fp_open Kernel Service

Purpose

Opens special and regular files or directories.

Syntax

#include <sys/types.h>
#include <sys/errno.h>

int fp_open (path,oflags,mode,ext,segflag,fpp)
char * path;
long  oflags;
int  mode;
ext_t  ext;
int  segflag;
struct file ** fpp;          
                                                                                              
                                  

Parameters

Item Description
path Points to the file name of the file to be opened.
oflags Specifies open mode flags as described in the open subroutine.
mode Specifies the mode (permissions) value to be given to the file if the file is to be created.
ext Specifies an extension argument required by some device drivers. Individual drivers determine its content, form, and use.
segflag Specifies the flag indicating where the pointer specified by the path parameter is located:
SYS_ADSPACE
The pointer specified by the path parameter is stored in kernel memory.
USER_ADSPACE
The pointer specified by the path parameter is stored in application memory.
fpp Points to the location where the file structure pointer is to be returned by the fp_open service.

Description

The fp_open kernel service provides a common service used by:

Execution Environment

The fp_open kernel service can be called from the process environment only.

Return Values

Item Description
0 Indicates a successful operation.

Also, the fpp parameter points to an open file structure that is valid for use with the other Logical File System services. If an error occurs, one of the values from the /usr/include/sys/errno.h file is returned. The discussion of the open subroutine contains possible errno values.