Quelle  help-unknown-cmd.c   Sprache: 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;
}