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@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org