physfs/physfs.h

822 lines
33 KiB
C

/**
* PhysicsFS; a portable, flexible file i/o abstraction.
*
* This API gives you access to a system file system in ways superior to the
* stdio or system i/o calls. The brief benefits:
*
* - It's portable.
* - It's safe. No file access is permitted outside the specified dirs.
* - It's flexible. Archives (.ZIP files) can be used transparently as
* directory structures.
*
* This system is largely inspired by Quake 3's PK3 files and the related
* fs_* cvars. If you've ever tinkered with these, then this API will be
* familiar to you.
*
* With PhysicsFS, you have a single writing directory and multiple
* directories (the "search path") for reading. You can think of this as a
* filesystem within a filesystem. If (on Windows) you were to set the
* writing directory to "C:\MyGame\MyWritingDirectory", then no PHYSFS calls
* could touch anything above this directory, including the "C:\MyGame" and
* "C:\" directories. This prevents an application's internal scripting
* language from piddling over c:\config.sys, for example. If you'd rather
* give PHYSFS full access to the system's REAL file system, set the writing
* dir to "C:\", but that's generally A Bad Thing for several reasons.
*
* Drive letters are hidden in PhysicsFS once you set up your initial paths.
* The search path creates a single, hierarchical directory structure.
* Not only does this lend itself well to general abstraction with archives,
* it also gives better support to operating systems like MacOS and Unix.
* Generally speaking, you shouldn't ever hardcode a drive letter; not only
* does this hurt portability to non-Microsoft OSes, but it limits your win32
* users to a single drive, too. Use the PhysicsFS abstraction functions and
* allow user-defined configuration options, too. When opening a file, you
* specify it like it was on a Unix filesystem: if you want to write to
* "C:\MyGame\MyConfigFiles\game.cfg", then you might set the write dir to
* "C:\MyGame" and then open "MyConfigFiles/game.cfg". This gives an
* abstraction across all platforms. Specifying a file in this way is termed
* "platform-independent notation" in this documentation. Specifying a
* a filename in a form such as "C:\mydir\myfile" or
* "MacOS hard drive:My Directory:My File" is termed "platform-dependent
* notation". The only time you use platform-dependent notation is when
* setting up your write directory and search path; after that, all file
* access into those directories are done with platform-independent notation.
*
* All files opened for writing are opened in relation to the write directory,
* which is the root of the writable filesystem. When opening a file for
* reading, PhysicsFS goes through the search path. This is NOT the
* same thing as the PATH environment variable. An application using
* PhysicsFS specifies directories to be searched which may be actual
* directories, or archive files that contain files and subdirectories of
* their own. See the end of these docs for currently supported archive
* formats.
*
* Once the search path is defined, you may open files for reading. If you've
* got the following search path defined (to use a win32 example again):
*
* C:\mygame
* C:\mygame\myuserfiles
* D:\mygamescdromdatafiles
* C:\mygame\installeddatafiles.zip
*
* Then a call to PHYSFS_openRead("textfiles/myfile.txt") (note the directory
* separator, lack of drive letter, and lack of dir separator at the start of
* the string; this is platform-independent notation) will check for
* C:\mygame\textfiles\myfile.txt, then
* C:\mygame\myuserfiles\textfiles\myfile.txt, then
* D:\mygamescdromdatafiles\textfiles\myfile.txt, then, finally, for
* textfiles\myfile.txt inside of C:\mygame\installeddatafiles.zip. Remember
* that most archive types and platform filesystems store their filenames in
* a case-sensitive manner, so you should be careful to specify it correctly.
*
* Files opened through PhysicsFS may NOT contain "." or ".." or ":" as dir
* elements. Not only are these meaningless on MacOS and/or Unix, they are a
* security hole. Also, symbolic links (which can be found in some archive
* types and directly in the filesystem on Unix platforms) are NOT followed
* until you call PHYSFS_permitSymbolicLinks(). That's left to your own
* discretion, as following a symlink can allow for access outside the write
* dir and search paths. There is no mechanism for creating new symlinks in
* PhysicsFS.
*
* The write dir is not included in the search path unless you specifically
* add it. While you CAN change the write dir as many times as you like,
* you should probably set it once and stick to it. Remember that your
* program will not have permission to write in every directory on Unix and
* NT systems.
