fprintf(ofp, " TRACE_DEBUG = 14\n");
fprintf(ofp, " (shortcuts such as \"system\" are allowed)\n");
fprintf(ofp, " --filter \'expression\'\n");
- fprintf(ofp, " Filter expression on event fields,\n");
- fprintf(ofp, " event recording depends on evaluation.\n");
+ fprintf(ofp, " Filter expression on event fields and context.\n");
+ fprintf(ofp, " Event recording depends on evaluation.\n");
fprintf(ofp, " Only specify on first activation of\n");
fprintf(ofp, " a given event within a session.\n");
fprintf(ofp, " Filter only allowed when enabling\n");
fprintf(ofp, " 'seqfield1 == \"te*\"'\n");
fprintf(ofp, " In string literals, the escape character is '\\'.\n");
fprintf(ofp, " Use '\\*' for the '*' character, and '\\\\' for\n");
- fprintf(ofp, " the '\\' character.\n");
+ fprintf(ofp, " the '\\' character. Wildcard match any sequence of,\n");
+ fprintf(ofp, " characters including an empty sub-string (match 0 or\n");
+ fprintf(ofp, " more characters).\n");
+ fprintf(ofp, "\n");
+ fprintf(ofp, " Context information can be used for filtering. The\n");
+ fprintf(ofp, " examples below show usage of context filtering on\n");
+ fprintf(ofp, " process name (with a wildcard), process ID range, and\n");
+ fprintf(ofp, " unique thread ID for filtering. The process and\n");
+ fprintf(ofp, " thread ID of running applications can be found under\n");
+ fprintf(ofp, " columns \"PID\" and \"LWP\" of the \"ps -eLf\" command.\n");
+ fprintf(ofp, "\n");
+ fprintf(ofp, " '$ctx.procname == \"demo*\"'\n");
+ fprintf(ofp, " '$ctx.vpid >= 4433 && $ctx.vpid < 4455'\n");
+ fprintf(ofp, " '$ctx.vtid == 1234'\n");
fprintf(ofp, "\n");
}