Host Environment Commands › ADDRESS EPI Commands › EPI PEEK—Display Screen Buffer in Hexadecimal

EPI PEEK—Display Screen Buffer in Hexadecimal

The EPI PEEK command displays the contents of the virtual terminal screen buffer in hexadecimal format. EPI displays 16 hexadecimal bytes for each output line except for row 0 of the screen. PEEK under EPI does not read the contents of row 0.

Usually, you issue this command to interrogate 3278 host attribute bytes. The PEEK command runs in AOF rules synchronously and returns data to the external data queue. The command returns buffer code in EBCDIC format; values ranging from X'20' through X'3F' are attribute bytes. You can read the screen more easily using the EPI RDSCREEN and EPI RDSCRROW commands.

EPI PEEK has the following format:

ADDRESS EPI "PEEK keywords"

/* You must specify a value for each keyword.   */
{termname|*}
{row}
{col}
{length}

termname

Defines the virtual terminal for which you want to display buffer contents.

*

Specifies the current terminal that is defined through the SETTERM command.

row

Identifies the number of the screen row where capturing of buffer contents begins.

col

Identifies the number of the screen column where capturing of buffer contents begins.

length

Defines the number of lines from the screen buffer that you want to display.

EPI PEEK Sample Coding Statements

The following sample coding statement issues this PEEK command:

PEEK TERM4 22 1 30

You receive the following output:

24 D9 C5 C1 C4 E8 20 00 00 00 00 00 00 00 00 00 *.READY..........*
00 00 00 00 00 00 00 00 00 00 00 00 00 00

This example shows the beginning of the TSO READY message on terminal TERM4. The first number, 24, is a high-intensity unprotected attribute byte. The five characters following it are READY in 3278 buffer code. The number following that, 20, is a low-intensity unprotected attribute byte.