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More updates, corrections, clarifications...

This commit is contained in:
Ryan C. Gordon 2001-07-05 08:19:01 +00:00
parent 745aaae8b2
commit 74637e4842
1 changed files with 169 additions and 103 deletions
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physfs.h
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@ -13,18 +13,18 @@
* fs_* cvars. If you've ever tinkered with these, then this API will be
* familiar to you.
*
* With PhysicsFS, you have a single writing path and multiple "search paths"
* 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 path to "C:\", but
* that's generally A Bad Thing for several reasons.
* 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 paths create a single, hierarchical directory structure.
* 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
@ -32,25 +32,26 @@
* 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 path 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 path
* 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 and search paths; after that, all
* file access into those paths are done with platform-independent notation.
* "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 path,
* 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 it's internal search path. This is NOT the
* 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 a search path is defined, you may open files for reading. If you've
* 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
@ -58,7 +59,7 @@
* D:\mygamescdromdatafiles
* C:\mygame\installeddatafiles.zip
*
* Then a call to PHYSFS_openread("textfiles/myfile.txt") (note the directory
* 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
@ -68,37 +69,53 @@
* 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 ".." as path
* elements. Not only are these meaningless on MacOS, 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 and search
* paths. There is no mechanism for creating new symlinks in PhysicsFS.
* 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 path is not included in the search path unless you specifically
* add it. While you CAN change the write path as many times as you like,
* you should probably set it once and stick to that path. Remember that
* your program will not have permission to write in every directory on
* Unix and NT systems.
* 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 path separator ("\\" on windows, "/" on Unix, ":" on MacOS),
* 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 a search path is the write path, then the base path,
* then the cdrom path, then any archives discovered. Quake 3 does something
* 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 path for both searching and writing. There is a helper
* function (PHYSFS_setSanePaths()) that puts together a basic configuration
* 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_getBasePath(), and PHYSFS_getUserPath() for info on what those
* are and how they can help you determine an optimal searchpath.
* 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
@ -127,7 +144,7 @@ extern "C" {
typedef struct __PHYSFS_FILE__
{
unsigned int opaque;
void *opaque;
} PHYSFS_file;
typedef struct __PHYSFS_ARCHIVEINFO__
@ -139,6 +156,46 @@ typedef struct __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 0
#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.
@ -157,6 +214,8 @@ int PHYSFS_init(const char *argv0);
* Once deinitialized, PHYSFS_init() can be called again to restart the
* subsystem.
*
* This function can be used with atexit(), if you feel it's prudent to do so.
*
* @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.
@ -171,8 +230,8 @@ void PHYSFS_deinit(void);
* 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 strings, with a NULL entry to signify the
* end of the list:
* 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;
*
@ -187,7 +246,7 @@ void PHYSFS_deinit(void);
*
* @return READ ONLY Null-terminated array of READ ONLY structures.
*/
const PHYSFS_ArchiveInfo *PHYSFS_supportedArchiveTypes(void);
const PHYSFS_ArchiveInfo **PHYSFS_supportedArchiveTypes(void);
/**
@ -202,8 +261,11 @@ 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.
* 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.
*/
@ -211,24 +273,24 @@ const char *PHYSFS_getLastError(void);
/**
* Get a platform-dependent path separator. This is "\\" on win32, "/" on Unix,
* 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
* paths always use '/' (platform-independent notation) to separate
* 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 path separator.
* @return READ ONLY null-terminated string of platform's dir separator.
*/
const char *PHYSFS_getPathSeparator(void);
const char *PHYSFS_getDirSeparator(void);
/**
* Get an array of paths to available CD-ROM drives.
* Get an array of dirs to available CD-ROM drives.
*
* The paths returned are platform-dependent ("D:\" on Win32, "/cdrom" or
* whatnot on Unix). Paths are only returned if there is a disc ready and
* 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
@ -240,8 +302,8 @@ const char *PHYSFS_getPathSeparator(void);
*
* char **i;
*
* for (i = PHYSFS_getCdRomPaths(); *i != NULL; i++)
* printf("cdrom path [%s] is available.\n", *i);
* for (i = PHYSFS_getCdRomDirs(); *i != NULL; i++)
* printf("cdrom dir [%s] is available.\n", *i);
*
* This call may block while drives spin up. Be forewarned.
*
@ -250,82 +312,82 @@ const char *PHYSFS_getPathSeparator(void);
*
* @return Null-terminated array of null-terminated strings.
*/
char **PHYSFS_getCdRomPaths(void);
char **PHYSFS_getCdRomDirs(void);
/**
* Helper function.
*
* Get the "base path". This is the directory where the application was run
* 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 path in your search path.
* You should probably use the base dir in your search path.
*
* @return READ ONLY string of base path in platform-dependent notation.
* @return READ ONLY string of base dir in platform-dependent notation.
*/
const char *PHYSFS_getBasePath(void);
const char *PHYSFS_getBaseDir(void);
/**
* Helper function.
*
* Get the "user path". This is meant to be a suggestion of where a specific
* 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:\mybasepath\users\username"
* 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 path as the basis for your write path, and
* 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 path in platform-dependent notation.
