IBM AIX Continuous Availability Features - IBM Redbooks

Structure of a Vue script
A Vue script consists of one or more clauses. The clauses in a Vue script can be specified in
any order. Figure 3-3 is a typical layout of a Vue script.
Figure 3-3 Structure of a Vue script
Following are two Vue script examples.
► This canonical “Hello World” program prints "Hello World" into the trace buffer and exits.
#!/usr/bin/probevue
/* Hello World in probevue */
/* Program name: hello.e */
@@BEGIN
{
printf("Hello World\n");
exit();
}
► This “Hello World” program prints "Hello World" when is typed on the keyboard.
#!/usr/bin/probevue
/* Hello World 2 in probevue */
/* Program name: hello2.e */
@@END
{
printf("Hello World\n");
}
Each clause of a Vue script consists of the following three elements:
► Probe point specification
The probe point specification identifies the probe points to be dynamically enabled.
► Action block
The action block is used to identify the set of probe actions to be performed when the
probe fires.
Chapter 3. AIX advanced continuous availability tools and features 115