diff options
Diffstat (limited to 'stap.1.in')
| -rw-r--r-- | stap.1.in | 17 |
1 files changed, 6 insertions, 11 deletions
@@ -467,12 +467,11 @@ For prologue style alias, the statement block that follows an alias definition is implicitly added as a prologue to any probe that refers to the alias. While for the epilogue style alias, the statement block that follows an alias definition is implicitly added as an epilogue to -any probe that refers to the alias. For example: +any probe that refers to the alias. For example: .SAMPLE probe syscall.read = kernel.function("sys_read") { fildes = $fd - if (execname == "init") next # skip rest of probe } .ESAMPLE defines a new probe point @@ -483,23 +482,19 @@ which expands to .nh .IR kernel.function("sys_read") , .hy -with the given statement as a prologue, which is useful to predefine -some variables for the alias user and/or to skip probe processing -entirely based on some conditions. And +with the given statement as a prologue. And .SAMPLE probe syscall.read += kernel.function("sys_read") { - if (tracethis) println ($fd) + fildes = $fd } .ESAMPLE -defines a new probe point with the given statement as an epilogue, which -is useful to take actions based upon variables set or left over by the -the alias user. +defines a new probe point with the given statement as an epilogue. -An alias is used just like a built-in probe type. +Another probe definition +may use the alias like this: .SAMPLE probe syscall.read { printf("reading fd=%d\n", fildes) - if (fildes > 10) tracethis = 1 } .ESAMPLE |