[PATCH 7/9] vsh: Rework how option to complete is found
Michal Privoznik
mprivozn at redhat.com
Tue Jan 26 13:27:11 UTC 2021
The way that auto completion works currently is that user's input
is parsed, and then we try to find the first --option (in the
parsed structure) that has the same value as user's input around
where <TAB> was pressed. For instance, for the following input:
virsh # command --arg1 hello --arg2 world<TAB>
we will see "world" as text that user is trying to autocomplete
(this is affected by rl_basic_word_break_characters which
readline uses internally to break user's input into individual
words) and find that it is --arg2 that user is trying to
autocomplete. So far so good, for this naive approach. But
consider the following example:
virsh # command --arg1 world --arg2 world<TAB>
Here, both arguments have the same value and because we see
"world" as text that user is trying to autocomplete we would
think that it is --arg1 that user wants to autocomplete. This is
obviously wrong.
Fortunately, readline stores the current position of cursor (into
rl_point) and we can use that when parsing user's input: whenever
we reach a position that matches the cursor then we know that
that is the place where <TAB> was pressed and hence that is the
--option that user wants to autocomplete. Readline stores the
cursor position as offset (numbered from 1) from the beginning of
user's input. We store this input into @parser->pos initially,
but then advance it as we tokenize it. Therefore, what we need is
to store the original position too.
Thanks to Martin who helped me with this.
Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
tools/virsh.c | 4 ++--
tools/virt-admin.c | 4 ++--
tools/vsh.c | 58 ++++++++++++++++++++++++++++++++--------------
tools/vsh.h | 5 +++-
4 files changed, 49 insertions(+), 22 deletions(-)
diff --git a/tools/virsh.c b/tools/virsh.c
index a6bfbbbb87..732655a894 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -777,7 +777,7 @@ virshParseArgv(vshControl *ctl, int argc, char **argv)
ctl->imode = false;
if (argc - optind == 1) {
vshDebug(ctl, VSH_ERR_INFO, "commands: \"%s\"\n", argv[optind]);
- return vshCommandStringParse(ctl, argv[optind], NULL);
+ return vshCommandStringParse(ctl, argv[optind], NULL, 0);
} else {
return vshCommandArgvParse(ctl, argc - optind, argv + optind);
}
@@ -915,7 +915,7 @@ main(int argc, char **argv)
if (*ctl->cmdstr) {
vshReadlineHistoryAdd(ctl->cmdstr);
- if (vshCommandStringParse(ctl, ctl->cmdstr, NULL))
+ if (vshCommandStringParse(ctl, ctl->cmdstr, NULL, 0))
vshCommandRun(ctl, ctl->cmd);
}
VIR_FREE(ctl->cmdstr);
diff --git a/tools/virt-admin.c b/tools/virt-admin.c
index 72084a78e9..1108a07896 100644
--- a/tools/virt-admin.c
+++ b/tools/virt-admin.c
@@ -1364,7 +1364,7 @@ vshAdmParseArgv(vshControl *ctl, int argc, char **argv)
ctl->imode = false;
if (argc - optind == 1) {
vshDebug(ctl, VSH_ERR_INFO, "commands: \"%s\"\n", argv[optind]);
- return vshCommandStringParse(ctl, argv[optind], NULL);
+ return vshCommandStringParse(ctl, argv[optind], NULL, 0);
} else {
return vshCommandArgvParse(ctl, argc - optind, argv + optind);
}
@@ -1594,7 +1594,7 @@ main(int argc, char **argv)
if (*ctl->cmdstr) {
vshReadlineHistoryAdd(ctl->cmdstr);
- if (vshCommandStringParse(ctl, ctl->cmdstr, NULL))
+ if (vshCommandStringParse(ctl, ctl->cmdstr, NULL, 0))
vshCommandRun(ctl, ctl->cmd);
}
VIR_FREE(ctl->cmdstr);
diff --git a/tools/vsh.c b/tools/vsh.c
index 27c201389d..e5c6cebebb 100644
--- a/tools/vsh.c
+++ b/tools/vsh.c
@@ -1318,6 +1318,8 @@ struct _vshCommandParser {
char **, bool);
/* vshCommandStringGetArg() */
char *pos;
+ const char *originalLine;
+ size_t point;
/* vshCommandArgvGetArg() */
char **arg_pos;
char **arg_end;
@@ -1426,6 +1428,10 @@ vshCommandParse(vshControl *ctl, vshCommandParser *parser, vshCmd **partial)
arg->data = tkdata;
tkdata = NULL;
arg->next = NULL;
+
+ if (parser->pos - parser->originalLine == parser->point - 1)
+ arg->completeThis = true;
+
if (!first)
first = arg;
if (last)
@@ -1477,6 +1483,9 @@ vshCommandParse(vshControl *ctl, vshCommandParser *parser, vshCmd **partial)
arg->next = NULL;
tkdata = NULL;
+ if (parser->pos - parser->originalLine == parser->point)
+ arg->completeThis = true;
+
if (!first)
first = arg;
if (last)
@@ -1588,7 +1597,7 @@ vshCommandArgvGetArg(vshControl *ctl G_GNUC_UNUSED,
bool
vshCommandArgvParse(vshControl *ctl, int nargs, char **argv)
{
- vshCommandParser parser;
+ vshCommandParser parser = { 0 };
if (nargs <= 0)
return false;
@@ -1675,15 +1684,38 @@ vshCommandStringGetArg(vshControl *ctl, vshCommandParser *parser, char **res,
return VSH_TK_ARG;
}
+
+/**
+ * vshCommandStringParse:
+ * @ctl virsh control structure
+ * @cmdstr: string to parse
+ * @partial: store partially parsed command here
+ * @point: position of cursor (rl_point)
+ *
+ * Parse given string @cmdstr as a command and store it under
+ * @ctl->cmd. For readline completion, if @partial is not NULL on
+ * the input then errors in parsing are ignored (because user is
+ * still in progress of writing the command string) and partially
+ * parsed command is stored at *@partial (caller has to free it
+ * afterwards). Among with @partial, caller must set @point which
+ * is the position of cursor in @cmdstr (offset, numbered from 1).
