System Function Native Files

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Z←L ⎕NAPPEND R appends the raveled data in L to the file whose tie number is in R.
L is an arbitrary (but simple homogeneous) array.
R is a numeric scalar or one- or two-element numeric vector.
Z is a numeric scalar of the offset in the file of the next byte after the data just appended.

The first item in R is the file tie number; the optional second element is the conversion code used to convert the data in L before writing it to the file. The File and Workspace conversion codes are as follows:

Code Name Datatype File(F) or
 110 'bool' Boolean FW
 811 'char8' 8-bit character F
1611 'char16' 16-bit character FW
3211 'char32' 32-bit character F
 812 'int8' 8-bit integer F
1612 'int16' 16-bit integer F
3212 'int32' 32-bit integer F
6412 'int64' 64-bit integer FW
6413 'flt64' 64-bit float FW

If the file conversion code is omitted, then the file conversion code specified implicitly or explicitly when the file was most recently created or opened is used.

For example:

      tn←'C:\foo' ⎕ncreate 0 ⍝ Implicit file conversion code of 'char8' and workspace conversion code of 'char16'
      'Now is the time' ⎕nappend tn

After which the file data consists of

  0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
|4E|6F|77|20|69|73|20|74|68|65|20|74|69|6D|65|20|  Now is the time

      'Now is the time' ⎕nappend tn 'char16'

After which the file data consists of

  0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
|4E|6F|77|20|69|73|20|74|68|65|20|74|69|6D|65|20|  Now is the time
|4E|00|6F|00|77|00|20|00|69|00|73|00|20|00|74|00|  N o w   i s   t
|68|00|65|00|20|00|74|00|69|00|6D|00|65|00|20|00|  h e   t i m e  

If the workspace data (in L) is wider than the width specified by the file conversion code, then a DOMAIN ERROR is signalled. For example, if the data in L is character ('char16') and the file conversion code is one of 'char8', 'int8', or 'bool', then enough of the high-order bits of each character in L must be zero so that the actual value fits without truncation.

For example:

      '⊤○⍵ ⍳⌈ ∼∆∊ ∼⍳⍦∊ ' ⎕nappend tn
      '⊤○⍵ ⍳⌈ ∼∆∊ ∼⍳⍦∊ ' ⎕nappend tn