1// SPDX-License-Identifier: GPL-2.0
2#include "cache.h"
3#include "config.h"
4#include <poll.h>
5#include <stdio.h>
6#include <stdlib.h>
7#include <subcmd/help.h>
8#include "../builtin.h"
9#include "levenshtein.h"
10#include <linux/zalloc.h>
11
12static int autocorrect;
13
14static int perf_unknown_cmd_config(const char *var, const char *value,
15 void *cb __maybe_unused)
16{
17 if (!strcmp(var, "help.autocorrect"))
18 return perf_config_int(dest: &autocorrect, var,value);
19
20 return 0;
21}
22
23static int levenshtein_compare(const void *p1, const void *p2)
24{
25 const struct cmdname *const *c1 = p1, *const *c2 = p2;
26 const char *s1 = (*c1)->name, *s2 = (*c2)->name;
27 int l1 = (*c1)->len;
28 int l2 = (*c2)->len;
29 return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
30}
31
32static int add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
33{
34 unsigned int i, nr = cmds->cnt + old->cnt;
35 void *tmp;
36
37 if (nr > cmds->alloc) {
38 /* Choose bigger one to alloc */
39 if (alloc_nr(cmds->alloc) < nr)
40 cmds->alloc = nr;
41 else
42 cmds->alloc = alloc_nr(cmds->alloc);
43 tmp = realloc(cmds->names, cmds->alloc * sizeof(*cmds->names));
44 if (!tmp)
45 return -1;
46 cmds->names = tmp;
47 }
48 for (i = 0; i < old->cnt; i++)
49 cmds->names[cmds->cnt++] = old->names[i];
50 zfree(&old->names);
51 old->cnt = 0;
52 return 0;
53}
54
55const char *help_unknown_cmd(const char *cmd, struct cmdnames *main_cmds)
56{
57 unsigned int i, n = 0, best_similarity = 0;
58 struct cmdnames other_cmds;
59
60 memset(&other_cmds, 0, sizeof(other_cmds));
61
62 perf_config(fn: perf_unknown_cmd_config, NULL);
63
64 load_command_list("perf-", main_cmds, &other_cmds);
65
66 if (add_cmd_list(cmds: main_cmds, old: &other_cmds) < 0) {
67 fprintf(stderr, "ERROR: Failed to allocate command list for unknown command.\n");
68 goto end;
69 }
70 qsort(main_cmds->names, main_cmds->cnt,
71 sizeof(main_cmds->names), cmdname_compare);
72 uniq(main_cmds);
73
74 if (main_cmds->cnt) {
75 /* This reuses cmdname->len for similarity index */
76 for (i = 0; i < main_cmds->cnt; ++i) {
77 main_cmds->names[i]->len =
78 levenshtein(string1: cmd, string2: main_cmds->names[i]->name,
79 /*swap_penalty=*/0,
80 /*substition_penality=*/substition_penalty: 2,
81 /*insertion_penality=*/insertion_penalty: 1,
82 /*deletion_penalty=*/1);
83 }
84 qsort(main_cmds->names, main_cmds->cnt,
85 sizeof(*main_cmds->names), levenshtein_compare);
86
87 best_similarity = main_cmds->names[0]->len;
88 n = 1;
89 while (n < main_cmds->cnt && best_similarity == main_cmds->names[n]->len)
90 ++n;
91 }
92
93 if (autocorrect && n == 1) {
94 const char *assumed = main_cmds->names[0]->name;
95
96 main_cmds->names[0] = NULL;
97 clean_cmdnames(&other_cmds);
98 fprintf(stderr, "WARNING: You called a perf program named '%s', "
99 "which does not exist.\n"
100 "Continuing under the assumption that you meant '%s'\n",
101 cmd, assumed);
102 if (autocorrect > 0) {
103 fprintf(stderr, "in %0.1f seconds automatically...\n",
104 (float)autocorrect/10.0);
105 poll(NULL, 0, autocorrect * 100);
106 }
107 return assumed;
108 }
109
110 fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
111
112 if (main_cmds->cnt && best_similarity < 6) {
113 fprintf(stderr, "\nDid you mean %s?\n",
114 n < 2 ? "this": "one of these");
115
116 for (i = 0; i < n; i++)
117 fprintf(stderr, "\t%s\n", main_cmds->names[i]->name);
118 }
119end:
120 clean_cmdnames(&other_cmds);
121 return NULL;
122}
123

source code of linux/tools/perf/util/help-unknown-cmd.c