1 #include "cache.h"
2 #include <subcmd/help.h>
3 #include "../builtin.h"
4 #include "levenshtein.h"
5 
6 static int autocorrect;
7 static struct cmdnames aliases;
8 
9 static int perf_unknown_cmd_config(const char *var, const char *value, void *cb)
10 {
11 	if (!strcmp(var, "help.autocorrect"))
12 		autocorrect = perf_config_int(var,value);
13 	/* Also use aliases for command lookup */
14 	if (!prefixcmp(var, "alias."))
15 		add_cmdname(&aliases, var + 6, strlen(var + 6));
16 
17 	return perf_default_config(var, value, cb);
18 }
19 
20 static int levenshtein_compare(const void *p1, const void *p2)
21 {
22 	const struct cmdname *const *c1 = p1, *const *c2 = p2;
23 	const char *s1 = (*c1)->name, *s2 = (*c2)->name;
24 	int l1 = (*c1)->len;
25 	int l2 = (*c2)->len;
26 	return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
27 }
28 
29 static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
30 {
31 	unsigned int i;
32 
33 	ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
34 
35 	for (i = 0; i < old->cnt; i++)
36 		cmds->names[cmds->cnt++] = old->names[i];
37 	zfree(&old->names);
38 	old->cnt = 0;
39 }
40 
41 const char *help_unknown_cmd(const char *cmd)
42 {
43 	unsigned int i, n = 0, best_similarity = 0;
44 	struct cmdnames main_cmds, other_cmds;
45 
46 	memset(&main_cmds, 0, sizeof(main_cmds));
47 	memset(&other_cmds, 0, sizeof(main_cmds));
48 	memset(&aliases, 0, sizeof(aliases));
49 
50 	perf_config(perf_unknown_cmd_config, NULL);
51 
52 	load_command_list("perf-", &main_cmds, &other_cmds);
53 
54 	add_cmd_list(&main_cmds, &aliases);
55 	add_cmd_list(&main_cmds, &other_cmds);
56 	qsort(main_cmds.names, main_cmds.cnt,
57 	      sizeof(main_cmds.names), cmdname_compare);
58 	uniq(&main_cmds);
59 
60 	if (main_cmds.cnt) {
61 		/* This reuses cmdname->len for similarity index */
62 		for (i = 0; i < main_cmds.cnt; ++i)
63 			main_cmds.names[i]->len =
64 				levenshtein(cmd, main_cmds.names[i]->name, 0, 2, 1, 4);
65 
66 		qsort(main_cmds.names, main_cmds.cnt,
67 		      sizeof(*main_cmds.names), levenshtein_compare);
68 
69 		best_similarity = main_cmds.names[0]->len;
70 		n = 1;
71 		while (n < main_cmds.cnt && best_similarity == main_cmds.names[n]->len)
72 			++n;
73 	}
74 
75 	if (autocorrect && n == 1) {
76 		const char *assumed = main_cmds.names[0]->name;
77 
78 		main_cmds.names[0] = NULL;
79 		clean_cmdnames(&main_cmds);
80 		fprintf(stderr, "WARNING: You called a perf program named '%s', "
81 			"which does not exist.\n"
82 			"Continuing under the assumption that you meant '%s'\n",
83 			cmd, assumed);
84 		if (autocorrect > 0) {
85 			fprintf(stderr, "in %0.1f seconds automatically...\n",
86 				(float)autocorrect/10.0);
87 			poll(NULL, 0, autocorrect * 100);
88 		}
89 		return assumed;
90 	}
91 
92 	fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
93 
94 	if (main_cmds.cnt && best_similarity < 6) {
95 		fprintf(stderr, "\nDid you mean %s?\n",
96 			n < 2 ? "this": "one of these");
97 
98 		for (i = 0; i < n; i++)
99 			fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
100 	}
101 
102 	exit(1);
103 }
104