*
* All files are opened in binary mode; there is no endline conversion for
* textfiles. Other than that, PhysicsFS has some convenience functions for
* platform-independence. There is a function to tell you the current
* platform's dir separator ("\\" on windows, "/" on Unix, ":" on MacOS),
* which is needed only to set up your search/write paths. There is a
* function to tell you what CD-ROM drives contain accessible discs, and a
* function to recommend a good search path, etc.
*
* A recommended order for the search path is the write dir, then the base dir,
* then the cdrom dir, then any archives discovered. Quake 3 does something
* like this, but moves the archives to the start of the search path. Build
* Engine games, like Duke Nukem 3D and Blood, place the archives last, and
* use the base dir for both searching and writing. There is a helper
* function (PHYSFS_setSaneConfig()) that puts together a basic configuration
* for you, based on a few parameters. Also see the comments on
* PHYSFS_getBaseDir(), and PHYSFS_getUserDir() for info on what those
* are and how they can help you determine an optimal search path.
*
* PhysicsFS is (sort of) NOT thread safe! The error messages returned by
* PHYSFS_getLastError are unique by thread, but that's it. Generally
* speaking, we'd have to request a mutex at the start of each function,
* and release it before returning. Not only is this REALLY slow, it requires
* a thread lock portability layer to be written. All that work is only
* necessary as a safety if the calling application is poorly written.
* Generally speaking, it is safe to call most functions that don't set state
* simultaneously; you can read and write and open and close different files
* at the same time in different threads, but trying to set the write path in
* one thread while opening a file for writing in another will, at best,
* cause a polite error, but depending on the race condition results, you may
* get a segfault and crash, too. Use your head, and implement you own thread
* locks where needed. Also, consider if you REALLY need a multithreaded
* solution in the first place.
*
* While you CAN use stdio/syscall file access in a program that has PHYSFS_*
* calls, doing so is not recommended, and you can not use system
* filehandles with PhysicsFS filehandles and vice versa.
*
* Note that archives need not be named as such: if you have a ZIP file and
* rename it with a .PKG extension, the file will still be recognized as a
* ZIP archive by PhysicsFS; the file's contents are used to determine its
* type.
*
* Currently supported archive types:
* - .ZIP (pkZip/WinZip/Info-ZIP compatible)
*
* Please see the file LICENSE in the source's root directory.
*
* This file written by Ryan C. Gordon.
*/
#ifndef _INCLUDE_PHYSFS_H_
#define _INCLUDE_PHYSFS_H_
#ifdef __cplusplus
extern "C" {
#endif
typedef struct __PHYSFS_FILE__
{
void *opaque;
} PHYSFS_file;
typedef struct __PHYSFS_ARCHIVEINFO__
{
const char *extension;
const char *description;
const char *author;
const char *url;
} PHYSFS_ArchiveInfo;
/* functions... */
typedef struct __PHYSFS_VERSION__
{
int major;
int minor;
int patch;
} PHYSFS_Version;
#define PHYSFS_VER_MAJOR 0
#define PHYSFS_VER_MINOR 1
#define PHYSFS_VER_PATCH 1
#define PHYSFS_VERSION(x) { \
(x)->major = PHYSFS_VER_MAJOR; \
(x)->minor = PHYSFS_VER_MINOR; \
(x)->patch = PHYSFS_VER_PATCH; \
}
/**
* Get the version of PhysicsFS that is linked against your program. If you
* are using a shared library (DLL) version of PhysFS, then it is possible
* that it will be different than the version you compiled against.
*
* This is a real function; the macro PHYSFS_VERSION tells you what version
* of PhysFS you compiled against:
*
* PHYSFS_Version compiled;
* PHYSFS_Version linked;
*
* PHYSFS_VERSION(&compiled);
* PHYSFS_getLinkedVersion(&linked);
* printf("We compiled against PhysFS version %d.%d.%d ...\n",
* compiled.major, compiled.minor, compiled.patch);
* printf("But we linked against PhysFS version %d.%d.%d.\n",
* linked.major, linked.minor, linked.patch);
*
* This function may be called safely at any time, even before PHYSFS_init().
*/
void PHYSFS_getLinkedVersion(PHYSFS_Version *ver);
/**
* Initialize PhysicsFS. This must be called before any other PhysicsFS
* function.
