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ALLEGRO_FILE_INTERFACE(3) | ALLEGRO_FILE_INTERFACE(3) |
NAME¶
ALLEGRO_FILE_INTERFACE - Allegro 5 API
SYNOPSIS¶
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#include <allegro5/allegro.h> typedef struct ALLEGRO_FILE_INTERFACE
DESCRIPTION¶
A structure containing function pointers to handle a type of “file”, real or virtual. See the full discussion in al_set_new_file_interface(3).
The fields are:
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void* (*fi_fopen)(const char *path, const char *mode); bool (*fi_fclose)(ALLEGRO_FILE *f); size_t (*fi_fread)(ALLEGRO_FILE *f, void *ptr, size_t size); size_t (*fi_fwrite)(ALLEGRO_FILE *f, const void *ptr, size_t size); bool (*fi_fflush)(ALLEGRO_FILE *f); int64_t (*fi_ftell)(ALLEGRO_FILE *f); bool (*fi_fseek)(ALLEGRO_FILE *f, int64_t offset, int whence); bool (*fi_feof)(ALLEGRO_FILE *f); int (*fi_ferror)(ALLEGRO_FILE *f); const char * (*fi_ferrmsg)(ALLEGRO_FILE *f); void (*fi_fclearerr)(ALLEGRO_FILE *f); int (*fi_fungetc)(ALLEGRO_FILE *f, int c); off_t (*fi_fsize)(ALLEGRO_FILE *f);
The fi_open function must allocate memory for whatever userdata structure it needs. The pointer to that memory must be returned; it will then be associated with the file. The other functions can access that data by calling al_get_file_userdata(3) on the file handle. If fi_open returns NULL then al_fopen(3) will also return NULL.
The fi_fclose function must clean up and free the userdata, but Allegro will free the ALLEGRO_FILE(3) handle.
If fi_fungetc is NULL, then Allegro’s default implementation of a 16 char long buffer will be used.
Allegro reference manual |