<para>Type of event to be triggered. Possible actions are <literal>add</literal>,
<literal>remove</literal>, <literal>change</literal>, <literal>move</literal>,
<literal>online</literal>, <literal>offline</literal>, <literal>bind</literal>,
- and <literal>unbind</literal>. The default value is <literal>change</literal>.</para>
+ and <literal>unbind</literal>. Also, the special value <literal>help</literal> can be used
+ to list the possible actions. The default value is <literal>change</literal>.
+ </para>
</listitem>
</varlistentry>
<varlistentry>
<variablelist>
<varlistentry>
<term><option>-a</option></term>
- <term><option>--action=<replaceable>string</replaceable></option></term>
+ <term><option>--action=<replaceable>ACTION</replaceable></option></term>
<listitem>
- <para>The action string.</para>
+ <para>The action string. The special value <literal>help</literal> may be used to list
+ known values.</para>
</listitem>
</varlistentry>
<varlistentry>
"Test an event run.\n\n"
" -h --help Show this help\n"
" -V --version Show package version\n"
- " -a --action=ACTION Set action string\n"
+ " -a --action=ACTION|help Set action string\n"
" -N --resolve-names=early|late|never When to resolve names\n"
, program_invocation_short_name);
case 'a': {
DeviceAction a;
+ if (streq(optarg, "help")) {
+ dump_device_action_table();
+ return 0;
+ }
+
a = device_action_from_string(optarg);
if (a < 0)
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
" -t --type= Type of events to trigger\n"
" devices sysfs devices (default)\n"
" subsystems sysfs subsystems and drivers\n"
- " -c --action=ACTION Event action value, default is \"change\"\n"
+ " -c --action=ACTION|help Event action value, default is \"change\"\n"
" -s --subsystem-match=SUBSYSTEM Trigger devices from a matching subsystem\n"
" -S --subsystem-nomatch=SUBSYSTEM Exclude devices from a matching subsystem\n"
" -a --attr-match=FILE[=VALUE] Trigger devices with a matching attribute\n"
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown type --type=%s", optarg);
break;
case 'c':
+ if (streq(optarg, "help")) {
+ dump_device_action_table();
+ return 0;
+ }
if (device_action_from_string(optarg) < 0)
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown action '%s'", optarg);