*
* This should be called prior to any attempts to change your process's
* current working directory.
*
* @param argv0 the argv[0] string passed to your program's mainline.
* @return nonzero on success, zero on error. Specifics of the error can be
* gleaned from PHYSFS_getLastError().
*/
int PHYSFS_init(const char *argv0);
/**
* Shutdown PhysicsFS. This closes any files opened via PhysicsFS, blanks the
* search/write paths, frees memory, and invalidates all of your handles.
*
* Note that this call can FAIL if there's a file open for writing that
* refuses to close (for example, the underlying operating system was
* buffering writes to network filesystem, and the fileserver has crashed,
* or a hard drive has failed, etc). It is usually best to close all write
* handles yourself before calling this function, so that you can gracefully
* handle a specific failure.
*
* Once successfully deinitialized, PHYSFS_init() can be called again to
* restart the subsystem. All defaults API states are restored at this
* point.
*
* @return nonzero on success, zero on error. Specifics of the error can be
* gleaned from PHYSFS_getLastError(). If failure, state of PhysFS is
* undefined, and probably badly screwed up.
*/
int PHYSFS_deinit(void);
/**
* Get a list of archive types supported by this implementation of PhysicFS.
* These are the file formats usable for search path entries. This is for
* informational purposes only. Note that the extension listed is merely
* convention: if we list "ZIP", you can open a PkZip-compatible archive
* with an extension of "XYZ", if you like.
*
* The returned value is an array of pointers to PHYSFS_ArchiveInfo structures,
* with a NULL entry to signify the end of the list:
*
* PHYSFS_ArchiveInfo **i;
*
* for (i = PHYSFS_supportedArchiveTypes(); *i != NULL; i++)
* {
* printf("Supported archive: [%s], which is [%s].\n",
* i->extension, i->description);
* }
*
* The return values are pointers to static internal memory, and should
* be considered READ ONLY, and never freed.
*
* @return READ ONLY Null-terminated array of READ ONLY structures.
*/
const PHYSFS_ArchiveInfo **PHYSFS_supportedArchiveTypes(void);
/**
* Certain PhysicsFS functions return lists of information that are
* dynamically allocated. Use this function to free those resources.
*
* @param list List of information specified as freeable by this function.
*/
void PHYSFS_freeList(void *list);
/**
* Get the last PhysicsFS error message as a null-terminated string.
* This will be NULL if there's been no error since the last call to this
* function. The pointer returned by this call points to an internal buffer.
* Each thread has a unique error state associated with it, but each time
* a new error message is set, it will overwrite the previous one associated
* with that thread. It is safe to call this function at anytime, even
* before PHYSFS_init().
*
* @return READ ONLY string of last error message.
*/
const char *PHYSFS_getLastError(void);
/**
* Get a platform-dependent dir separator. This is "\\" on win32, "/" on Unix,
* and ":" on MacOS. It may be more than one character, depending on the
* platform, and your code should take that into account. Note that this is
* only useful for setting up the search/write paths, since access into those
* dirs always use '/' (platform-independent notation) to separate
* directories. This is also handy for getting platform-independent access
* when using stdio calls.
*
* @return READ ONLY null-terminated string of platform's dir separator.
*/
const char *PHYSFS_getDirSeparator(void);
/**
* Enable symbolic links. Some physical filesystems and archives contain
* files that are just pointers to other files. On the physical filesystem,
* opening such a link will (transparently) open the file that is pointed to.
*
* By default, PhysicsFS will check if a file is really a symlink during open
* calls and fail if it is. Otherwise, the link could take you outside the
* write and search paths, and compromise security.
*
* If you want to take that risk, call this function with a non-zero parameter.
* Note that this is more for sandboxing a program's scripting language, in
* case untrusted scripts try to compromise the system. Generally speaking,
* a user could very well have a legitimate reason to set up a symlink, so
* unless you feel there's a specific danger in allowing them, you should
* permit them.
*
* Symlinks are only explicitly checked when dealing with filenames
* in platform-independent notation. That is, when setting up your
* search and write paths, etc, symlinks are never checked for.
*
* Symbolic link permission can be enabled or disabled at any time, and is
* disabled by default.
