESS = 2,
};

/** Mount the WIM read-write. */
#define WIMLIB_MOUNT_FLAG_READWRITE             0x00000001

/** For debugging only. (This passes the @c -d flag to @c fuse_main()).*/
#define WIMLIB_MOUNT_FLAG_DEBUG                 0x00000002

/** Do not allow accessing alternate data streams. */
#define WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_NONE         0x00000010

/** Access alternate data streams through extended file attributes.  This is the
 * default mode. */
#define WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR        0x00000020

/** Access alternate data streams by specifying the file name, a colon, then the
 * alternate file stream name. */
#define WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS      0x00000040

/** Include an integrity table in the new WIM being written during the unmount. 
 * Ignored for read-only mounts. */
#define WIMLIB_UNMOUNT_FLAG_CHECK_INTEGRITY     0x00000001

/** Unless this flag is given, changes to a mounted WIM are discarded.  Ignored
 * for read-only mounts. */
#define WIMLIB_UNMOUNT_FLAG_COMMIT              0x00000002

/** Include an integrity table in the new WIM file. */
#define WIMLIB_WRITE_FLAG_CHECK_INTEGRITY       0x00000001

/** Print progress information when writing the integrity table. */
#define WIMLIB_WRITE_FLAG_SHOW_PROGRESS         0x00000002

/** Print file paths as we write then */
#define WIMLIB_WRITE_FLAG_VERBOSE               0x00000004

/** Mark the image being added as the bootable image of the WIM. */
#define WIMLIB_ADD_IMAGE_FLAG_BOOT              0x00000001

/** Print the name of each file or directory as it is scanned to be included in
 * the WIM image. */
#define WIMLIB_ADD_IMAGE_FLAG_VERBOSE           0x00000002

/** Apply NTFS-specific information to the captured WIM image.  This flag can
 * only be specified if the directory being captured is on a NTFS filesystem
 * mounted with NTFS-3g, and wimlib was compiled with support for NTFS-3g  */
#define WIMLIB_ADD_IMAGE_FLAG_NTFS              0x00000004

/** Follow symlinks; archive and dump the files they point to. */
#define WIMLIB_ADD_IMAGE_FLAG_DEREFERENCE       0x00000008

/** See documentation for wimlib_export_image(). */
#define WIMLIB_EXPORT_FLAG_BOOT                 0x00000001

/** Verify the integrity of the WIM if an integrity table is present. */
#define WIMLIB_OPEN_FLAG_CHECK_INTEGRITY        0x00000001

/** Print progress information when verifying integrity table. */
#define WIMLIB_OPEN_FLAG_SHOW_PROGRESS          0x00000002

/** If this flag is not given, an error is issued if the WIM is part of a split
 * WIM.  */
#define WIMLIB_OPEN_FLAG_SPLIT_OK               0x00000004


/** When identical files are extracted from the WIM, hard link them together. */
#define WIMLIB_EXTRACT_FLAG_HARDLINK            0x00000001

/** When identical files are extracted from the WIM, symlink them together. */
#define WIMLIB_EXTRACT_FLAG_SYMLINK             0x00000002

/** Print the name of each file as it is extracted from the WIM image. */
#define WIMLIB_EXTRACT_FLAG_VERBOSE             0x00000008

/**
 * Possible values of the error code returned by many functions in wimlib.
 *
 * See the documentation for each wimlib function to see specifically what error
 * codes can be returned by a given function, and what they mean.
 */
enum wimlib_error_code {
        WIMLIB_ERR_SUCCESS = 0,
        WIMLIB_ERR_COMPRESSED_LOOKUP_TABLE,
        WIMLIB_ERR_DECOMPRESSION,
        WIMLIB_ERR_DELETE_STAGING_DIR,
        WIMLIB_ERR_FORK,
        WIMLIB_ERR_FUSE,
        WIMLIB_ERR_FUSERMOUNT,
        WIMLIB_ERR_IMAGE_COUNT,
        WIMLIB_ERR_IMAGE_NAME_COLLISION,
        WIMLIB_ERR_INTEGRITY,
        WIMLIB_ERR_INVALID_CHUNK_SIZE,
        WIMLIB_ERR_INVALID_COMPRESSION_TYPE,
        WIMLIB_ERR_INVALID_DENTRY,
        WIMLIB_ERR_INVALID_HEADER_SIZE,
        WIMLIB_ERR_INVALID_IMAGE,
        WIMLIB_ERR_INVALID_INTEGRITY_TABLE,
        WIMLIB_ERR_INVALID_PARAM,
        WIMLIB_ERR_INVALID_RESOURCE_SIZE,
        WIMLIB_ERR_INVALID_SECURITY_DATA,
        WIMLIB_ERR_LINK,
        WIMLIB_ERR_MKDIR,
        WIMLIB_ERR_MQUEUE,
        WIMLIB_ERR_NOMEM,
        WIMLIB_ERR_NOTDIR,
        WIMLIB_ERR_NOT_A_WIM_FILE,
        WIMLIB_ERR_NOT_ROOT,
        WIMLIB_ERR_NO_FILENAME,
        WIMLIB_ERR_NTFS_3G,
        WIMLIB_ERR_OPEN,
        WIMLIB_ERR_OPENDIR,
        WIMLIB_ERR_READLINK,
        WIMLIB_ERR_READ,
        WIMLIB_ERR_RENAME,
        WIMLIB_ERR_SPECIAL_FILE,
        WIMLIB_ERR_SPLIT_INVALID,
        WIMLIB_ERR_SPLIT_UNSUPPORTED,
        WIMLIB_ERR_STAT,
        WIMLIB_ERR_TIMEOUT,
        WIMLIB_ERR_UNKNOWN_VERSION,
        WIMLIB_ERR_UNSUPPORTED,
        WIMLIB_ERR_WRITE,
        WIMLIB_ERR_XML,
};


