Improve friendliness of --cmdhelp
If no match is found, print the closest. Quite handy when
you can't quite remember the exact option name.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/parse.c b/parse.c
index ee7ddf2..7956575 100644
--- a/parse.c
+++ b/parse.c
@@ -437,7 +437,46 @@
return 1;
}
-int show_cmd_help(struct fio_option *options, const char *name)
+/*
+ * Option match, levenshtein distance. Handy for not quite remembering what
+ * the option name is.
+ */
+static int string_distance(const char *s1, const char *s2)
+{
+ unsigned int s1_len = strlen(s1);
+ unsigned int s2_len = strlen(s2);
+ unsigned int *p, *q, *r;
+ unsigned int i, j;
+
+ p = malloc(sizeof(unsigned int) * (s2_len + 1));
+ q = malloc(sizeof(unsigned int) * (s2_len + 1));
+
+ p[0] = 0;
+ for (i = 1; i <= s2_len; i++)
+ p[i] = p[i - 1] + 1;
+
+ for (i = 1; i <= s1_len; i++) {
+ q[0] = p[0] + 1;
+ for (j = 1; j <= s2_len; j++) {
+ unsigned int sub = p[j - 1];
+
+ if (s1[i - 1] != s2[j - 1])
+ sub++;
+
+ q[j] = min(p[j] + 1, min(q[j - 1] + 1, sub));
+ }
+ r = p;
+ p = q;
+ q = r;
+ }
+
+ i = p[s2_len];
+ free(p);
+ free(q);
+ return i;
+}
+
+static void show_option_help(struct fio_option *o)
{
const char *typehelp[] = {
"string (opt=bla)",
@@ -450,18 +489,41 @@
"boolean value (opt=1)",
"no argument (opt)",
};
- struct fio_option *o;
+
+ printf("%20s: %s\n", "type", typehelp[o->type]);
+ printf("%20s: %s\n", "default", o->def ? o->def : "no default");
+ show_option_range(o);
+ show_option_values(o);
+}
+
+int show_cmd_help(struct fio_option *options, const char *name)
+{
+ struct fio_option *o, *closest;
+ unsigned int best_dist;
int found = 0;
int show_all = 0;
if (!name || !strcmp(name, "all"))
show_all = 1;
+ closest = NULL;
+ best_dist = -1;
for (o = &options[0]; o->name; o++) {
int match = 0;
- if (name && !strcmp(name, o->name))
- match = 1;
+ if (name) {
+ if (!strcmp(name, o->name))
+ match = 1;
+ else {
+ unsigned int dist;
+
+ dist = string_distance(name, o->name);
+ if (dist < best_dist) {
+ best_dist = dist;
+ closest = o;
+ }
+ }
+ }
if (show_all || match) {
found = 1;
@@ -473,16 +535,20 @@
if (!match)
continue;
- printf("%20s: %s\n", "type", typehelp[o->type]);
- printf("%20s: %s\n", "default", o->def ? o->def : "no default");
- show_option_range(o);
- show_option_values(o);
+ show_option_help(o);
}
if (found)
return 0;
- printf("No such command: %s\n", name);
+ printf("No such command: %s", name);
+ if (closest) {
+ printf(" - showing closest match\n");
+ printf("%20s: %s\n", closest->name, closest->help);
+ show_option_help(closest);
+ } else
+ printf("\n");
+
return 1;
}
diff --git a/parse.h b/parse.h
index 214e56b..1a71864 100644
--- a/parse.h
+++ b/parse.h
@@ -67,4 +67,11 @@
#define td_var(start, offset) ((void *) start + (offset))
+#ifndef min
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#endif
+#ifndef max
+#define max(a, b) ((a) > (b) ? (a) : (b))
+#endif
+
#endif