*
* @param allow nonzero to permit symlinks, zero to deny linking.
*/
void PHYSFS_permitSymbolicLinks(int allow);
/**
* Get an array of dirs to available CD-ROM drives.
*
* The dirs returned are platform-dependent ("D:\" on Win32, "/cdrom" or
* whatnot on Unix). Dirs are only returned if there is a disc ready and
* accessible in the drive. So if you've got two drives (D: and E:), and only
* E: has a disc in it, then that's all you get. If the user inserts a disc
* in D: and you call this function again, you get both drives. If, on a
* Unix box, the user unmounts a disc and remounts it elsewhere, the next
* call to this function will reflect that change. Fun.
*
* The returned value is an array of strings, with a NULL entry to signify the
* end of the list:
*
* char **cds = PHYSFS_getCdRomDirs();
* char **i;
*
* for (i = cds; *i != NULL; i++)
* printf("cdrom dir [%s] is available.\n", *i);
*
* PHYSFS_freeList(cds);
*
* This call may block while drives spin up. Be forewarned.
*
* When you are done with the returned information, you may dispose of the
* resources by calling PHYSFS_freeList() with the returned pointer.
*
* @return Null-terminated array of null-terminated strings.
*/
char **PHYSFS_getCdRomDirs(void);
/**
* Helper function.
*
* Get the "base dir". This is the directory where the application was run
* from, which is probably the installation directory, and may or may not
* be the process's current working directory.
*
* You should probably use the base dir in your search path.
*
* @return READ ONLY string of base dir in platform-dependent notation.
*/
const char *PHYSFS_getBaseDir(void);
/**
* Helper function.
*
* Get the "user dir". This is meant to be a suggestion of where a specific
* user of the system can store files. On Unix, this is her home directory.
* On systems with no concept of multiple home directories (MacOS, win95),
* this will default to something like "C:\mybasedir\users\username"
* where "username" will either be the login name, or "default" if the
* platform doesn't support multiple users, either.
*
* You should probably use the user dir as the basis for your write dir, and
* also put it near the beginning of your search path.
*
* @return READ ONLY string of user dir in platform-dependent notation.
*/
const char *PHYSFS_getUserDir(void);
/**
* Get the current write dir. The default write dir is NULL.
*
* @return READ ONLY string of write dir in platform-dependent notation,
* OR NULL IF NO WRITE PATH IS CURRENTLY SET.
*/
const char *PHYSFS_getWriteDir(void);
/**
* Set a new write dir. This will override the previous setting. If the
* directory or a parent directory doesn't exist in the physical filesystem,
* PhysicsFS will attempt to create them as needed.
*
* This call will fail (and fail to change the write dir) if the current
* write dir still has files open in it.
*
* @param newDir The new directory to be the root of the write dir,
* specified in platform-dependent notation. Setting to NULL
* disables the write dir, so no files can be opened for
* writing via PhysicsFS.
* @return non-zero on success, zero on failure. All attempts to open a file
* for writing via PhysicsFS will fail until this call succeeds.
* Specifics of the error can be gleaned from PHYSFS_getLastError().
*
*/
int PHYSFS_setWriteDir(const char *newDir);
/**
* Add a directory or archive to the search path. If this is a duplicate, the
* entry is not added again, even though the function succeeds.
*
* @param newDir directory or archive to add to the path, in
* platform-dependent notation.
* @param appendToPath nonzero to append to search path, zero to prepend.
* @return nonzero if added to path, zero on failure (bogus archive, dir
* missing, etc). Specifics of the error can be
* gleaned from PHYSFS_getLastError().
*/
int PHYSFS_addToSearchPath(const char *newDir, int appendToPath);
/**
* Remove a directory or archive from the search path.
*
* This must be a (case-sensitive) match to a dir or archive already in the
* search path, specified in platform-dependent notation.
*
* This call will fail (and fail to remove from the path) if the element still
* has files open in it.
*
* @param oldDir dir/archive to remove.
* @return nonzero on success, zero on failure.
* Specifics of the error can be gleaned from PHYSFS_getLastError().
*/
int PHYSFS_removeFromSearchPath(const char *oldDir);
/**
* Get the current search path. The default search path is an empty list.