/** Used to indicate that no WIM image is currently selected. */
#define WIM_NO_IMAGE    0

/** Used to specify all images in the WIM. */
#define WIM_ALL_IMAGES  (-1)


/**
 * Adds an image to a WIM file from a directory tree on disk.
 *
 * The directory tree is read immediately for the purpose of constructing a
 * directory entry tree in-memory.  Also, all files are read to calculate their
 * SHA1 message digests.  However, because the directory tree may contain a very
 * large amount of data, the files themselves are not read into memory
 * permanently, and instead references to their paths saved.  This means that
 * the directory tree must not be modified, other than by adding entirely new
 * files or directories, before executing a call to wimlib_write() or
 * wimlib_overwrite(). Otherwise, wimlib_write() may fail or incorrect files may
 * be included in the WIM written by wimlib_write().
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file to which the image will be
 *      added.
 * @param dir
 *      A path to a directory in the outside filesystem.  It will become the
 *      root directory for the WIM image.
 * @param name
 *      The name to give the image.  This must be non-@c NULL.
 * @param description
 *      The description to give the image.  This parameter may be left @c
 *      NULL, in which case no description is given to the image.
 * @param flags_element
 *      What to put in the &lt;FLAGS&gt; element for the image's XML data.  This
 *      parameter may be left @c NULL, in which case no &lt;FLAGS&gt; element is
 *      given to the image.
 * @param flags
 *      If set to ::WIMLIB_ADD_IMAGE_FLAG_BOOT, change the image in @a wim
 *      marked as bootable to the one being added. Otherwise, leave the boot
 *      index unchanged.
 *
 * @return 0 on success; nonzero on error.  On error, changes to @a wim are
 * discarded so that it appears to be in the same state as when this function
 * was called.
 *
 * @retval ::WIMLIB_ERR_IMAGE_NAME_COLLISION 
 *      There is already an image named @a name in @a w.
 * @retval ::WIMLIB_ERR_INVALID_PARAM 
 *      @a dir was @c NULL, @a name was @c NULL, or @a name was the empty string.
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocate needed memory.
 * @retval ::WIMLIB_ERR_NOTDIR
 *      @a dir is not a directory.
 * @retval ::WIMLIB_ERR_OPEN
 *      Failed to open a file or directory in the directory tree rooted at @a
 *      dir.
 * @retval ::WIMLIB_ERR_READ
 *      Failed to read a file in the directory tree rooted at @a dir.
 * @retval ::WIMLIB_ERR_STAT
 *      Failed obtain the metadata for a file or directory in the directory tree
 *      rooted at @a dir.
 *
 */
extern int wimlib_add_image(WIMStruct *wim, const char *dir, 
                            const char *name, const char *description, 
                            const char *flags_element, int flags);

extern int wimlib_apply_image_to_ntfs_volume(WIMStruct *w, int image,
                                             const char *device, int flags);

/** 
 * Creates a WIMStruct for a new WIM file.
 *
 * @param ctype 
 *      The type of compression to be used in the new WIM file.  Must be
 *      ::WIM_COMPRESSION_TYPE_NONE, ::WIM_COMPRESSION_TYPE_LZX, or
 *      ::WIM_COMPRESSION_TYPE_XPRESS.
 * @param wim_ret
 *      On success, a pointer to an opaque ::WIMStruct for the new WIM file is
 *      written to the memory location pointed to by this paramater.  The
 *      ::WIMStruct must be freed using using wimlib_free() when finished with
 *      it.
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_INVALID_COMPRESSION_TYPE
 *      @a ctype was not ::WIM_COMPRESSION_TYPE_NONE,
 *      ::WIM_COMPRESSION_TYPE_LZX, or ::WIM_COMPRESSION_TYPE_XPRESS.
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocate needed memory.
 */
extern int wimlib_create_new_wim(int ctype, WIMStruct **wim_ret);

/**
 * Deletes an image, or all images, from a WIM file.
 *
 * All file resources referenced by the image(s) being deleted are removed from
 * the WIM if they are not referenced by any other images in the WIM.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for the WIM file that contains the image(s)
 *      being deleted.
 * @param image
 *      The number of the image to delete, or ::WIM_ALL_IMAGES to delete all
 *      images.
 * @return 0 on success; nonzero on error.  On error, @a wim is left in an
 * indeterminate state and should be freed with wimlib_free().
 * @retval ::WIMLIB_ERR_DECOMPRESSION
 *      Could not decompress the metadata resource for @a image.
 * @retval ::WIMLIB_ERR_INVALID_DENTRY
 *      A directory entry in the metadata resource for @a image in the WIM is
 *      invalid.
 * @retval ::WIMLIB_ERR_INVALID_IMAGE
 *      @a image does not exist in the WIM and is not ::WIM_ALL_IMAGES.
 * @retval ::WIMLIB_ERR_INVALID_RESOURCE_SIZE
 *      The metadata resource for @a image in the WIM is invalid.       
 * @retval ::WIMLIB_ERR_NOMEM Failed to allocate needed memory.
 * @retval ::WIMLIB_ERR_READ
 *      Could not read the metadata resource for @a image from the WIM.
 */
extern int wimlib_delete_image(WIMStruct *wim, int image);

