On 08/13/2012 08:28 AM, Cole Robinson wrote:
Often times I find myself halfway through typing a long command when
I want to see 'help' output. I instinctively append '--help' to the
command I'm typing, only to get an error:
$ virsh vol-create-as foo --help
error: command 'vol-create-as' doesn't support option --help
This patch makes --help work in a pretty hacky way. One missing piece
here is that --help isn't listed as an option in the actual 'help
<cmd>'
output, but maybe this can be a starting point for someone.
Love this hack - I too have missed having it.
---
tools/virsh.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
+vshCmdOptDef helpopt = {"help", VSH_OT_BOOL, 0,
+ N_("print help for this function")};
Mark this static.
static const vshCmdOptDef *
vshCmddefGetOption(vshControl *ctl, const vshCmdDef *cmd, const char *name,
uint32_t *opts_seen, int *opt_index)
{
int i;
+ if (STREQ(name, helpopt.name)) {
+ return &helpopt;
+ }
+
for (i = 0; cmd->opts && cmd->opts[i].name; i++) {
const vshCmdOptDef *opt = &cmd->opts[i];
@@ -2053,6 +2059,25 @@ get_data:
/* command parsed -- allocate new struct for the command */
if (cmd) {
vshCmd *c = vshMalloc(ctl, sizeof(vshCmd));
+ vshCmdOpt *tmpopt = first;
+
+ /* if we encountered --help, replace parsed command with
+ * 'help <cmdname>' */
+ for (tmpopt = first; tmpopt; tmpopt = tmpopt->next) {
+ if (STRNEQ(tmpopt->def->name, "help"))
+ continue;
I tested corner cases like:
virsh echo --help # full help output
virsh echo -- --help # literal '--help'
virsh echo --string --help # literal '--help'
and it appears to match my expectations.
ACK.
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library
http://libvirt.org