Table of Contents
The BEGIN
probe fires before any other probe. No other probe will fire until all BEGIN
clauses have completed. This probe can be used to initialize any state that is needed in other probes. The following example shows how to use the BEGIN
probe to initialize an associative array to map between
mmap
(
2
)
protection bits and a textual representation:
BEGIN { prot[0] = "---"; prot[1] = "r--"; prot[2] = "-w-"; prot[3] = "rw-"; prot[4] = "--x"; prot[5] = "r-x"; prot[6] = "-wx"; prot[7] = "rwx"; } syscall::mmap:entry { printf("mmap with prot = %s", prot[arg2 & 0x7]); }
The BEGIN
probe fires in an unspecified context. This means that the output of stack
or ustack
, and the value of context-specific variables (for example, execname
), are all arbitrary. These values should not be relied upon or interpreted to infer any meaningful information. No arguments are defined for the BEGIN
probe.