Library /sys$common/syshlp/helplib.hlb  —  CRTL  creat  Arguments
 file_spec

    A null-terminated string containing any valid file specification.

 mode

    An unsigned value that specifies the file-protection mode. The
    compiler performs a bitwise AND operation on the mode and the
    complement of the current protection mode.

    You can construct modes by using the bitwise OR operator (|)  to
    create mode combinations. The modes are:

    0400   OWNER:READ
    0200   OWNER:WRITE
    0100   OWNER:EXECUTE
    0040   GROUP:READ
    0020   GROUP:WRITE
    0010   GROUP:EXECUTE
    0004   WORLD:READ
    0002   WORLD:WRITE
    0001   WORLD:EXECUTE

    The system is given the same privileges as the owner. A WRITE
    privilege implies a DELETE privilege.

                                   NOTE

       To create files with OpenVMS RMS default protections using
       the UNIX system-call functions umask, mkdir, creat, and
       open, call mkdir, creat, and open with a file-protection
       mode argument of 0777 in a program that never specifically
       calls umask. These default protections include correctly
       establishing protections based on ACLs, previous versions of
       files, and so on.

       In programs that do vfork/exec calls, the new process image
       inherits whether umask has ever been called or not from
       the calling process image. The umask setting and whether
       the umask function has ever been called are both inherited
       attributes.

  . . .

    An optional argument list of character strings of the following
    form:

    "keyword = value", . . . ,"keyword = value"

    Or in the case of "acc" or "err", this form:

    "keyword"

    Here, keyword is an RMS field in the file access block (FAB) or
    record access block (RAB); value is valid for assignment to that
    field. Some fields permit you to specify more than one value. In
    these cases, the values are separated by commas.

    The RMS callback keywords "acc" and "err" are the only keywords
    that do not take values. Instead, they are followed by a pointer
    to the callback routine to be used, followed by a pointer to a
    user-specified value to be used as the first argument of the
    callback routine. For example, to set up an access callback
    routine called acc_callback whose first argument is a pointer
    to the integer variable first_arg in a call to open, you can use
    the following statement:

    open("file.dat", O_RDONLY, 0 ,"acc", acc_callback, &first_arg)

    The second and third arguments to the callback routine must be
    pointers to a FAB and RAB, respectively, and the routine must
    have a return type of int. If the callback returns a value less
    than 0, the open, creat, or fopen fails. The error callback can
    correct the error condition and return a status greater than
    or equal to 0 to continue the creat call. Assuming the previous
    open statement, the function prototype for acc_callback would be
    similar to the following statement:

    #include <rms.h>

    int acc_callback(int *first_arg, struct FAB *fab, struct RAB *rab);

    FAB and RAB are defined in the <rms.h> header file, and the
    actual pointers passed to the routine are pointers to the RAB
    and FAB being used to open the file file.dat.

    If an access callback routine is established, then it will be
    called in the open-type routine immediately before the call to
    the RMS function sys$create or sys$open. If an error callback
    routine is established and an error status is returned from the
    sys$create or sys$open function, then the callback routine will
    be invoked immediately after the status is checked and the error
    value is discovered.

                                   NOTE

       Any manipulation of the RAB or FAB in a callback function
       could lead to serious problems in later calls to the
       Compaq C RTL I/O functions.

    RMS Valid Keywords and Values describes the RMS keywords and
    values.