/**
 * Copies an image, or all the images, from a WIM file, into another WIM file.
 *
 * @param src_wim
 *      Pointer to the ::WIMStruct for a WIM file that contains the image(s)
 *      being exported.
 * @param src_image
 *      The image to export from @a src_wim.  Can be the number of an image, or
 *      ::WIM_ALL_IMAGES to export all images.
 * @param dest_wim
 *      Pointer to the ::WIMStruct for a WIM filethat will receive the images being
 *      exported.
 * @param dest_name
 *      The name to give the exported image in the new WIM file.  If left @c NULL,
 *      the name from @a src_wim is used.  This parameter must be left @c NULL
 *      if @a src_image is ::WIM_ALL_IMAGES and @a src_wim contains more than one
 *      image; in that case, the names are all taken from the @a src_wim.
 * @param dest_description
 *      The description to give the exported image in the new WIM file.  If left
 *      @c NULL, the description from the @a src_wim is used.  This parameter must
 *      be left @c NULL if @a src_image is ::WIM_ALL_IMAGES and @a src_wim contains
 *      more than one image; in that case, the descriptions are all taken from
 *      @a src_wim.
 * @param flags
 *      ::WIMLIB_EXPORT_FLAG_BOOT if the image being exported is to be made
 *      bootable, or 0 if which image is marked as bootable in the destination
 *      WIM is to be left unchanged.  If @a src_image is ::WIM_ALL_IMAGES and
 *      there are multiple images in @a src_wim, specifying
 *      ::WIMLIB_EXPORT_FLAG_BOOT is valid only if one of the exported images is
 *      currently marked as bootable in @a src_wim; if that is the case, then
 *      that image is marked as bootable in the destination WIM.
 *
 * @return 0 on success; nonzero on error.  On error, @dest_wim is left in an
 * indeterminate state and should be freed with wimlib_free().
 * @retval ::WIMLIB_ERR_DECOMPRESSION
 *      Could not decompress the metadata resource for @a src_image
 *      in @a src_wim
 * @retval ::WIMLIB_ERR_IMAGE_NAME_COLLISION
 *      One or more of the names being given to an exported image was already in
 *      use in the destination WIM.
 * @retval ::WIMLIB_ERR_INVALID_DENTRY 
 *      A directory entry in the metadata resource for @a src_image in @a
 *      src_wim is invalid.
 * @retval ::WIMLIB_ERR_INVALID_IMAGE
 *      @a src_image does not exist in @a src_wim.
 * @retval ::WIMLIB_ERR_INVALID_PARAM
 *      ::WIMLIB_EXPORT_FLAG_BOOT was specified in @a flags, @a src_image was
 *      ::WIM_ALL_IMAGES, @a src_wim contains multiple images, and no images in
 *      @a src_wim are marked as bootable; or @a dest_name and/or @a
 *      dest_description were non-<code>NULL</code>, @a src_image was
 *      ::WIM_ALL_IMAGES, and @a src_wim contains multiple images.
 * @retval ::WIMLIB_ERR_INVALID_RESOURCE_SIZE
 *      The metadata resource for @a src_image in @a src_wim is invalid.        
 * @retval ::WIMLIB_ERR_NOMEM 
 *      Failed to allocate needed memory.
 * @retval ::WIMLIB_ERR_READ
 *      Could not read the metadata resource for @a src_image from @a src_wim.
 */
extern int wimlib_export_image(WIMStruct *src_wim, int src_image, 
                               WIMStruct *dest_wim, const char *dest_name, 
                               const char *dest_description, int flags);

/**
 * Extracts an image, or all images, from a WIM file.
 *
 * The output directory must have been previously set with
 * wimlib_set_output_dir().
 *
 * The link type used for extracted files is that specified by a previous call
 * to wimlib_set_link_type(), or ::WIM_LINK_TYPE_NONE by default.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param image
 *      The image to extract.  Can be the number of an image, or ::WIM_ALL_IMAGES
 *      to specify that all images are to be extracted.
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_DECOMPRESSION
 *      Could not decompress a resource (file or metadata) for @a image in @a
 *      wim.
 * @retval ::WIMLIB_ERR_INVALID_DENTRY 
 *      A directory entry in the metadata resource for @a image in @a wim is
 *      invalid.
 * @retval ::WIMLIB_ERR_INVALID_RESOURCE_SIZE
 *      A resource (file or metadata) for @a image in @a wim is invalid.        
 * @retval ::WIMLIB_ERR_LINK
 *      Failed to create a symbolic link or a hard link.
 * @retval ::WIMLIB_ERR_MKDIR
 *      Failed create a needed directory.
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocate needed memory.
 * @retval ::WIMLIB_ERR_NOTDIR
 *      wimlib_set_output_dir() has not been successfully called on @a wim.
 * @retval ::WIMLIB_ERR_OPEN
 *      Could not open one of the files being extracted for writing.
 * @retval ::WIMLIB_ERR_READ
 *      A unexpected end-of-file or read error occurred when trying to read data
 *      from the WIM file associated with @a wim.
 * @retval ::WIMLIB_ERR_WRITE
 *      Failed to write a file being extracted.
 */
extern int wimlib_extract_image(WIMStruct *wim, int image,
                                const char *output_dir, int flags);

/**
 * Extracts the XML data for a WIM file to a file stream.  Every WIM file
 * includes a string of XML that describes the images contained in the WIM.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param fp 
 *      @c stdout, or a FILE* opened for writing, to extract the data to.  
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_WRITE
 *      Failed to completely write the XML data to @a fp.
 */
extern int wimlib_extract_xml_data(WIMStruct *wim, FILE *fp);

/**
 * Frees all memory allocated for a WIMStruct and closes all files associated
 * with it. 
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 *
 * @return This function has no return value.
 */
extern void wimlib_free(WIMStruct *wim);

/**
 * Finds which image in a WIM is bootable.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * 
 * @return
 *      0 if no image is marked as bootable, or the number of the image marked
 *      as bootable (numbered starting at 1).
 */
extern int wimlib_get_boot_idx(const WIMStruct *wim);

