1
linux/tools/perf/util/help-unknown-cmd.c
Ian Rogers 7aea01eaf4 perf help: Lower levenshtein penality for deleting character
The levenshtein penalty for deleting a character was far higher than
subsituting or inserting a character. Lower the penalty to match that
of inserting a character.

Before:

  $ perf recccord
  perf: 'recccord' is not a perf-command. See 'perf --help'.
  $

After:

  $ perf recccord
  perf: 'recccord' is not a perf-command. See 'perf --help'.

  Did you mean this?
          record
  $

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240301201306.2680986-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-03-21 13:54:40 -03:00

123 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include "cache.h"
#include "config.h"
#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <subcmd/help.h>
#include "../builtin.h"
#include "levenshtein.h"
#include <linux/zalloc.h>
static int autocorrect;
static int perf_unknown_cmd_config(const char *var, const char *value,
void *cb __maybe_unused)
{
if (!strcmp(var, "help.autocorrect"))
return perf_config_int(&autocorrect, var,value);
return 0;
}
static int levenshtein_compare(const void *p1, const void *p2)
{
const struct cmdname *const *c1 = p1, *const *c2 = p2;
const char *s1 = (*c1)->name, *s2 = (*c2)->name;
int l1 = (*c1)->len;
int l2 = (*c2)->len;
return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
}
static int add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
{
unsigned int i, nr = cmds->cnt + old->cnt;
void *tmp;
if (nr > cmds->alloc) {
/* Choose bigger one to alloc */
if (alloc_nr(cmds->alloc) < nr)
cmds->alloc = nr;
else
cmds->alloc = alloc_nr(cmds->alloc);
tmp = realloc(cmds->names, cmds->alloc * sizeof(*cmds->names));
if (!tmp)
return -1;
cmds->names = tmp;
}
for (i = 0; i < old->cnt; i++)
cmds->names[cmds->cnt++] = old->names[i];
zfree(&old->names);
old->cnt = 0;
return 0;
}
const char *help_unknown_cmd(const char *cmd, struct cmdnames *main_cmds)
{
unsigned int i, n = 0, best_similarity = 0;
struct cmdnames other_cmds;
memset(&other_cmds, 0, sizeof(other_cmds));
perf_config(perf_unknown_cmd_config, NULL);
load_command_list("perf-", main_cmds, &other_cmds);
if (add_cmd_list(main_cmds, &other_cmds) < 0) {
fprintf(stderr, "ERROR: Failed to allocate command list for unknown command.\n");
goto end;
}
qsort(main_cmds->names, main_cmds->cnt,
sizeof(main_cmds->names), cmdname_compare);
uniq(main_cmds);
if (main_cmds->cnt) {
/* This reuses cmdname->len for similarity index */
for (i = 0; i < main_cmds->cnt; ++i) {
main_cmds->names[i]->len =
levenshtein(cmd, main_cmds->names[i]->name,
/*swap_penalty=*/0,
/*substition_penality=*/2,
/*insertion_penality=*/1,
/*deletion_penalty=*/1);
}
qsort(main_cmds->names, main_cmds->cnt,
sizeof(*main_cmds->names), levenshtein_compare);
best_similarity = main_cmds->names[0]->len;
n = 1;
while (n < main_cmds->cnt && best_similarity == main_cmds->names[n]->len)
++n;
}
if (autocorrect && n == 1) {
const char *assumed = main_cmds->names[0]->name;
main_cmds->names[0] = NULL;
clean_cmdnames(&other_cmds);
fprintf(stderr, "WARNING: You called a perf program named '%s', "
"which does not exist.\n"
"Continuing under the assumption that you meant '%s'\n",
cmd, assumed);
if (autocorrect > 0) {
fprintf(stderr, "in %0.1f seconds automatically...\n",
(float)autocorrect/10.0);
poll(NULL, 0, autocorrect * 100);
}
return assumed;
}
fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
if (main_cmds->cnt && best_similarity < 6) {
fprintf(stderr, "\nDid you mean %s?\n",
n < 2 ? "this": "one of these");
for (i = 0; i < n; i++)
fprintf(stderr, "\t%s\n", main_cmds->names[i]->name);
}
end:
clean_cmdnames(&other_cmds);
return NULL;
}