Documentación de Gambas - GB_STREAM

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GB_STREAM_DESC

struct GB_STREAM;

typedef
  struct {
    int (*open)(struct GB_STREAM *stream, const char *path, int mode, void *data);
    int (*close)(struct GB_STREAM *stream);
    int (*read)(struct GB_STREAM *stream, char *buffer, long len);
    int (*write)(struct GB_STREAM *stream, char *buffer, long len);
    int (*seek)(struct GB_STREAM *stream, long long pos, int whence);
    int (*tell)(struct GB_STREAM *stream, long long *pos);
    int (*flush)(struct GB_STREAM *stream);
    int (*eof)(struct GB_STREAM *stream);
    int (*lof)(struct GB_STREAM *stream, long long *len);
    int (*handle)(struct GB_STREAM *stream);
    }
GB_STREAM_DESC;

This describe is a function pointer table that must point at the implementation functions of a Flujo.

Each Flujo has a pointer to such a structure. See GB_STREAM for more details.

Function	What should be done	What should be returned
`open`	Opens the Flujo. This function is never called directly by the interpreter, as you must open the file yourself, by instanciating the Stream Gambas object, and by filling the GB_STREAM structure appropriately.	`TRUE` if the Flujo cannot be opened, and `FALSE` if everything is OK.
`close`	Closes the Flujo.	`FALSE`.
`read`	Reads len bytes into the Flujo, and fills the buffer with them.	`TRUE` if there was an error, and `FALSE` if everything is OK. The `errno` code is used by the interpreter to choose the error message.
`write`	Writes the len bytes located at buffer to the Flujo.	`TRUE` if there was an error, and `FALSE` if everything is OK. The `errno` code is used by the interpreter to choose the error message.
`seek`	Seeks into the Flujo. pos is the position inside the Flujo. whence is one the following constants: `SEEK_SET`, to indicate that pos is an absolute position. `SEEK_CUR`, to indicate that pos is an offset to the current position. `SEEK_END`, to indicate that pos is an offset from the end of the Flujo.	`TRUE` if seeking is impossible, and `FALSE` if everything is OK.
`tell`	Returns the current Flujo position in pos.	`TRUE` if seeking is impossible, and `FALSE` if everything is OK.
`flush`	Flushes the Flujo.	`TRUE` if there was an error, and `FALSE` if everything is OK. If flushing has no sense for your Flujo, then you must return `FALSE`.
`eof`	Checks the end of the Flujo.	`TRUE` if the end of the Flujo is reached, `FALSE` otherwise.
`lof`	Returns in len the length of the Flujo. If this has no sense for your Flujo, and if the `handle` function returns a system file descriptor, you can let the interpreter returns the maximum number of bytes that can be read on the Flujo for you, by putting `0` in len.	`FALSE`.
`handle`	Returns the underlying system file descriptor.	The underlying system file descriptor.

Véase también

api/cat/stream