/**
 * Gets the compression type used in the WIM.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file
 * 
 * @return
 *      ::WIM_COMPRESSION_TYPE_NONE, ::WIM_COMPRESSION_TYPE_LZX, or
 *      ::WIM_COMPRESSION_TYPE_XPRESS.
 */
extern int wimlib_get_compression_type(const WIMStruct *wim);

/**
 * Converts a compression type enumeration value into a string.
 *
 * @param ctype
 *      ::WIM_COMPRESSION_TYPE_NONE, ::WIM_COMPRESSION_TYPE_LZX,
 *      ::WIM_COMPRESSION_TYPE_XPRESS, or another value.
 *
 * @return
 *      A statically allocated string: "None", "LZX", "XPRESS", or "Invalid",
 *      respectively.
 */
extern const char *wimlib_get_compression_type_string(int ctype);

/**
 * Converts an error code into a string describing it.
 *
 * @param code
 *      The error code returned by one of wimlib's functions.
 *
 * @return
 *      Pointer to a statically allocated string describing the error code,
 *      or @c NULL if the error code is not valid.
 */
extern const char *wimlib_get_error_string(enum wimlib_error_code code);

/**
 * Returns the description of the specified image.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param image
 *      The number of the image, numbered starting at 1.
 *
 * @return
 *      The description of the image, or @c NULL if there is no such image, or @c NULL
 *      if the specified image has no description.
 */
extern const char *wimlib_get_image_description(const WIMStruct *wim, int image);

/**
 * Returns the name of the specified image.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param image
 *      The number of the image, numbered starting at 1.
 *
 * @return
 *      The name of the image, or @c NULL if there is no such image.
 */
extern const char *wimlib_get_image_name(const WIMStruct *wim, int image);


/**
 * Gets the number of images contained in the WIM.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * 
 * @return
 *      The number of images contained in the WIM file.
 */
extern int wimlib_get_num_images(const WIMStruct *wim);

/**
 * Gets the part number of the wim (in a split WIM).
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param total_parts_ret
 *      If non-@c NULL, the total number of parts in the split WIM (1 for
 *      non-split WIMs) is written to this location.
 *
 * @return 
 *      The part number of the WIM (1 for non-split WIMs)
 */
extern int wimlib_get_part_number(const WIMStruct *wim, int *total_parts_ret);

/**
 * Returns true if the WIM has an integrity table.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @return
 *      @c true if the WIM has an integrity table; false otherwise.
 */
extern bool wimlib_has_integrity_table(const WIMStruct *wim);


/**
 * Determines if an image name is already used by some image in the WIM.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param name
 *      The name to check.
 *
 * @return
 *      @c true if there is already an image in @a wim named @a name; @c
 *      false if there is no image named @a name in @a wim.
 */
extern bool wimlib_image_name_in_use(const WIMStruct *wim, const char *name);

/**
 * Joins a set of split WIMs into a one-part WIM.
 *
 * @param swms
 *      An array of strings that give the filenames of all parts of the split
 *      WIM.
 * @param num_swms
 *      Number of filenames in @a swms.
 * @param output_path
 *      The path to write the one-part WIM to.
 * @param flags
 *      ::WIMLIB_OPEN_FLAG_CHECK_INTEGRITY to check the split WIMs' integrity
 *      tables (if present) when opening them, and include an integrity table in
 *      the output WIM.
 *
 * @return 0 on success; nonzero on error.  This function may return any value
 * returned by wimlib_open_wim() except ::WIMLIB_ERR_SPLIT_UNSUPPORTED, as well
 * as the following error codes:
 *
 * @retval ::WIMLIB_ERR_SPLIT_INVALID
 *      The split WIMs do not form a valid WIM because they do not include all
 *      the parts of the original WIM, there are duplicate parts, or not all the
 *      parts have the same GUID and compression type.
 * @retval ::WIMLIB_ERR_WRITE
 *      An error occurred when trying to write data to the new WIM at @a output_path.
 *
 * Note that this function merely copies the resources, so it will not check to
 * see if the resources, including the metadata resource, are valid or not.
 */
extern int wimlib_join(const char **swms, int num_swms,
                       const char *output_path, int flags);

/**
 * Mounts an image in a WIM file on a directory read-only or read-write.
 *
 * A daemon will be forked to service the filesystem.
 *
 * If the mount is read-write, modifications to the WIM are staged in a staging
 * directory.
 *
 * wimlib_mount() currently cannot be used with multiple ::WIMStruct's without
 * intervening wimlib_unmount()s.  If there was a way to have libfuse pass a
 * pointer to user data to each FUSE callback, then this would be possible, but
 * there doesn't seem to be a way to do this currently.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for the WIM file to be mounted.
 * @param image
 *      The number of the image to mount, numbered from 1.  It must be an
 *      existing, single image.
 * @param dir
 *      The path to an existing directory to mount the image on.
 * @param flags
 *      Bitwise OR of the flags ::WIMLIB_MOUNT_FLAG_READWRITE or
 *      ::WIMLIB_MOUNT_FLAG_DEBUG.  If ::WIMLIB_MOUNT_FLAG_READWRITE is not
 *      given, the WIM is mounted read-only.
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_DECOMPRESSION
 *      Could not decompress the metadata resource for @a image in @a wim.
 * @retval ::WIMLIB_ERR_FUSE
 *      A non-zero status was returned by @c fuse_main().
 * @retval ::WIMLIB_ERR_INVALID_DENTRY 
 *      A directory entry in the metadata resource for @a image in @a wim is
 *      invalid.
 * @retval ::WIMLIB_ERR_INVALID_IMAGE
 *      @a image does not specify an existing, single image in @a wim.
 * @retval ::WIMLIB_ERR_INVALID_RESOURCE_SIZE
 *      The metadata resource for @a image in @a wim is invalid.        
 * @retval ::WIMLIB_ERR_MKDIR
 *      ::WIMLIB_MOUNT_FLAG_READWRITE was specified in @a flags, but the staging
 *      directory could not be created.
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocate needed memory.
 * @retval ::WIMLIB_ERR_NOTDIR
 *      Could not determine the current working directory.
 * @retval ::WIMLIB_ERR_READ
 *      An unexpected end-of-file or read error occurred when trying to read
 *      data from the WIM file associated with @a wim.
 *
 */
extern int wimlib_mount(WIMStruct *wim, int image, const char *dir, int flags);