* @return READ ONLY string of user dir in platform-dependent notation.
*/
const char *PHYSFS_getUserPath(void);
const char *PHYSFS_getUserDir(void);
/**
* Get the current write path. The default write path is NULL.
* Get the current write dir. The default write dir is NULL.
*
* @return READ ONLY string of write path in platform-dependent notation,
* @return READ ONLY string of write dir in platform-dependent notation,
* OR NULL IF NO WRITE PATH IS CURRENTLY SET.
*/
const char *PHYSFS_getWritePath(char *buffer, int bufferSize);
const char *PHYSFS_getWriteDir(void);
/**
* Set a new write path. This will override the previous setting. If the
* 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 path) if the current path
* still has files open in it.
* This call will fail (and fail to change the write dir) if the current
* write dir still has files open in it.
*
* @param newPath The new directory to be the root of the write path,
* @param newDir The new directory to be the root of the write dir,
* specified in platform-dependent notation. Setting to NULL
* disables the write path, so no files can be opened for
* 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_setWritePath(const char *newPath);
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 newPath directory or archive to add to the path, in
* @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, path
* @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 *newPath, int appendToPath);
int PHYSFS_addToSearchPath(const char *newDir, int appendToPath);
/**
@ -337,11 +399,11 @@ int PHYSFS_addToSearchPath(const char *newPath, int appendToPath);
* This call will fail (and fail to remove from the path) if the element still
* has files open in it.
*
* @param oldPath dir/archive to remove.
* @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 *oldPath);
int PHYSFS_removeFromSearchPath(const char *oldDir);
/**
@ -358,7 +420,8 @@ int PHYSFS_removeFromSearchPath(const char *oldPath);
* 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.
* @return Null-terminated array of null-terminated strings. NULL if there
* was a problem (read: OUT OF MEMORY).
*/
char **PHYSFS_getSearchPath(void);
@ -366,8 +429,8 @@ char **PHYSFS_getSearchPath(void);
/**
* Helper function.
*
* Set up sane, default paths. The write path will be set to
* "userpath/.appName", which is created if it doesn't exist.
* 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
@ -375,12 +438,12 @@ char **PHYSFS_getSearchPath(void);
*
* The search path will be:
*
* - The Write Path (created if it doesn't exist)
* - The Write Path/appName (created if it doesn't exist)
* - The Base Path (PHYSFS_getBasePath())
* - The Base Path/appName (if it exists)
* - All found CD-ROM paths (optionally)
* - All found CD-ROM paths/appName (optionally, and if they exist)
* - 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
@ -412,23 +475,23 @@ char **PHYSFS_getSearchPath(void);
* @param archivesFirst Non-zero to prepend the archives to the search path.
* Zero to append them. Ignored if !(archiveExt).
*/
void PHYSFS_setSanePaths(const char *appName, const char *archiveExt,
int includeCdRoms, int archivesFirst);
void 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 path. All missing parent directories are also
* relation to the write dir. All missing parent directories are also
* created if they don't exist.
*
* So if you've got the write path set to "C:\mygame\writepath" and call
* So if you've got the write dir set to "C:\mygame\writedir" and call
* PHYSFS_mkdir("downloads/maps") then the directories
* "C:\mygame\writepath\downloads" and "C:\mygame\writepath\downloads\maps"
* "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 path to create.
* @param dirname New dir to create.
* @return nonzero on success, zero on error. Specifics of the error can be
* gleaned from PHYSFS_getLastError().
*/
@ -437,13 +500,13 @@ int PHYSFS_mkdir(const char *dirName);
/**
* Delete a file or directory. This is specified in platform-independent
* notation in relation to the write path.
* 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 path set to "C:\mygame\writepath" and call
* 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\writepath\downloads\maps\level1.map" is removed from the
* "C:\mygame\writedir\downloads\maps\level1.map" is removed from the
* physical filesystem, if it exists and the operating system permits the
* deletion.
*
@ -500,15 +563,15 @@ void PHYSFS_permitSymbolicLinks(int allow);
* @return READ ONLY string of element of search path containing the
* the file in question. NULL if not found.
*/
const char *PHYSFS_getRealPath(const char *filename);
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:\mypath" is in the search path and contains a
* 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:\userpath" in the search path that has a "savegames"
* there is also a "C:\userdir" in the search path that has a "savegames"
* subdirectory with "w.sav", then the following code:
*
* ------------------------------------------------
@ -530,18 +593,21 @@ const char *PHYSFS_getRealPath(const char *filename);
* 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 path directory in platform-independent notation to enumerate.
* @param dir directory in platform-independent notation to enumerate.
* @return Null-terminated array of null-terminated strings.
*/
char **PHYSFS_enumerateFiles(const char *path);
char **PHYSFS_enumerateFiles(const char *dir);
/**
* Open a file for writing, in platform-independent notation and in relation
* to the write path as the root of the writable filesystem. The specified
* 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.
*
@ -554,7 +620,7 @@ PHYSFS_file *PHYSFS_openWrite(const char *filename);
/**
* Open a file for writing, in platform-independent notation and in relation
* to the write path as the root of the writable filesystem. The specified
* 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.