    Table REF-3 RMS Valid Keywords and Values

    Keyword        Value    Description

    "acc"          callback Access callback routine.
    "alq = n"      decimal  Allocation quantity.
    "bls = n"      decimal  Block size.
    "ctx = bin"    string   No translation of '\n' to the terminal.
                            Use this for writing binary data to
                            files.
    "ctx = cvt"    string   Negates a previous setting of
                            "ctx=nocvt". This is the default.
    "ctx =         string   No conversion of Fortran carriage-control
    nocvt"                  bytes.
    "ctx = rec"    string   Forces record mode access.
    "ctx = stm"    string   Forces stream mode access.
    "ctx =         string   Causes records to be written only when
    xplct"                  explicitly specified by a call to fflush,
                            close, or fclose.
    "deq = n"      decimal  Default extension quantity.
    "dna =         string   Default file-name string.
    filespec"
    "err"          callback Error callback routine.
    "fop = val,             File-processing options:
    val , . . . "
                   ctg      Contiguous.
                   cbt      Contiguous-best-try.
                   dfw      Deferred write; only applicable to files
                            opened for shared access.
                   dlt      Delete file on close.
                   tef      Truncate at end-of-file.
                   cif      Create if nonexistent.
                   sup      Supersede.
                   scf      Submit as command file on close.
                   spl      Spool to system printer on close.
                   tmd      Temporary delete.
                   tmp      Temporary (no file directory).
                   nef      Not end-of-file.
                   rck      Read check compare operation.
                   wck      Write check compare operation.
                   mxv      Maximize version number.
                   rwo      Rewind file on open.
                   pos      Current position.
                   rwc      Rewind file on close.
                   sqo      File can only be processed in a
                            sequential manner.
    "fsz = n"      decimal  Fixed header size.
    "gbc = n"      decimal  The requested number of global buffers
                            for a file.
    "mbc = n"      decimal  Multiblock count.
    "mbf = n"      decimal  Multibuffer count.
    "mrs = n"      decimal  Maximum record size.
    "pmt=usr-      string   Prompts for terminal input. Any RMS input
    prmpt"                  from a terminal device will be preceded
                            by "usr-prmpt" when this option and
                            "rop=pmt" are specified.
    "rat = val,             Record attributes:
    val . . . "
                   cr       Carriage-return control.
                   blk      Disallow records to span block
                   ftn      boundaries.
                   none     Fortran print control.
                   prn      Explicitly forces no carriage control.
                            Print file format.
    "rfm = val"             Record format:
                   fix      Fixed-length record format.
                   stm      RMS stream record format.
                   stmlf    Stream format with line-feed terminator.
                   stmcr    Stream format with carriage-return
                            terminator.
                   var      Variable-length record format.
                   vfc      Variable-length record with fixed
                   udf      control.
                            Undefined.
    "rop = val,             Record-processing operations:
    val . . . "
                   asy      Asynchronous I/O.
                   cco      Cancels Ctrl/O (used with Terminal I/O).
                   cvt      Capitalizes characters on a read from the
                            terminal.
                   eof      Positions the record stream to the end-
                            of-file for the connect operation only.
                   nlk      Do not lock record.
                   pmt      Enables use of the prompt specified
                            by "pmt=usr-prmpt" on input from the
                            terminal.
                   pta      Eliminates any information in the type-
                            ahead buffer on a read from the terminal.
                   rea      Locks record for a read operation for
                            this process, while allowing other
                            accessors to read the record.
                   rlk      Locks record for write.
                   rne      Suppresses echoing of input data on the
                            screen as it is entered on the keyboard.
                   rnf      Indicates that Ctrl/U, Ctrl/R, and DELETE
                            are not to be considered control commands
                            on terminal input, but are to be passed
                            to the application program.
                   rrl      Reads regardless of lock.
                   syncsts  Returns a success status of RMS$_SYNCH if
                            the requested service completes its task
                            immediately.
                   tmo      Timeout I/O.
                   tpt      Allows put/write services using
                            sequential record access mode to occur
                            at any point in the file, truncating the
                            file at that point.
                   ulk      Prohibits RMS from automatically
                            unlocking records.
                   wat      Wait until record is available, if
                            currently locked by another stream.
                   rah      Read ahead.
                   wbh      Write behind.
    "rtv=n"        decimal  The number of retrieval pointers that RMS
                            has to maintain in memory (0 to 127,255).
    "shr = val,             File sharing options:
    val, . . . "
                   del      Allows users to delete.
                   get      Allows users to read.
                   mse      Allows multistream connects.
                   nil      Prohibits file sharing.
                   put      Allows users to write.
                   upd      Allows users to update.
                   upi      Allows one or more writers.
                   nql      No query locking (file level).
    "tmo = n"      decimal  I/O timeout value.

    In addition to these options, any option that takes a key value
    (such as "fop" or "rat") can be negated by prefixing the value
    with "no". For example, specify "fop=notmp" to clear the "tmp"
    bit in the "fop" field.

                                  NOTES

       o  While these options provide much flexibility and
          functionality, many of them can also cause severe
          problems if not used correctly.

       o  You cannot share the default Compaq C for OpenVMS stream
          file I/O. If you wish to share files, you must specify
          "ctx=rec" to force record access mode. You must also
          specify the appropriate "shr" options depending on the
          type of access you want.

       o  If you intend to share a file opened for append, you must
          specify appropriate share and record-locking options, to
          allow other accessors to read the record. The reason for
          doing this: the file is positioned at the end-of-file by
          reading records in a loop until end-of-file is reached.

    For more information on these options, see the OpenVMS Record
    Management Services Reference Manual.
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