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)
56{
57 unsigned int i, n = 0, best_similarity = 0;
58 struct cmdnames main_cmds, other_cmds;
59
60 memset(&main_cmds, 0, sizeof(main_cmds));
61 memset(&other_cmds, 0, sizeof(main_cmds));
62
63 perf_config(fn: perf_unknown_cmd_config, NULL);
64
65 load_command_list("perf-", &main_cmds, &other_cmds);
66
67 if (add_cmd_list(cmds: &main_cmds, old: &other_cmds) < 0) {
68 fprintf(stderr, "ERROR: Failed to allocate command list for unknown command.\n");
69 goto end;
70 }
71 qsort(main_cmds.names, main_cmds.cnt,
72 sizeof(main_cmds.names), cmdname_compare);
73 uniq(&main_cmds);
74
75 if (main_cmds.cnt) {
76 /* This reuses cmdname->len for similarity index */
77 for (i = 0; i < main_cmds.cnt; ++i)
78 main_cmds.names[i]->len =
79 levenshtein(string1: cmd, string2: main_cmds.names[i]->name, swap_penalty: 0, substition_penalty: 2, insertion_penalty: 1, deletion_penalty: 4);
80
81 qsort(main_cmds.names, main_cmds.cnt,
82 sizeof(*main_cmds.names), levenshtein_compare);
83
84 best_similarity = main_cmds.names[0]->len;
85 n = 1;
86 while (n < main_cmds.cnt && best_similarity == main_cmds.names[n]->len)
87 ++n;
88 }
89
90 if (autocorrect && n == 1) {
91 const char *assumed = main_cmds.names[0]->name;
92
93 main_cmds.names[0] = NULL;
94 clean_cmdnames(&main_cmds);
95 clean_cmdnames(&other_cmds);
96 fprintf(stderr, "WARNING: You called a perf program named '%s', "
97 "which does not exist.\n"
98 "Continuing under the assumption that you meant '%s'\n",
99 cmd, assumed);
100 if (autocorrect > 0) {
101 fprintf(stderr, "in %0.1f seconds automatically...\n",
102 (float)autocorrect/10.0);
103 poll(NULL, 0, autocorrect * 100);
104 }
105 return assumed;
106 }
107
108 fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
109
110 if (main_cmds.cnt && best_similarity < 6) {
111 fprintf(stderr, "\nDid you mean %s?\n",
112 n < 2 ? "this": "one of these");
113
114 for (i = 0; i < n; i++)
115 fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
116 }
117end:
118 clean_cmdnames(&main_cmds);
119 clean_cmdnames(&other_cmds);
120 exit(1);
121}
122

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