1packfile_password(3)            Allegro manual            packfile_password(3)
2
3
4

NAME

6       packfile_password  -  Sets  the global I/O encryption password. Allegro
7       game programming library.
8

SYNOPSIS

10       #include <allegro.h>
11
12
13       void packfile_password(const char *password);
14

DESCRIPTION

16       Sets the encryption password to be used for all  read/write  operations
17       on  files  opened in future using Allegro's packfile functions (whether
18       they are compressed or not), including all the save,  load  and  config
19       routines.  Files  written  with  an  encryption password cannot be read
20       unless the same password is selected, so be careful: if you forget  the
21       key,  nobody  can make your data come back again! Pass NULL or an empty
22       string to return to the normal, non-encrypted mode. If  you  are  using
23       this  function  to  prevent people getting access to your datafiles, be
24       careful not to store an obvious copy  of  the  password  in  your  exe‐
25       cutable:  if  there  are  any  strings  like  "I'm the password for the
26       datafile", it would be fairly easy to get access to your data :-)
27
28       Note #1: when writing a packfile, you can change the password to  what‐
29       ever you want after opening the file, without affecting the write oper‐
30       ation.  On the contrary, when writing a sub-chunk of  a  packfile,  you
31       must  make  sure that the password that was active at the time the sub-
32       chunk was opened is still active before closing the sub-chunk. This  is
33       guaranteed  to  be true if you didn't call the packfile_password() rou‐
34       tine in the meantime. Read operations,  either  on  packfiles  or  sub-
35       chunks, have no such restriction.
36
37       Note  #2:  as  explained above, the password is used for all read/write
38       operations on files, including for several  functions  of  the  library
39       that   operate  on  files  without  explicitly  using  packfiles  (e.g.
40       load_bitmap()).  The unencrypted mode is mandatory in order  for  those
41       functions  to work.  Therefore remember to call packfile_password(NULL)
42       before using them if you previously changed the password. As a rule  of
43       thumb, always call packfile_password(NULL) when you are done with oper‐
44       ations on packfiles.  The only exception to this  is  custom  packfiles
45       created with pack_fopen_vtable().
46
47

SEE ALSO

49       pack_fopen(3), load_datafile(3), pack_fopen_vtable(3)
50
51
52
53Allegro                          version 4.2.3            packfile_password(3)
Impressum