debian man page for packfile_password

packfile_password(3alleg4)					  Allegro manual					packfile_password(3alleg4)

NAME
       packfile_password - Sets the global I/O encryption password. Allegro game programming library.

SYNOPSIS
       #include <allegro.h>

       void packfile_password(const char *password);

DESCRIPTION
       Sets the encryption password to be used for all read/write operations on files opened in future using Allegro's packfile functions (whether
       they are compressed or not), including all the save, load and config routines. Files written with an encryption	password  cannot  be  read
       unless  the  same  password  is	selected, so be careful: if you forget the key, nobody can make your data come back again! Pass NULL or an
       empty string to return to the normal, non-encrypted mode. If you are  using  this  function  to	prevent  people  getting  access  to  your
       datafiles,  be careful not to store an obvious copy of the password in your executable: if there are any strings like "I'm the password for
       the datafile", it would be fairly easy to get access to your data :-)

       Note #1: when writing a packfile, you can change the password to whatever you want after opening the  file,  without  affecting	the  write
       operation.   On	the contrary, when writing a sub-chunk of a packfile, you must make sure that the password that was active at the time the
       sub-chunk was opened is still active before closing the sub-chunk. This is guaranteed to be true if you didn't call the packfile_password()
       routine in the meantime. Read operations, either on packfiles or sub-chunks, have no such restriction.

       Note  #2:  as  explained above, the password is used for all read/write operations on files, including for several functions of the library
       that operate on files without explicitly using packfiles (e.g. load_bitmap()).  The unencrypted mode is mandatory in order for those  func-
       tions  to  work.  Therefore remember to call packfile_password(NULL) before using them if you previously changed the password. As a rule of
       thumb, always call packfile_password(NULL) when you are done with operations on packfiles.  The only exception to this is custom  packfiles
       created with pack_fopen_vtable().

SEE ALSO
       pack_fopen(3alleg4), load_datafile(3alleg4), pack_fopen_vtable(3alleg4)

Allegro 							   version 4.4.2					packfile_password(3alleg4)