Chapter 9 Reading from a File

Table of Contents

Sequential Access and Random Access

Reading from a disk file using sequential access

Reading from a disk file using random access

Increasing I/O performance using FREADSEEK

Reading From $STDIN

Reading From a Magnetic Tape File

Reading a File Label from a Labeled Tape File

• "Sequential Access and Random Access" discusses two common methods of record selection and data transfer, and uses examples to illustrate the use of the FREAD and FREADDIR intrinsics.

• "Reading from $STDIN" discusses how your program can use the READ, READX, and FREAD intrinsics to read data from the job/session standard input device, $STDIN. An example illustrates the use of the READ intrinsic to read a character string from $STDIN.

• "Reading from a Magnetic Tape File" provides an example of using the FREAD intrinsic to read data from file located on magnetic tape.

• "Reading a File Label from a Labeled Tape File" provides an example of using the FREADLABEL intrinsic to read a user-defined file label located on a labeled magnetic tape file.