__set_fd_properties

Syntax

#include <libc/fd_props.h> int __set_fd_properties(int fd, const char *filename, int open_flags);

Description

This is an internal function that stores information about the file descriptor fd in a fd_properties struct. It is called by open and its helper functions.

The file name stored in fd_properties is the result of the _truename function (see section _truename) on filename. The open_flags are scanned and the temporary and append flags are stored in the flags field in fd_properties.

struct fd_properties { unsigned char ref_count; char *filename; unsigned long flags; fd_properties *prev; fd_properties *next; };

flags can contain a combination of bits:

FILE_DESC_TEMPORARY

Delete filename when ref_count becomes zero.

FILE_DESC_ZERO_FILL_EOF_GAP

Tell write and _write to test for file offset greater than EOF. Set by lseek and llseek.

FILE_DESC_DONT_FILL_EOF_GAP

Don't test for the EOF gap. Set automatically for stdin, stdout, and NUL. Can also be set by an FSEXT.

FILE_DESC_PIPE

The file descriptor is used in emulating a pipe.

FILE_DESC_APPEND

The file pointer will be set to the end of file before each write.

FILE_DESC_DIRECTORY

The file descriptor is for a directory.

The flags can be manipulated using __set_fd_flags (see section __set_fd_flags), __clear_fd_flags (see section __clear_fd_flags) and __get_fd_flags (see section __get_fd_flags).

The file name can be retrieved using __get_fd_name (see section __get_fd_name).

For more information, see __clear_fd_properties (see section __clear_fd_properties) and __dup_fd_properties (see section __dup_fd_properties).

Return Value

Returns 0 on success. Returns -1 when unable to store the information.

Portability

ANSI/ISO C	No
POSIX	No