trace
Action
void trace(expression)
The most basic action is the trace
action, which takes a D expression as its argument and traces the result to the directed buffer. You can force trace
to use binary format for ASCII text by using the rawbytes
option.
Example 4-1 Tracing Actions
The following statements are examples of trace
actions:
trace(execname); trace(curlwpsinfo->pr_pri); trace(timestamp / 1000); trace(`lbolt); trace("somehow managed to get here");
If the trace
action is used to record a buffer, the output format depends on the data that is collected. If dtrace
decides that the data looks like an ASCII string, it prints text and the output is terminated by the first null byte. However, if dtrace
decides that the data is in a binary form, it prints the output in a hexadecimal format. For example:
0 342 write:entry 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef 0: c0 de 09 c2 4a e8 27 54 dc f8 9f f1 9a 20 4b d1 ....J.'T..... K. 10: 9c 7a 7a 85 1b 03 0a fb 3a 81 8a 1b 25 35 b3 9a .zz.....:...%5.. 20: f1 7d e6 2b 66 6d 1c 11 f8 eb 40 7f 65 9a 25 f8 .}.+fm....@.e.%. 30: c8 68 87 b2 6f 48 a2 a5 f3 a2 1f 46 ab 3d f9 d2 .h..oH.....F.=.. 40: 3d b8 4c c0 41 3c f7 3c cd 18 ad 0d 0d d3 1a 90 =.L.A<.<........