/**
 * Opens a WIM file and creates a ::WIMStruct for it.
 *
 * @param wim_file 
 *      The path to the WIM file to open.
 * @param flags
 *      Bitwise OR of ::WIMLIB_OPEN_FLAG_CHECK_INTEGRITY and/or
 *      ::WIMLIB_OPEN_FLAG_SHOW_PROGRESS.
 *      If ::WIMLIB_OPEN_FLAG_CHECK_INTEGRITY is given, the integrity table
 *      of the WIM, if it exists, is checked, and the function will fail with an
 *      ::WIMLIB_ERR_INTEGRITY status if any of the computed SHA1 message
 *      digests of the WIM do not exactly match the corresponding message
 *      digests given in the integrity table.
 *      If ::WIMLIB_OPEN_FLAG_SHOW_PROGRESS is given, progress information will
 *      be shown if the integrity of the WIM is checked.
 *      If ::WIMLIB_OPEN_FLAG_SPLIT_OK is given, no error will be issued if the
 *      WIM is part of a split WIM.  However, wimlib does not fully support
 *      split WIMs, so not all functions will work correctly after opening a
 *      split WIM.  For example, you cannot use wimlib_mount() or
 *      wimlib_extract_image() on a split WIM.
 *
 * @param wim_ret
 *      On success, a pointer to an opaque ::WIMStruct for the opened WIM file
 *      is written to the memory location pointed to by this parameter.  The
 *      ::WIMStruct must be freed using using wimlib_free() when finished with
 *      it.
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_COMPRESSED_LOOKUP_TABLE
 *      The lookup table of @a wim_file is compressed.  Support for this can be
 *      added to wimlib if needed, but it appears to be the case that the lookup
 *      table is never compressed.
 * @retval ::WIMLIB_ERR_IMAGE_COUNT
 *      The WIM is not the non-first part of a split WIM, and the number of
 *      metadata resources found in the WIM did not match the image count given
 *      in the WIM header, or the number of &lt;IMAGE&gt; elements in the XML
 *      data for the WIM did not match the image count given in the WIM header.
 * @retval ::WIMLIB_ERR_INTEGRITY
 *      ::WIMLIB_OPEN_FLAG_CHECK_INTEGRITY was specified in @a flags and @a
 *      wim_file contains an integrity table, but the SHA1 message digest for a
 *      chunk of the WIM does not match the corresponding message digest given
 *      in the integrity table.
 * @retval ::WIMLIB_ERR_INVALID_CHUNK_SIZE
 *      Resources in @a wim_file are compressed, but the chunk size is not 32768.
 * @retval ::WIMLIB_ERR_INVALID_COMPRESSION_TYPE
 *      The header of @a wim_file says that resources in the WIM are compressed,
 *      but the header flag indicating LZX or XPRESS compression is not set.
 * @retval ::WIMLIB_ERR_INVALID_HEADER_SIZE
 *      The length field of the WIM header is not 208.
 * @retval ::WIMLIB_ERR_INVALID_INTEGRITY_TABLE
 *      ::WIMLIB_OPEN_FLAG_CHECK_INTEGRITY was specified in @a flags and @a
 *      wim_file contains an integrity table, but the integrity table is
 *      invalid.
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocated needed memory.
 * @retval ::WIMLIB_ERR_NOT_A_WIM_FILE
 *      @a wim_file does not begin with the expected magic characters.
 * @retval ::WIMLIB_ERR_OPEN
 *      Failed to open the file @a wim_file for reading.
 * @retval ::WIMLIB_ERR_READ
 *      An unexpected end-of-file or read error occurred when trying to read
 *      data from @a wim_file.
 * @retval ::WIMLIB_ERR_SPLIT_UNSUPPORTED
 *      @a wim_file is a split WIM, but ::WIMLIB_OPEN_FLAG_SPLIT_OK was not
 *      givin in @a flags.
 * @retval ::WIMLIB_ERR_UNKNOWN_VERSION
 *      A number other than 0x10d00 is written in the version field of the WIM
 *      header of @a wim_file.
 * @retval ::WIMLIB_ERR_XML
 *      The XML data for @a wim_file is invalid.
 */
extern int wimlib_open_wim(const char *wim_file, int flags, 
                           WIMStruct **wim_ret);

