opentrace.bt

#!/usr/bin/env bpftrace


tracepoint:syscalls:sys_enter_openat*
{
// TODO: pass partial string name as argument instead of fucking grepping
//  $filename = str(args->filename);
//  $string = str($1);
//  if ( strncmp($filename, $string, 3) ) {
    @filename[tid] = args->filename;
    @flags[tid] = args->flags;
    @start[tid] = nsecs;
    @dfd[tid] = args->dfd;
//  }
}

tracepoint:syscalls:sys_exit_openat* /@filename[tid]/
{
	$ret = args->ret;
	$fd = $ret >= 0 ? $ret : -1;
	$errno = $ret >= 0 ? 0 : - $ret;
  $usecs = (nsecs - @start[tid]) / 1000;
// AT_FDCWD = -100 dfd, i.e. in current working directory of the calling process
//	printf("%d usec %s:%d:%d fd:%d dfd:%d err:%d flags:%d %s %s\n",
//    $usecs, comm, pid, tid, $fd, @dfd[tid], $errno, @flags[tid], str(@filename[tid]), strftime("%H:%M:%S:%f",nsecs));
// just a different format, and actually prints the latency

	printf("%s:%d:%d %s fd:%d dfd:%d err:%d flags:%d %s\n",
         comm, pid, tid, str(@filename[tid]), $fd, @dfd[tid], $errno, @flags[tid], strftime("%H:%M:%S:%f",nsecs));
  delete(@filename[tid]);
  delete(@start[tid]);
  delete(@flags[tid]);
  delete(@dfd[tid]);
}