Processing Data Files

INPUT

Issues prompts to the screen and processes responses. The channel referenced is normally an I/O device, but an indexed file may be used.

PRINT

Formats and outputs printable data to a file, printer, or display device. This instruction also processes mnemonics and positioning information.

READ

Loads data from a file. The parameter list must contain only variables that are loaded from the record read. These receive the contents of each of the record fields in the order in which they are specified in the parameter list. See Processing Records. As an alternative to the READ directive, use FIND to read the file without moving the pointer if the record is not found. The EXTRACT directive reads the file and automatically locks the record until the next I/O operation on the channel.

FIND

Reads data from a file where data is split into fields (separated by current delimiter or defined by embedded format, headers, etc.), with the contents of the first field placed in variable 1, the second into variable 2, and so on. See Processing Records.

EXTRACT

Reads data from file where data is split into fields (separated by current delimiter or defined by current delimiter or in an embedded IOList format), with the contents of the first field placed in variable 1, the second into variable 2, and so on. This locks the record until the next I/O operation on the channel. See Processing Records.

WRITE

Writes a record to a file. In the case of indexed or keyed files, this may rewrite existing records. The values specified in the parameter list are written into consecutive fields, each separated by a field separator (Hex $8A$) or formatted as per format specifications in the list. See Processing Records.

REMOVE

Deletes a record from a keyed file. No parameter list required.

BSY=stmtref

Statement number to transfer to if the record is currently locked by another process.

DOM=stmtref

Indicates the statement number (stmtref) to transfer to if the record referenced by the directive is either missing (in the case of READ) or already exists (on WRITE).

END=stmtref

Traps the end of the file on a READ (Error #2: END-OF-FILE on read or File full on write). On a WRITE directive, causes a transfer if the output file has reached its maximum size or no more file space is available.

ERR=stmtref

Indicates the statement (stmtref) to transfer to if an error occurs during processing of the directive.

IND=num

Specifies record index value used to uniquely identify a record in indexed and keyed files.

For fixed length keyed files, num represents an offset into the data file (first record has an index of 0, second is 1, and so on).

For variable length keyed files, num represents a logical page address and record index within that page. Used with the INPUT directive, IND=num sets the starting position (column number) of the cursor in the input field. When processing a file in Binary mode via the ISZ= option, IND=num identifies the record address to access when the file is opened.

KEY=string$

Specifies the record key value used to uniquely identify a record.

LEN=num

Limits the length of the input data. If this option is specified in an INPUT statement, only the number of characters specified by num will be read.

KNO=num | name$

Access key number (num) or name (name$), where num is 0 based (0 - 15 for VLR/FLR files; 0 - 255 for EFF files).

RNO=num

Specifies the record number within the file based on actual key sequence position; first record in the file is RNO#1.