*
* The returned value is an array of strings, with a NULL entry to signify the
* end of the list:
*
* char **i;
*
* for (i = PHYSFS_getSearchPath(); *i != NULL; i++)
* printf("[%s] is in the search path.\n", *i);
*
* When you are done with the returned information, you may dispose of the
* resources by calling PHYSFS_freeList() with the returned pointer.
*
* @return Null-terminated array of null-terminated strings. NULL if there
* was a problem (read: OUT OF MEMORY).
*/
char **PHYSFS_getSearchPath(void);
/**
* Helper function.
*
* Set up sane, default paths. The write dir will be set to
* "userdir/.appName", which is created if it doesn't exist.
*
* The above is sufficient to make sure your program's configuration directory
* is separated from other clutter, and platform-independent. The period
* before "mygame" even hides the directory on Unix systems.
*
* The search path will be:
*
* - The Write Dir (created if it doesn't exist)
* - The Write Dir/appName (created if it doesn't exist)
* - The Base Dir (PHYSFS_getBaseDir())
* - The Base Dir/appName (if it exists)
* - All found CD-ROM dirs (optionally)
* - All found CD-ROM dirs/appName (optionally, and if they exist)
*
* These directories are then searched for files ending with the extension
* (archiveExt), which, if they are valid and supported archives, will also
* be added to the search path. If you specified "PKG" for (archiveExt), and
* there's a file named data.PKG in the base dir, it'll be checked. Archives
* can either be appended or prepended to the search path in alphabetical
* order, regardless of which directories they were found in.
*
* All of this can be accomplished from the application, but this just does it
* all for you. Feel free to add more to the search path manually, too.
*
* @param appName Program-specific name of your program, to separate it
* from other programs using PhysicsFS.
*
* @param archiveExt File extention used by your program to specify an
* archive. For example, Quake 3 uses "pk3", even though
* they are just zipfiles. Specify NULL to not dig out
* archives automatically. Do not specify the '.' char;
* If you want to look for ZIP files, specify "ZIP" and
* not ".ZIP" ... the archive search is case-insensitive.
*
* @param includeCdRoms Non-zero to include CD-ROMs in the search path, and
* (if (archiveExt) != NULL) search them for archives.
* This may cause a significant amount of blocking
* while discs are accessed, and if there are no discs
* in the drive (or even not mounted on Unix systems),
* then they may not be made available anyhow. You may
* want to specify zero and handle the disc setup
* yourself.
*
* @param archivesFirst Non-zero to prepend the archives to the search path.
* Zero to append them. Ignored if !(archiveExt).
* @return nonzero on success, zero on error. Specifics of the error can be
* gleaned from PHYSFS_getLastError().
*/
int PHYSFS_setSaneConfig(const char *appName, const char *archiveExt,
int includeCdRoms, int archivesFirst);
/**
* Create a directory. This is specified in platform-independent notation in
* relation to the write dir. All missing parent directories are also
* created if they don't exist.
*
* So if you've got the write dir set to "C:\mygame\writedir" and call
* PHYSFS_mkdir("downloads/maps") then the directories
* "C:\mygame\writedir\downloads" and "C:\mygame\writedir\downloads\maps"
* will be created if possible. If the creation of "maps" fails after we
* have successfully created "downloads", then the function leaves the
* created directory behind and reports failure.
*
* @param dirname New dir to create.
* @return nonzero on success, zero on error. Specifics of the error can be
* gleaned from PHYSFS_getLastError().
*/
int PHYSFS_mkdir(const char *dirName);
/**
* Delete a file or directory. This is specified in platform-independent
* notation in relation to the write dir.
*
* A directory must be empty before this call can delete it.
*
* So if you've got the write dir set to "C:\mygame\writedir" and call
* PHYSFS_delete("downloads/maps/level1.map") then the file
* "C:\mygame\writedir\downloads\maps\level1.map" is removed from the
* physical filesystem, if it exists and the operating system permits the
* deletion.
*
* Note that on Unix systems, deleting a file may be successful, but the
* actual file won't be removed until all processes that have an open
* filehandle to it (including your program) close their handles.
*
* @param filename Filename to delete.
* @return nonzero on success, zero on error. Specifics of the error can be
* gleaned from PHYSFS_getLastError().