/**
 * Overwrites the file that the WIM was originally read from, with changes made.
 *
 * The new WIM is written to a temporary file and then renamed to the original
 * file after it is has been completely written.  The temporary file currently
 * is made in the same directory as the original WIM file.
 *
 * Note that it is not possible for this function to delete the original file
 * before having written the new file because it is very likely that file
 * resources in the new WIM file need to be retrieved from the old WIM file.
 *
 * After this function returns, @a wim must be freed using wimlib_free().  Any
 * further actions on @a wim before doing this are undefined.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for the WIM file to write.  There may have
 *      been in-memory changes made to it, which are then reflected in the
 *      output file.
 * @param flags 
 *      Bitwise OR of ::WIMLIB_WRITE_FLAG_CHECK_INTEGRITY and/or
 *      ::WIMLIB_WRITE_FLAG_SHOW_PROGRESS.
 *
 * @return 0 on success; nonzero on error.  This function may return any value
 * returned by wimlib_write() as well as the following error codes:
 * @retval ::WIMLIB_ERR_NO_FILENAME
 *      @a wim corresponds to a WIM created with wimlib_create_new_wim() rather
 *      than a WIM read with wimlib_open_wim().
 * @retval ::WIMLIB_ERR_RENAME
 *      The temporary file that the WIM was written to could not be renamed to
 *      the original filename of @a wim.
 */
extern int wimlib_overwrite(WIMStruct *wim, int flags);

/**
 * Updates the header and XML data of the WIM file, without the need to write
 * out the entire WIM to a temporary file as in wimlib_write().
 *
 * This function must only be used if no files, directories, or images have been
 * added, removed, or changed in the WIM.  It must be used when only the boot
 * index or the name or description of image(s) has been changed.
 *
 * After this function returns, @a wim must be freed using wimlib_free().  Any
 * further actions on @a wim before doing this are undefined.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for the WIM file to overwrite.
 * @param flags 
 *      Bitwise OR of ::WIMLIB_WRITE_FLAG_CHECK_INTEGRITY and/or
 *      ::WIMLIB_WRITE_FLAG_SHOW_PROGRESS.
 *
 * @return 0 on success; nonzero on error.
 *
 * @retval ::WIMLIB_ERR_NO_FILENAME
 *      @a wim corresponds to a WIM created with wimlib_create_new_wim() rather
 *      than a WIM read with wimlib_open_wim().
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocate needed memory.
 * @retval ::WIMLIB_ERR_OPEN
 *      The WIM file associated with @a wim could not be re-opened read-write.
 * @retval ::WIMLIB_ERR_READ
 *      ::WIMLIB_WRITE_FLAG_CHECK_INTEGRITY was specified in @a flags, but data
 *      from the WIM file associated with @a wim could not be read to compute
 *      the SHA1 message digests, or the old integrity table (if it existed)
 *      could not be read.
 * @retval ::WIMLIB_ERR_WRITE
 *      Failed to write the WIM header, the XML data, or the integrity table to
 *      the WIM file associated with @a wim.
 */
extern int wimlib_overwrite_xml_and_header(WIMStruct *wim, int flags);

/**
 * Prints information about one image, or all images, contained in a WIM.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param image 
 *      The image about which to print information.  Can be the number of an
 *      image, or ::WIM_ALL_IMAGES to print information about all images in the
 *      WIM.
 * 
 * @return This function has no return value.
 */
extern void wimlib_print_available_images(const WIMStruct *wim, int image);

/**
 * Prints the full paths to all files contained in an image, or all images, in a
 * WIM file.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param image 
 *      Which image to print files for.  Can be the number of an image, or
 *      ::WIM_ALL_IMAGES to print the files contained in all images.  
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_DECOMPRESSION
 *      The metadata resource for one of the specified images could not be
 *      decompressed.
 * @retval ::WIMLIB_ERR_INVALID_DENTRY
 *      A directory entry in the metadata resource for one of the specified
 *      images is invaled.
 * @retval ::WIMLIB_ERR_INVALID_IMAGE
 *      @a image does not specify a valid image in @a wim, and is not
 *      ::WIM_ALL_IMAGES.
 * @retval ::WIMLIB_ERR_INVALID_RESOURCE_SIZE
 *      The metadata resource for one of the specified images is invalid.
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocate needed memory.
 * @retval ::WIMLIB_ERR_READ
 *      An unexpected read error or end-of-file occurred when reading the
 *      metadata resource for one of the specified images.
 */
extern int wimlib_print_files(WIMStruct *wim, int image);

/**
 * Prints detailed information from the header of a WIM file.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 *
 * @return This function has no return value.
 *
 */
extern void wimlib_print_header(const WIMStruct *wim);

/** 
 * Prints the lookup table of a WIM file.  The lookup table maps SHA1 message
 * digests, as found in the directory entry tree in the WIM file, to file
 * resources in the WIM file.  This table includes one entry for each unique
 * file in the WIM, so it can be quite long.  There is only one lookup table per
 * WIM.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 *
 * @return This function has no return value.
 */
extern void wimlib_print_lookup_table(WIMStruct *wim);

/**
 * Prints the metadata of the specified image in a WIM file.  The metadata
 * consists of the security data as well as the directory entry tree, and each
 * image has its own metadata.  
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param image 
 *      Which image to print the metadata for.  Can be the number of an image,
 *      or ::WIM_ALL_IMAGES to print the metadata for all images in the WIM.
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_DECOMPRESSION
 *      The metadata resource for one of the specified images could not be
 *      decompressed.
 * @retval ::WIMLIB_ERR_INVALID_DENTRY
 *      A directory entry in the metadata resource for one of the specified
 *      images is invaled.
 * @retval ::WIMLIB_ERR_INVALID_IMAGE
 *      @a image does not specify a valid image in @a wim, and is not
 *      ::WIM_ALL_IMAGES.
 * @retval ::WIMLIB_ERR_INVALID_RESOURCE_SIZE
 *      The metadata resource for one of the specified images is invalid.
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocate needed memory.
 * @retval ::WIMLIB_ERR_READ
 *      An unexpected read error or end-of-file occurred when reading the
 *      metadata resource for one of the specified images.
 */
extern int wimlib_print_metadata(WIMStruct *wim, int image);

