[libvirt] [PATCH 1/3] virsh: add option aliases

[Osier Yang]

On 03/07/2012 03:33 PM, Osier Yang wrote:
> On 03/03/2012 09:02 AM, Eric Blake wrote:
>> In the past, we have created some virsh options with less-than-stellar
>> names. For back-compat reasons, those names must continue to parse,
>> but we don't want to document them in help output. This introduces
>> a new option type, an alias, which points to a canonical option name
>> later in the option list.
>>
>> I'm actually quite impressed that our code has already been factored
>> to do all option parsing through common entry points, such that I
>> got this added in relatively few lines of code!
>>
>> * tools/virsh.c (VSH_OT_ALIAS): New option type.
>> (opts_echo): Hook up an alias, for easy testing.
>> (vshCmddefOptParse, vshCmddefHelp, vshCmddefGetOption): Allow for
>> aliases.
>> * tests/virshtest.c (mymain): Test new feature.
>> ---
>> tests/virshtest.c | 6 ++++++
>> tools/virsh.c | 28 ++++++++++++++++++++++++++--
>> 2 files changed, 32 insertions(+), 2 deletions(-)
>>
>> diff --git a/tests/virshtest.c b/tests/virshtest.c
>> index 6474c19..87b1336 100644
>> --- a/tests/virshtest.c
>> +++ b/tests/virshtest.c
>> @@ -386,6 +386,12 @@ mymain(void)
>> DO_TEST(30, "--shell a\n",
>> "echo \t '-'\"-\" \t --shell \t a");
>>
>> + /* Tests of alias handling. */
>> + DO_TEST(31, "hello\n", "echo", "--string", "hello");
>> + DO_TEST(32, "hello\n", "echo --string hello");
>> + DO_TEST(33, "hello\n", "echo", "--str", "hello");
>> + DO_TEST(34, "hello\n", "echo --str hello");
>> +
>> # undef DO_TEST
>>
>> VIR_FREE(custom_uri);
>> diff --git a/tools/virsh.c b/tools/virsh.c
>> index aef050f..77cf4ac 100644
>> --- a/tools/virsh.c
>> +++ b/tools/virsh.c
>> @@ -138,7 +138,8 @@ typedef enum {
>> VSH_OT_STRING, /* optional string option */
>> VSH_OT_INT, /* optional or mandatory int option */
>> VSH_OT_DATA, /* string data (as non-option) */
>> - VSH_OT_ARGV /* remaining arguments */
>> + VSH_OT_ARGV, /* remaining arguments */
>> + VSH_OT_ALIAS, /* alternate spelling for a later argument */
>> } vshCmdOptType;
>>
>> /*
>> @@ -190,7 +191,8 @@ typedef struct {
>> const char *name; /* the name of option, or NULL for list end */
>> vshCmdOptType type; /* option type */
>> unsigned int flags; /* flags */
>> - const char *help; /* non-NULL help string */
>> + const char *help; /* non-NULL help string; or for VSH_OT_ALIAS
>> + * the name of a later public option */
>> } vshCmdOptDef;
>>
>> /*
>> @@ -15209,6 +15211,7 @@ static const vshCmdInfo info_echo[] = {
>> static const vshCmdOptDef opts_echo[] = {
>> {"shell", VSH_OT_BOOL, 0, N_("escape for shell use")},
>> {"xml", VSH_OT_BOOL, 0, N_("escape for XML use")},
>> + {"str", VSH_OT_ALIAS, 0, "string"},
>> {"string", VSH_OT_ARGV, 0, N_("arguments to echo")},
>> {NULL, 0, 0, NULL}
>> };
>> @@ -17256,6 +17259,18 @@ vshCmddefOptParse(const vshCmdDef *cmd,
>> uint32_t *opts_need_arg,
>> return -1; /* bool options can't be mandatory */
>> continue;
>> }
>> + if (opt->type == VSH_OT_ALIAS) {
>> + int j;
>> + if (opt->flags || !opt->help)
>> + return -1; /* alias options are tracked by the original name */
>> + for (j = i + 1; cmd->opts[j].name; j++) {
>> + if (STREQ(opt->help, cmd->opts[j].name))
>> + break;
>> + }
>> + if (!cmd->opts[j].name)
>> + return -1; /* alias option must map to a later option name */
>> + continue;
>> + }
>> if (opt->flags& VSH_OFLAG_REQ_OPT) {
>> if (opt->flags& VSH_OFLAG_REQ)
>> *opts_required |= 1<< i;
>> @@ -17287,6 +17302,10 @@ vshCmddefGetOption(vshControl *ctl, const
>> vshCmdDef *cmd, const char *name,
>> const vshCmdOptDef *opt =&cmd->opts[i];
>>
>> if (STREQ(opt->name, name)) {
>> + if (opt->type == VSH_OT_ALIAS) {
>> + name = opt->help;
>> + continue;
>> + }
>> if ((*opts_seen& (1<< i))&& opt->type != VSH_OT_ARGV) {
>> vshError(ctl, _("option --%s already seen"), name);
>> return NULL;
>> @@ -17465,6 +17484,9 @@ vshCmddefHelp(vshControl *ctl, const char
>> *cmdname)
>> : _("[<%s>]...");
>> }
>> break;
>> + case VSH_OT_ALIAS:
>> + /* aliases are intentionally undocumented */
>> + continue;
>> default:
>> assert(0);
>> }
>> @@ -17506,6 +17528,8 @@ vshCmddefHelp(vshControl *ctl, const char
>> *cmdname)
>> shortopt ? _("[--%s]<string>") : _("<%s>"),
>> opt->name);
>> break;
>> + case VSH_OT_ALIAS:
>> + continue;
>> default:
>> assert(0);
>> }
>
> Ah, I could recall we talked about this half year before, for
> creating alias ("--config") for the options "--persistent" of
> commands like "attach-device", then I forgot it to do it.
>

I created a patch which can be served as 4/4 of these series,
for the "--persistent" changes.

Osier