From WhitixDoc

SysOpen opens or create a file. Returns a file descriptor that can be used in later calls to SysRead, SysWrite and other filesystem calls.

Syntax

int SysOpen(
    const char* fileName,
    int flags,
    int permissions
)

Parameters

• fileName. The name of the filesystem object to be created or opened. The length of the string is limited to PATH_MAX (typically 2048) bytes by the kernel.
• flags. The following flags can be passed to the function:

Name	Value	Comments
_SYS_FILE_READ	0x0001	Open the file for reading. Some filesystem objects may be write-only (such as the Null special device) and may not permit reading.
_SYS_FILE_WRITE	0x0002	Open the file for writing. Some filesystem objects may be read-only (such as files mounted on a read-only filesystem) and may not permit writing.
_SYS_FILE_CREATE_OPEN	0x0004	Open the file, or create it if it doesn't exist. Opening a file with this option on a read-only filesystem will not succeed.
_SYS_FILE_FORCE_OPEN	0x0008	Open the file if and only if it exists.
_SYS_FILE_FORCE_CREATE	0x0010	Create the file.
_SYS_FILE_DIRECTORY	0x0020	Open the file if and only if it is a directory.

• permissions. Currently unused. Will be used in the future for filesystem permissions, but is currently ignored by the kernel.

Returns

Returns an integer of 0 or above if the filesystem object can be opened with the appropriate flags parameters.

If the filesystem object cannot be opened, one of the standard error codes will be returned.

Example

This example opens the first console device for reading and writing, assuming it already exists.

/* Open the first console device. */
int fd=SysOpen("/System/Devices/Consoles/Console0", _SYS_FILE_READ | _SYS_FILE_WRITE | _SYS_FILE_FORCE_OPEN, 0);
 
if (fd < 0)
{
    /* Failure */
}