dosopen

Purpose

     Opens a DOS file.

Library

     DOS Services Library (libdos.a)

Syntax

     #include <dos.h>

     DOSFILE dosopen (path, oflag, mode)
     char *path;
     int oflag;
     long mode;

Description

     The dosopen  subroutine opens  the file specified  by the
     path parameter.   The oflag parameter specifies  the type
     of open.  The mode parameter specifies the access mode of
     the file if a new file is created.

     The oflag  parameter is  constructed by  logically OR-ing
     one or more of the following values:

     DO_RDONLY    Open for reading only.

     DO_WRONLY    Open for writing only.

     DO_RDWR      Open for reading and writing.

     DO_APPEND    If set, the  file pointer is set  to the end
                  of the file prior to each write operation.

     DO_CREAT     If the file does  not exist, create it.  Use
                  mode to establish the protection mode of the
                  new  file.  (For  information on  creating a
                  DOS file, see "doscreate.")

     DO_TRUNC     If the file  exists, truncate it.  Otherwise
                  begin writing at the end of file.

     DO_EXCL      If the file already exists, the dosopen sub-
                  routine fails.

     DO_ASCII     Interpret the  file as  an ASCII  text file.
                  (For  information  about  ASCII  files,  see
                  "dosread" and "doswrite.")

     Note:  Only one of  DO_RDONLY, DO_WRONLY, and DO_RDWR can
     be specified.  The others can be used in any combination.

     If the  file being opened  is on  a DOS file  system, the
     name file name given is  translated to uppercase.  If the
     file system is  an AIX file system,  no translation takes
     place.

     Warning:   DOS files  are  not implicitly  closed when  a
     process terminates.   You must  explicitly close  all DOS
     files or you may lose data.

Return Value

     Upon successful completion, a DOS Services file handle is
     returned.  This handle is  used in subsequent operations.
     If the dosopen subroutine fails, -1 value is returned and
     doserrno is set to indicate the error.

Related Information

     In  this  book:   "DOS  services  library,"  "dosclose,"
     "doscreate,"  "dosdup,"      "dosread,"  "dosseek,"  and
     "doswrite."