*/
int PHYSFS_delete(const char *filename);
/**
* Figure out where in the search path a file resides. The file is specified
* in platform-independent notation. The returned filename will be the
* element of the search path where the file was found, which may be a
* directory, or an archive. Even if there are multiple matches in different
* parts of the search path, only the first one found is used, just like
* when opening a file.
*
* So, if you look for "maps/level1.map", and C:\mygame is in your search
* path and C:\mygame\maps\level1.map exists, then "C:\mygame" is returned.
*
* If a any part of a match is a symbolic link, and you've not explicitly
* permitted symlinks, then it will be ignored, and the search for a match
* will continue.
*
* @param filename file to look for.
* @return READ ONLY string of element of search path containing the
* the file in question. NULL if not found.
*/
const char *PHYSFS_getRealDir(const char *filename);
/**
* Get a file listing of a search path's directory. Matching directories are
* interpolated. That is, if "C:\mydir" is in the search path and contains a
* directory "savegames" that contains "x.sav", "y.sav", and "z.sav", and
* there is also a "C:\userdir" in the search path that has a "savegames"
* subdirectory with "w.sav", then the following code:
*
* ------------------------------------------------
* char **rc = PHYSFS_enumerateFiles("savegames");
* char **i;
*
* for (i = rc; *i != NULL; i++)
* printf("We've got [%s].\n", *i);
*
* PHYSFS_freeList(rc);
* ------------------------------------------------
*
* ...will print:
*
* ------------------------------------------------
* We've got [x.sav].
* We've got [y.sav].
* We've got [z.sav].
* We've got [w.sav].
* ------------------------------------------------
*
* Feel free to sort the list however you like. We only promise there will
* be no duplicates, but not what order the final list will come back in.
*
* Don't forget to call PHYSFS_freeList() with the return value from this
* function when you are done with it.
*
* @param dir directory in platform-independent notation to enumerate.
* @return Null-terminated array of null-terminated strings.
*/
char **PHYSFS_enumerateFiles(const char *dir);
/**
* Determine if there is an entry anywhere in the search path by the
* name of (fname).
*
* Note that entries that are symlinks are ignored if
* PHYSFS_permitSymbolicLinks(1) hasn't been called, so you
* might end up further down in the search path than expected.
*
* @param fname filename in platform-independent notation.
* @return non-zero if filename exists. zero otherwise.
*/
int PHYSFS_exists(const char *fname);
/**
* Determine if the first occurence of (fname) in the search path is
* really a directory entry.
*
* Note that entries that are symlinks are ignored if
* PHYSFS_permitSymbolicLinks(1) hasn't been called, so you
* might end up further down in the search path than expected.
*
* @param fname filename in platform-independent notation.
* @return non-zero if filename exists and is a directory. zero otherwise.
*/
int PHYSFS_isDirectory(const char *fname);
/**
* Determine if the first occurence of (fname) in the search path is
* really a symbolic link.
*
* Note that entries that are symlinks are ignored if
* PHYSFS_permitSymbolicLinks(1) hasn't been called, and as such,
* this function will always return 0 in that case.
*
* @param fname filename in platform-independent notation.
* @return non-zero if filename exists and is a symlink. zero otherwise.
*/
int PHYSFS_isSymbolicLink(const char *fname);
/**
* Open a file for writing, in platform-independent notation and in relation
* to the write dir as the root of the writable filesystem. The specified
* file is created if it doesn't exist. If it does exist, it is truncated to
* zero bytes, and the writing offset is set to the start.
*
* Note that entries that are symlinks are ignored if
* PHYSFS_permitSymbolicLinks(1) hasn't been called, and opening a
* symlink with this function will fail in such a case.
*
* @param filename File to open.
* @return A valid PhysicsFS filehandle on success, NULL on error. Specifics
* of the error can be gleaned from PHYSFS_getLastError().
*/
PHYSFS_file *PHYSFS_openWrite(const char *filename);
/**
* Open a file for writing, in platform-independent notation and in relation
* to the write dir as the root of the writable filesystem. The specified
* file is created if it doesn't exist. If it does exist, the writing offset
* is set to the end of the file, so the first write will be the byte after
* the end.
*
* Note that entries that are symlinks are ignored if
* PHYSFS_permitSymbolicLinks(1) hasn't been called, and opening a
* symlink with this function will fail in such a case.