/**
 * Prints some basic information about a WIM file.  All information printed by
 * this function is also printed by wimlib_print_header(), but
 * wimlib_print_wim_information() prints some of this information more concisely
 * and in a more readable form.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 *
 * @return This function has no return value.  
 */
extern void wimlib_print_wim_information(const WIMStruct *wim);

/**
 * Translates a string specifying the name or number of an image in the WIM into
 * the number of the image.  The images are numbered starting at 1.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param image_name_or_num  
 *      A string specifying which image.  If it begins with a number, it is
 *      taken to be a string specifying the image number.  Otherwise, it is
 *      taken to be the name of an image, as specified in the XML data for the
 *      WIM file.  It also may be the keyword "all", which will resolve to
 *      ::WIM_ALL_IMAGES.
 *
 * @return 
 *      If the string resolved to a single existing image, the number of that
 *      image, counting starting at 1, is returned.  If the keyword "all" was
 *      specified, ::WIM_ALL_IMAGES is returned.  Otherwise, ::WIM_NO_IMAGE is
 *      returned.
 */
extern int wimlib_resolve_image(WIMStruct *wim, const char *image_name_or_num);

/**
 * Sets which image in the WIM is marked as bootable.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param boot_idx
 *      The number of the image to mark as bootable, or 0 to mark no image as
 *      bootable.
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_INVALID_IMAGE 
 *      @a boot_idx does not specify an existing image in @a wim, and it was not
 *      0.
 */
extern int wimlib_set_boot_idx(WIMStruct *wim, int boot_idx);

/**
 * Changes the description of an image in the WIM.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param image
 *      The number of the image for which to change the description.
 * @param description
 *      The new description to give the image.  It may be @c NULL, which
 *      indicates that the image is to be given no description.
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_INVALID_IMAGE
 *      @a image does not specify a single existing image in @a wim.
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocate the memory needed to duplicate the @a description
 *      string.
 */
extern int wimlib_set_image_descripton(WIMStruct *wim, int image, 
                                       const char *description);

/**
 * Changes the name of an image in the WIM.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.
 * @param image
 *      The number of the image for which to change the name.
 * @param name
 *      The new name to give the image.  It must not be @c NULL.
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_IMAGE_NAME_COLLISION
 *      There is already an image named @a name in @a wim.
 * @retval ::WIMLIB_ERR_INVALID_PARAM
 *      @a name was @c NULL or the empty string.
 * @retval ::WIMLIB_ERR_INVALID_IMAGE
 *      @a image does not specify a single existing image in @a wim.
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocate the memory needed to duplicate the @a name string.
 */
extern int wimlib_set_image_name(WIMStruct *wim, int image, const char *name);

/**
 * Sets the link type to use when extracting files from a WIM.  This applies
 * when extracting one image as well as when extracting all images.  Cross-image
 * links may save a lot of space because it is common for files to be referenced
 * multiple times in WIM files.  By default, the link type used for extraction
 * is ::WIM_LINK_TYPE_NONE, meaning that links are not created.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file
 * @param link_type
 *      ::WIM_LINK_TYPE_NONE, ::WIM_LINK_TYPE_SYMBOLIC, or ::WIM_LINK_TYPE_HARD.
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_INVALID_PARAM
 *      @a link_type was not ::WIM_LINK_TYPE_NONE, ::WIM_LINK_TYPE_SYMBOLIC,
 *      or ::WIM_LINK_TYPE_HARD.
 */
extern int wimlib_set_link_type(WIMStruct *wim, int link_type);

/**
 * Set the functions that wimlib uses to allocate and free memory.
 *
 * These settings are global and not per-WIM.
 *
 * The default is to use the default @c malloc() and @c free() from the C
 * library.
 *
 * @param malloc_func
 *      A function equivalent to @c malloc() that wimlib will use to allocate
 *      memory.  If @c NULL, the allocator function is set back to the default
 *      @c malloc() from the C library.
 * @param free_func
 *      A function equivalent to @c free() that wimlib will use to free memory.
 *      If @c NULL, the free function is set back to the default @c free() from
 *      the C library.
 * @param realloc_func
 *      A function equivalent to @c realloc() that wimlib will use to reallocate
 *      memory.  If @c NULL, the free function is set back to the default @c
 *      realloc() from the C library.
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_UNSUPPORTED
 *      wimlib was compiled with the @c --without-custom-memory-allocator flag,
 *      so custom memory allocators are unsupported.
 */
int wimlib_set_memory_allocator(void *(*malloc_func)(size_t),
                                 void (*free_func)(void *),
                                 void *(*realloc_func)(void *, size_t));

/**
 * Sets whether wimlib is to print error messages to @c stderr when a function
 * fails or not.  These error messages may provide information that cannot be
 * determined only from the error code that is returned.
 *
 * This setting is global and not per-WIM.
 *
 * By default, error messages are not printed.
 *
 * @param show_messages
 *      @c true if error messages are to be printed; @c false if error messages
 *      are not to be printed.
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_UNSUPPORTED
 *      @a show_messages was @c true, but wimlib was compiled with the @c
 *      --without-error-messages option.   Therefore, error messages cannot be
 *      shown.
 */
extern int wimlib_set_print_errors(bool show_messages);

