Editing IO behaviour (section)

== 2. Console Output — scherm ==

<span id="definition"></span>
=== 2.1 Definition ===

<syntaxhighlight lang="cobol">SPECIAL-NAMES. CONSOLE IS scherm.</syntaxhighlight>
All four programs declare <code>scherm</code> as the console special-name.

<span id="structured-log-messages-via-primesui"></span>
=== 2.2 Structured Log Messages (via primesui) ===

<code>r98-message-ui</code> in primesui:

<pre>DISPLAY process-message UPON scherm</pre>
<code>process-message</code> is a 132-character group:

<pre>program-name      PIC X(20)   e.g. &quot;primesmain          &quot;
program-paragraph PIC X(20)   e.g. &quot;r90-start-session   &quot;
program-message   PIC X(92)   e.g. &quot;UI initialisation succeeded.         ...&quot;</pre>
Every caller populates <code>program-name</code>, optionally <code>program-paragraph</code>, and always <code>program-message</code> before calling <code>primesui &quot;log-message&quot;</code>.

<span id="direct-display-statements-diagnostic-error"></span>
=== 2.3 Direct DISPLAY Statements (diagnostic / error) ===

Several paragraphs bypass primesui and write directly to <code>scherm</code>:

{|
!width="33%"| Location
!width="33%"| Statement
!width="33%"| Purpose
|-
| primesmain r90
| <code>DISPLAY &quot;Emergency console message…&quot; UPON scherm</code>
| Hard abort if UI fails
|-
| primes r81
| <code>DISPLAY SQLCODE UPON scherm</code>
| SQL error on next-divider
|-
| primes r81
| <code>DISPLAY &quot;select new-divider nok&quot; UPON scherm</code>
|
|-
| primes r83
| <code>DISPLAY SQLCODE UPON scherm</code>
| SQL error on insert
|-
| primes r83
| <code>DISPLAY &quot;primes.cbl insert next prime nok…&quot; UPON scherm</code>
|
|-
| primes s00
| <code>DISPLAY &quot;connect to database&quot; UPON scherm</code>
| Always shown on connect
|-
| primes s00
| <code>DISPLAY SQLCODE UPON scherm</code>
|
|-
| primes s99
| <code>DISPLAY &quot;s99 disconnect from database&quot; UPON scherm</code>
| Always shown on disconnect
|-
| primes s99
| <code>DISPLAY SQLCODE UPON scherm</code>
|
|-
| primesui r90
| <code>DISPLAY primes-prt-status UPON scherm</code>
| File open failure
|-
| primesui r99
| <code>DISPLAY primes-prt-status UPON scherm</code>
| File close failure
|}


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<span id="database-io-primes.cbl-via-gixsql"></span>