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. --- tools/virsh.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/tools/virsh.c b/tools/virsh.c index 64e2e18..324f789 100644 --- a/tools/virsh.c +++ b/tools/virsh.c @@ -1189,12 +1189,18 @@ vshCmddefOptParse(const vshCmdDef *cmd, uint32_t *opts_need_arg, return 0; } +vshCmdOptDef helpopt = {"help", VSH_OT_BOOL, 0, + N_("print help for this function")}; 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; + + vshCommandOptFree(first); + first = vshMalloc(ctl, sizeof(vshCmdOpt)); + first->def = &(opts_help[0]); + first->data = vshStrdup(ctl, cmd->name); + first->next = NULL; + + cmd = vshCmddefSearch("help"); + opts_required = 0; + opts_seen = 0; + break; + } c->opts = first; c->def = cmd; -- 1.7.11.2

On Mon, Aug 13, 2012 at 9:28 AM, Cole Robinson <crobinso(a)redhat.com&gt; wrote: > Similar to the previous patch, prepending 'help' to a partial > command string doesn't cut us any slack. > > $ virsh help pool-define-as --name foo --type dir > error: command 'help' doesn't support option --name > > This patch adds a few hacks to make 'help' ignore everything after the > first data bit, so the above command shows help output for pool-define-as. > --- > tools/virsh.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/tools/virsh.c b/tools/virsh.c > index 324f789..ab8d6dc 100644 > --- a/tools/virsh.c > +++ b/tools/virsh.c > @@ -1219,8 +1219,10 @@ vshCmddefGetOption(vshControl *ctl, const vshCmdDef *cmd, const char *name, > } > } > > - vshError(ctl, _("command '%s' doesn't support option --%s"), > - cmd->name, name); > + if (STRNEQ(cmd->name, "help")) { > + vshError(ctl, _("command '%s' doesn't support option --%s"), > + cmd->name, name); > + } > return NULL; > } > > @@ -1987,9 +1989,12 @@ vshCommandParse(vshControl *ctl, vshCommandParser *parser) > *optstr = '\0'; /* convert the '=' to '\0' */ > optstr = vshStrdup(ctl, optstr + 1); > } > + /* Special case 'help' to ignore all spurious options */ > if (!(opt = vshCmddefGetOption(ctl, cmd, tkdata + 2, > &opts_seen, &opt_index))) { > VIR_FREE(optstr); > + if (STREQ(cmd->name, "help")) > + continue; > goto syntaxError; > } > VIR_FREE(tkdata); > @@ -2027,8 +2032,10 @@ vshCommandParse(vshControl *ctl, vshCommandParser *parser) > continue; > } else { > get_data: > + /* Special case 'help' to ignore spurious data */ > if (!(opt = vshCmddefGetData(cmd, &opts_need_arg, > - &opts_seen))) { > + &opts_seen)) && > + STRNEQ(cmd->name, "help")) { > vshError(ctl, _("unexpected data '%s'"), tkdata); > goto syntaxError; > } > -- > 1.7.11.2 > Worked for me when I tested it with the previous patches so ACK.