EXTRACT RECORD Read-Lock Data Record

Format

EXTRACT RECORD (filespec[,fileopt])var$

Where:

filespec	Can be a numeric expression indicating the open channel number to use or a string expression containing the pathname or table name (if string is prefixed by the keyword TABLE) of the file to use.
fileopt	Supported file options (see File Options): BSY=stmtref Traps Error #0: Record/file busy DOM=stmtref Missing record transfer END=stmtref End-of-File transfer ERR=stmtref Error transfer IND=num Record index KEY=string$/num Record key KNO=num | name$ File access key number (num) or name (name$) REC=name$ Record prefix (REC=VIS(string$) can also be used) RNO=num Record number RTY=num Number of retries (one-second intervals). This overrides the value defined by the 'WT' system parameter. SIZ=num Number characters to read TBL=stmtref Data translation table TIM=num Maximum time-out value in integer seconds stmtref Program line number or statement label to which to transfer control
var$	String variable. Receives the contents of the record being read.

(TABLE support was added in PxPlus 2018.)

Description

Use the EXTRACT RECORD directive to read a record from the file you specify (channel). PxPlus will return the record's complete data portion in the string variable you specify.

Apply the EXTRACT RECORD statement when dealing with native-mode operating system files, when exchanging data with non-PxPlus applications, or when you want to read a complete record (including data field separators).

The EXTRACT RECORD directive advances the file position to the next record (or the record specified in a KEY= or IND= option). Use the KNO= option to change the current file access key.

Note:
This directive locks the record being read to prevent other users from using a FIND, FIND RECORD, READ, READ RECORD, EXTRACT RECORD or another EXTRACT RECORD to access it. This lock remains active until the next I/O request for the same file or until the file is closed.

Using a KEY= option or READ, FIND or EXTRACT statement to retrieve the next record while a record is locked will result in the locked record being returned instead.

You can enable read access for records that have been extracted by setting the 'XI' system parameter.

See Also

FIND Locate and Read Data
READ Read Data from File
KEY( ) Return Key of Next Record

Example

0010 open (1) "OLDFIL"
0020 open (2) "NEWFIL"
0030 lock (2)
0040 extract record (1,end=1000) R$
0050 write record (2) R$
0060 goto 0040
1000 close
1010 end