Digital UNIX Diffs - open(5) Digital UNIX Diffs - open(5)NAME
open, creat - Opens a file for reading or writing
SYNOPSIS
#include <fcntl.h> #include <sys/stat.h> #include <sys/types.h>
int open (
const char *path,
int oflag [ ,
mode_t mode ] );
int creat (
const char *path,
mode_t mode );
PARAMETERS
Specifies the file to be opened or created. If the path parameter
refers to a symbolic link, the open( ) function opens the file pointed
to by the symbolic link. Specifies the type of access, special open
processing, the type of update, and the initial state of the open file.
The parameter value is constructed by logically ORing special open pro‐
cessing flags. These flags are defined in the fcntl.h header file.
Specifies the read, write, and execute permissions of the file to be
created (requested by the O_CREAT flag in the open( ) interface). If
the file already exists, this parameter is ignored. This parameter is
constructed by logically ORing values described in the sys/mode.h
header file.
DIFFERENCESvms-files(5): OpenVMS File System Differences
The syntax of filename path are different on UNIX and OpenVMS.
OpenVMS has a versioned file system. When you create a file, the next
version of the file is created; the prior version remanins intact. ON
UNIX, if you create a file with the same name as an existing file, the
existing file is lost.
Setting flag to 0777 on OpenVMS results in the default OpenVMS file
protections being used. This feature is not available on UNIX.
O_NOCTTY and O_SYNC flag values are not supported on OpenVMS.
OpenVMS supports additional arguments on open and creat calls to
describe OpenVMS RMS attributes of the file.
vms-process(5): OpenVMS Process Differences
Due to the differences in vfork(5) and exec(5) sequences on the 2 oper‐
ating systems, the state of files in the child differs between the 2
systems. File pointers are not transfered to the child on OpenVMS.
Process permanent files are not inheritted by the child either
(replaced with the null device). Both of these are transferred on
UNIX.
vms-vaxc(5): OpenVMS VAX C vs DEC C Differences
With the DEC C RTL, files containing binary data that are opened with
stream I/O must specify "ctx=bin". This is not required on VAX C RTL.
RELATED INFORMATION
Functions: creat(2), open(2)CATEGORY INDEXvms-files(5), vms-process(5), vms-vaxc(5)
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Digital UNIX Diffs - open(5)