*
* @param filename File to open.
* @return A valid PhysicsFS filehandle on success, NULL on error. Specifics
* of the error can be gleaned from PHYSFS_getLastError().
*/
PHYSFS_file *PHYSFS_openAppend(const char *filename);
/**
* Open a file for reading, in platform-independent notation. The search path
* is checked one at a time until a matching file is found, in which case an
* abstract filehandle is associated with it, and reading may be done.
* The reading offset is set to the first byte of the file.
*
* Note that entries that are symlinks are ignored if
* PHYSFS_permitSymbolicLinks(1) hasn't been called, and opening a
* symlink with this function will fail in such a case.
*
* @param filename File to open.
* @return A valid PhysicsFS filehandle on success, NULL on error. Specifics
* of the error can be gleaned from PHYSFS_getLastError().
*/
PHYSFS_file *PHYSFS_openRead(const char *filename);
/**
* Close a PhysicsFS filehandle. This call is capable of failing if the
* operating system was buffering writes to this file, and (now forced to
* write those changes to physical media) can not store the data for any
* reason. In such a case, the filehandle stays open. A well-written program
* should ALWAYS check the return value from the close call in addition to
* every writing call!
*
* @param handle handle returned from PHYSFS_open*().
* @return nonzero on success, zero on error. Specifics of the error can be
* gleaned from PHYSFS_getLastError().
*/
int PHYSFS_close(PHYSFS_file *handle);
/**
* Read data from a PhysicsFS filehandle. The file must be opened for reading.
*
* @param handle handle returned from PHYSFS_openRead().
* @param buffer buffer to store read data into.
* @param objSize size in bytes of objects being read from (handle).
* @param objCount number of (objSize) objects to read from (handle).
* @return number of objects read. PHYSFS_getLastError() can shed light on
* the reason this might be < (objCount), as can PHYSFS_eof().
* -1 if complete failure.
*/
int PHYSFS_read(PHYSFS_file *handle, void *buffer,
unsigned int objSize, unsigned int objCount);
/**
* Write data to a PhysicsFS filehandle. The file must be opened for writing.
*
* @param handle retval from PHYSFS_openWrite() or PHYSFS_openAppend().
* @param buffer buffer to store read data into.
* @param objSize size in bytes of objects being read from (handle).
* @param objCount number of (objSize) objects to read from (handle).
* @return number of objects written. PHYSFS_getLastError() can shed light on
* the reason this might be < (objCount). -1 if complete failure.
*/
int PHYSFS_write(PHYSFS_file *handle, void *buffer,
unsigned int objSize, unsigned int objCount);
/**
* Determine if the end of file has been reached in a PhysicsFS filehandle.
*
* @param handle handle returned from PHYSFS_openRead().
* @return nonzero if EOF, zero if not.
*/
int PHYSFS_eof(PHYSFS_file *handle);
/**
* Determine current position within a PhysicsFS filehandle.
*
* @param handle handle returned from PHYSFS_open*().
* @return offset in bytes from start of file. -1 if error occurred.
* Specifics of the error can be gleaned from PHYSFS_getLastError().
*/
int PHYSFS_tell(PHYSFS_file *handle);
/**
* Seek to a new position within a PhysicsFS filehandle. The next read or write
* will occur at that place. Seeking past the beginning or end of the file is
* not allowed.
*
* @param handle handle returned from PHYSFS_open*().
* @param pos number of bytes from start of file to seek to.
* @return nonzero on success, zero on error. Specifics of the error can be
* gleaned from PHYSFS_getLastError().
*/
int PHYSFS_seek(PHYSFS_file *handle, int pos);
/**
* Get total length of a file in bytes. Note that if the file size can't
* be determined (since the archive is "streamed" or whatnot) than this
* with report (-1). Also note that if another process/thread is writing
* to this file at the same time, then the information this function
* supplies could be incorrect before you get it. Use with caution, or
* better yet, don't use at all.
*
* @param handle handle returned from PHYSFS_open*().
* @return size in bytes of the file. -1 if can't be determined.
*/
int PHYSFS_fileLength(PHYSFS_file *handle);
#ifdef __cplusplus
}
#endif
#endif /* !defined _INCLUDE_PHYSFS_H_ */
/* end of physfs.h ... */