/**
 * Splits a WIM into multiple parts.
 *
 * @param wimfile
 *      Name of the WIM file to split.  It must be a standalone, one-part WIM.
 * @param swm_name
 *      Name of the SWM file to create.  This will be the name of the first
 *      part.  The other parts will have the same name with 2, 3, 4, ..., etc.
 *      appended.
 * @param part_size
 *      The maximum size per part.  It is not guaranteed that this will really
 *      be the maximum size per part, because some file resources in the WIM may
 *      be larger than this size, and the WIM file format provides no way to
 *      split up file resources among multiple WIMs.
 * @param flags
 *      Bitwise OR of ::WIMLIB_OPEN_FLAG_CHECK_INTEGRITY and/or
 *      ::WIMLIB_OPEN_FLAG_SHOW_PROGRESS.
 *
 * @return 0 on success; nonzero on error.  This function may return any value
 * returned by wimlib_open_wim() as well as the following error codes:
 *
 * @retval ::WIMLIB_ERR_WRITE
 *      An error occurred when trying to write data to one of the split WIMs.
 *
 */
extern int wimlib_split(const char *wimfile, const char *swm_name, 
                        size_t part_size, int flags);

/**
 * Unmounts a WIM image that was mounted using wimlib_mount().
 *
 * Blocks until it is known whether the mount succeeded or failed.
 *
 * To perform this operation, the process calling wimlib_unmount() communicates
 * with the process that had called wimlib_mount().
 *
 * There is currently a design problem with this function because it is hard to
 * know whether the filesystem daemon is still working or whether it has
 * crashed, has been killed, or has reached an infinite loop. However, ideally
 * there should be no infinite loops or crashes in the code, so this wouldn't be
 * much of a problem.  Currently, a timeout of 600 seconds (so long because WIMs
 * can be very large) is implemented so that this function will not wait forever
 * before returning failure.  
 *
 * @param dir
 *      The directory that the WIM image was mounted on.
 * @param flags
 *      Bitwise OR of the flags ::WIMLIB_UNMOUNT_FLAG_CHECK_INTEGRITY or
 *      ::WIMLIB_UNMOUNT_FLAG_COMMIT.  Neither of these flags affect read-only
 *      mounts.
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_DELETE_STAGING_DIR
 *      The filesystem daemon was unable to remove the staging directory and the
 *      temporary files that it contains.
 * @retval ::WIMLIB_ERR_FORK
 *      Could not @c fork() the process.
 * @retval ::WIMLIB_ERR_FUSERMOUNT
 *      The @b fusermount program could not be executed or exited with a failure
 *      status.
 * @retval ::WIMLIB_ERR_MQUEUE
 *      Could not open a POSIX message queue to communicate with the filesystem
 *      daemon servicing the mounted filesystem, could not send a message
 *      through the queue, or could not receive a message through the queue.
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocate needed memory.
 * @retval ::WIMLIB_ERR_OPEN
 *      The filesystem daemon could not open a temporary file for writing the
 *      new WIM.
 * @retval ::WIMLIB_ERR_TIMEOUT
 *      600 seconds elapsed while waiting for the filesystem daemon to notify
 *      the process of its exit status, so the WIM file probably was not written
 *      successfully.
 * @retval ::WIMLIB_ERR_READ
 *      A read error occurred when the filesystem daemon tried to a file from
 *      the staging directory
 * @retval ::WIMLIB_ERR_RENAME
 *      The filesystem daemon failed to rename the newly written WIM file to the
 *      original WIM file.
 * @retval ::WIMLIB_ERR_WRITE
 *      A write error occurred when the filesystem daemon was writing to the new
 *      WIM file, or the filesystem daemon was unable to flush changes that had
 *      been made to files in the staging directory.
 */
extern int wimlib_unmount(const char *dir, int flags);

/**
 * Writes the WIM to a file.
 *
 * @param wim
 *      Pointer to the ::WIMStruct for a WIM file.  There may have been
 *      in-memory changes made to it, which are then reflected in the output
 *      file.
 * @param path
 *      The path to the file to write the WIM to.
 * @param image
 *      The image inside the WIM to write.  Use ::WIM_ALL_IMAGES to include all
 *      images.
 * @param flags 
 *      Bitwise OR of ::WIMLIB_WRITE_FLAG_CHECK_INTEGRITY and/or
 *      ::WIMLIB_WRITE_FLAG_SHOW_PROGRESS.  If
 *      ::WIMLIB_WRITE_FLAG_CHECK_INTEGRITY is given, an integrity table is
 *      included in the WIM being written.  If ::WIMLIB_WRITE_FLAG_SHOW_PROGRESS
 *      is given, the progress of the calculation of the integrity table is
 *      shown.
 *
 * @return 0 on success; nonzero on error.
 * @retval ::WIMLIB_ERR_DECOMPRESSION
 *      Failed to decompress a metadata or file resource in @a wim.
 * @retval ::WIMLIB_ERR_INVALID_DENTRY 
 *      A directory entry in the metadata resource for @a image in @a wim is
 *      invalid.
 * @retval ::WIMLIB_ERR_INVALID_IMAGE
 *      @a image does not specify a single existing image in @a wim, and is not
 *      ::WIM_ALL_IMAGES.
 * @retval ::WIMLIB_ERR_INVALID_RESOURCE_SIZE
 *      The metadata resource for @a image in @a wim is invalid.        
 * @retval ::WIMLIB_ERR_NOMEM
 *      Failed to allocate needed memory.
 * @retval ::WIMLIB_ERR_OPEN
 *      Failed to open @a path for writing, or some file resources in @a
 *      wim refer to files in the outside filesystem, and one of these files
 *      could not be opened for reading.
 * @retval ::WIMLIB_ERR_READ
 *      An error occurred when trying to read data from the WIM file associated
 *      with @a wim, or some file resources in @a wim refer to files in the
 *      outside filesystem, and a read error occurred when reading one of these
 *      files.
 * @retval ::WIMLIB_ERR_WRITE
 *      An error occurred when trying to write data to the new WIM file at @a
 *      path.
 */
extern int wimlib_write(WIMStruct *wim, const char *path, int image, int flags);



#endif /* _WIMLIB_H */