RLn: Difference between revisions

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  RLn(N[,X])
  RLn(N[,X])


The '''RLn''' [[internal function]] returns the [[record length]] of an open [[file handle]] N. The optional X parameter may be used with external files only to shorten the record length to the specified amount.
The '''RLn''' [[internal function]] returns the [[record length]] of an open [[file handle]] N. The optional X parameter may be used only with external files to reset the record length to the specified amount. The new record length cannot exceed the original record length specified in the OPEN statement.  


====Comments and Examples====
====Comments and Examples====
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Here are three quick steps to determine the record length of an internal file:
Here are three quick steps to determine the record length of an internal file:


  00100 OPEN #1:"name=filename",I,I,S
  00100 OPEN #1:"name=filename",Internal,Input,Sequential
  00200 PRINT RLN(1)
  00200 PRINT RLN(1)
  00300 END
  00300 END


The number printed by PRINT RLN(1) is the record length for file 1. The END statement is a short way to close any open files.
The number printed by PRINT RLN(1) is the record length for file 1. The file will be closed when the END statement is processed.
 
In the following example, RLN shortens the record length of file 1 to 128 bytes. It is important to note that '''RLN can only shorten''', not lengthen, external file record lengths.


In the following example, RLN shortens the record length of file 1 to 128 bytes.
  10 LET RLN(1,128)
  10 LET RLN(1,128)



Revision as of 14:26, 18 December 2013

RLn(N[,X])

The RLn internal function returns the record length of an open file handle N. The optional X parameter may be used only with external files to reset the record length to the specified amount. The new record length cannot exceed the original record length specified in the OPEN statement.

Comments and Examples

Here are three quick steps to determine the record length of an internal file:

00100 OPEN #1:"name=filename",Internal,Input,Sequential
00200 PRINT RLN(1)
00300 END

The number printed by PRINT RLN(1) is the record length for file 1. The file will be closed when the END statement is processed.

In the following example, RLN shortens the record length of file 1 to 128 bytes.

10 LET RLN(1,128)

Related Functions

For additional information about external file record lengths, see the POS= and REC= parameters for the READ file statement.

For additional information about files, see the following: