%( $# > 1 %? if (tid() in trace) %) 是什么意思

http://blog.csdn.net/sunnybeike/article/details/7769663

http://blog.163.com/digoal@126/blog/static/16387704020139831157191/

 http://blog.163.com/digoal@126/blog/static/163877040201310194403488/

 http://blog.163.com/digoal@126/blog/static/16387704020131071118496/

 

http://blog.163.com/digoal@126/blog/static/163877040201310194403488/

 

 

$#是什么意思？（表示的是命令行中给出的参数的个数）
如果$#>1, 紧接着判断if(tid() in trace)

 

 %( CONDITION %? TRUE-TOKENS %)

 

%( CONDITION %? TRUE-TOKENS %: FALSE-TOKENS %)                          -> condition    ?   true  : false           %：预编命令

 

 

stap -e '%( CONFIG_UTRACE == "y" %? probe begin {printf("true\n"); exit();} %: probe begin {printf("false\n"); exit();} %)'