4.1.2.9 trace

void trace(expression)

The trace action is the most basic action. This action takes a D expression as its argument and then traces the result to the directed buffer. 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 on a buffer, the output format depends on the data type. If the dtrace command determines that the data is like an ASCII string, it prints it as text and terminates the output with a null character (0). When dtrace decides that the data is most likely binary, it prints it in 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<.<........

You can force the trace action to always use the binary format by specifying the rawbytes option.