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File Create {R}←X ⎕FCREATE Y

Y must be a simple integer scalar or a 1 or 2 element vector:

  • The first element is the file tie number. The file tie number must not be the tie number associated with another tied file.
  • The second element, if specified, must be 64.

Legacy

The second element of Y sets the span of the file which in earlier versions of Dyalog could be 32 or 64. Small-span (32-bit) component files can no longer be created; this element is retained for backwards compatibility purposes.

X must be either:

  1. a simple character scalar or vector which specifies the name of the file to be created. If no file extension is supplied, the first extension specified by the   CFEXT parameter will be added. See  CFEXT.
  2. a vector of length 1 or 2 whose items are:- a simple character scalar or vector as above.
  3. an integer scalar specifying the file size limit in bytes.

The newly created file is tied for exclusive use.

The shy result of ⎕FCREATE is the tie number of the new file.

Automatic Tie Number Allocation

A tie number of 0 as argument to a create or tie operation, allocates, and returns as an explicit result, the first (closest to zero) available tie number. This allows you to simplify code. For example:

from: 


      tie←1+⌈/0,⎕FNUM     ⍝ With next available number,
      file ⎕FCREATE tie   ⍝ ... create file.

to: 


      tie←file ⎕FCREATE 0 ⍝ Create with first available..

Examples


      '..\BUDGET\SALES'    ⎕FCREATE 2    ⍝ Windows
      '../budget/SALES.85' ⎕FCREATE 2    ⍝ UNIX

      'COSTS' 200000 ⎕FCREATE 4         ⍝ max size 200000

File Properties

⎕FCREATE allows you to specify properties for the newly created file via the variant operator ⍠ used with the following options:

  • 'J' - journaling level; a numeric value
  • 'C' - checksum level; 0 or 1
  • 'Z' - compression; 0 or 1
  • 'U' - Unicode; 0 or 1
  • 'S' - File Size (span); 64

The Principal Option is as follows:

  • 0 - sets ('J' 0) ('C' 0)
  • 1 - sets ('J' 1) ('C' 1)
  • 2 - sets ('J' 2) ('C' 1)
  • 3 - sets ('J' 3) ('C' 1)

See also: File Properties .

Examples

      'newfile' (⎕FCREATE⍠3) 0
1
      'SEUJCZ' ⎕FPROPS 1
64 0 1 3 1 0

Alternatively: 

      JFCREATE←⎕FCREATE ⍠ 3

will name a variant of ⎕FCREATE which will create component file with level 3 journaling, and checksum enabled. Then: 

      'newfile'JFCREATE 0
1

Information

Component files that have both journalling and checksum properties set to 0 have been deprecated, and it is no longer possible to create files with this combination of properties. For information on how to identify code that creates component files that have both journalling and checksum properties set to 0 in your existing codebase, see the Release Notes.

⎕FCREATE FCREATE