What are the different file open modes in Cobol?

File open in following modes:

• Input – This mode is used for existing files.
• Output – File is used only for writing, i.e to insert a record in the file.
• Extend – To append records in a sequential file extend mode is used, i.e records are inserted at the end.

How many types of access modes are there?

There are three ways to access a file into a computer system: Sequential-Access, Direct Access, Index sequential Method.

What is difference between dynamic and random access in Cobol?

random access mean you randomly locate the record using RBA for ESDS , RRN for RRDS and Primary key for KSDS and your search goes record by record. dynamic access means you dynamically locate a record and from there you perform sequential operation.

How do I open a Cobol file?

PROCEDURE DIVISION. OPEN INPUT STUDENT. PERFORM UNTIL WS-EOF=’Y’ READ STUDENT INTO WS-STUDENT AT END MOVE ‘Y’ TO WS-EOF NOT AT END DISPLAY WS-STUDENT END-READ END-PERFORM. CLOSE STUDENT.

Which of the following file opening mode is invalid in COBOL?

Explanation. Valid file opening modes in COBOL are INPUT, OUTPUT, I-O, and EXTEND. APPEND file mode is not available in COBOL.

What is IO mode in COBOL?

I-O. Input-Output mode is used to read and rewrite the records of a file.

What is access mode for start statement in Cobol?

START is used to set the file pointer to read the next record. The START statement used for positioning within an indexed or relative file for subsequent sequential retrieval. The associated indexed or relative file must be open in either INPUT or I-O mode before performing START statement.

What are the different access methods used to access the data stored in memory?

Storage access methods BSAM – Basic sequential access method. QSAM – Queued sequential access method. BPAM – Basic partitioned access method. ISAM – Indexed sequential access method.

What are the different modes of file?

There are many modes for opening a file:

• r – open a file in read mode.
• w – opens or create a text file in write mode.
• a – opens a file in append mode.
• r+ – opens a file in both read and write mode.
• a+ – opens a file in both read and write mode.
• w+ – opens a file in both read and write mode.

What is extend mode in Cobol?

Extend mode is used to append records in a sequential file. In this mode, records are inserted at the end. If file access mode is Random or Dynamic, then extend mode cannot be used.

What does C stand in COBOL?

If COBOL stands for “Common Business-Oriented Language,” and C stands for Common, shouldn’t the O stand for something as well?