+ * Parser will then set @completeThis attribute to true for the
+ * vshCmdOpt that appeared under the cursor.
+ */
bool
-vshCommandStringParse(vshControl *ctl, char *cmdstr, vshCmd **partial)
+vshCommandStringParse(vshControl *ctl,
+ char *cmdstr,
+ vshCmd **partial,
+ size_t point)
{
- vshCommandParser parser;
+ vshCommandParser parser = { 0 };
if (cmdstr == NULL || *cmdstr == '\0')
return false;
parser.pos = cmdstr;
+ parser.originalLine = cmdstr;
+ parser.point = point;
parser.getNextArg = vshCommandStringGetArg;
return vshCommandParse(ctl, &parser, partial);
}
@@ -2634,28 +2666,20 @@ vshReadlineOptionsGenerator(const char *text,
static const vshCmdOptDef *
-vshReadlineCommandFindOpt(const vshCmd *partial,
- const char *text)
+vshReadlineCommandFindOpt(const vshCmd *partial)
{
const vshCmd *tmp = partial;
- while (tmp && tmp->next) {
- if (tmp->def == tmp->next->def &&
- !tmp->next->opts)
- break;
- tmp = tmp->next;
- }
-
- if (tmp && tmp->opts) {
+ while (tmp) {
const vshCmdOpt *opt = tmp->opts;
while (opt) {
- if (STREQ_NULLABLE(opt->data, text) ||
- STREQ_NULLABLE(opt->data, " "))
+ if (opt->completeThis)
return opt->def;
opt = opt->next;
}
+ tmp = tmp->next;
}
return NULL;
@@ -2717,7 +2741,7 @@ vshReadlineParse(const char *text, int state)
*(line + rl_point) = '\0';
- vshCommandStringParse(NULL, line, &partial);
+ vshCommandStringParse(NULL, line, &partial, rl_point);
if (partial) {
cmd = partial->def;
@@ -2735,7 +2759,7 @@ vshReadlineParse(const char *text, int state)
cmd = NULL;
}
- opt = vshReadlineCommandFindOpt(partial, text);
+ opt = vshReadlineCommandFindOpt(partial);
if (!cmd) {
list = vshReadlineCommandGenerator(text);
diff --git a/tools/vsh.h b/tools/vsh.h
index 0c5584891d..39f70913fe 100644
--- a/tools/vsh.h
+++ b/tools/vsh.h
@@ -152,6 +152,8 @@ struct _vshCmdOptDef {
struct _vshCmdOpt {
const vshCmdOptDef *def; /* non-NULL pointer to option definition */
char *data; /* allocated data, or NULL for bool option */
+ bool completeThis; /* true if this is the option user's wishing to
+ autocomplete */
vshCmdOpt *next;
};
@@ -292,7 +294,8 @@ int vshBlockJobOptionBandwidth(vshControl *ctl,
unsigned long *bandwidth);
bool vshCommandOptBool(const vshCmd *cmd, const char *name);
bool vshCommandRun(vshControl *ctl, const vshCmd *cmd);
-bool vshCommandStringParse(vshControl *ctl, char *cmdstr, vshCmd **partial);
+bool vshCommandStringParse(vshControl *ctl, char *cmdstr,
+ vshCmd **partial, size_t point);
const vshCmdOpt *vshCommandOptArgv(vshControl *ctl, const vshCmd *cmd,
const vshCmdOpt *opt);
--
2.26.2
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