LXR linux/tools/perf/util/help-unknown-cmd.c

   1#include "cache.h"
   2#include "config.h"
   3#include <stdio.h>
   4#include <subcmd/help.h>
   5#include "../builtin.h"
   6#include "levenshtein.h"
   7
   8static int autocorrect;
   9static struct cmdnames aliases;
  10
  11static int perf_unknown_cmd_config(const char *var, const char *value,
  12                                   void *cb __maybe_unused)
  13{
  14        if (!strcmp(var, "help.autocorrect"))
  15                autocorrect = perf_config_int(var,value);
  16        /* Also use aliases for command lookup */
  17        if (!prefixcmp(var, "alias."))
  18                add_cmdname(&aliases, var + 6, strlen(var + 6));
  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        memset(&aliases, 0, sizeof(aliases));
  63
  64        perf_config(perf_unknown_cmd_config, NULL);
  65
  66        load_command_list("perf-", &main_cmds, &other_cmds);
  67
  68        if (add_cmd_list(&main_cmds, &aliases) < 0 ||
  69            add_cmd_list(&main_cmds, &other_cmds) < 0) {
  70                fprintf(stderr, "ERROR: Failed to allocate command list for unknown command.\n");
  71                goto end;
  72        }
  73        qsort(main_cmds.names, main_cmds.cnt,
  74              sizeof(main_cmds.names), cmdname_compare);
  75        uniq(&main_cmds);
  76
  77        if (main_cmds.cnt) {
  78                /* This reuses cmdname->len for similarity index */
  79                for (i = 0; i < main_cmds.cnt; ++i)
  80                        main_cmds.names[i]->len =
  81                                levenshtein(cmd, main_cmds.names[i]->name, 0, 2, 1, 4);
  82
  83                qsort(main_cmds.names, main_cmds.cnt,
  84                      sizeof(*main_cmds.names), levenshtein_compare);
  85
  86                best_similarity = main_cmds.names[0]->len;
  87                n = 1;
  88                while (n < main_cmds.cnt && best_similarity == main_cmds.names[n]->len)
  89                        ++n;
  90        }
  91
  92        if (autocorrect && n == 1) {
  93                const char *assumed = main_cmds.names[0]->name;
  94
  95                main_cmds.names[0] = NULL;
  96                clean_cmdnames(&main_cmds);
  97                fprintf(stderr, "WARNING: You called a perf program named '%s', "
  98                        "which does not exist.\n"
  99                        "Continuing under the assumption that you meant '%s'\n",
 100                        cmd, assumed);
 101                if (autocorrect > 0) {
 102                        fprintf(stderr, "in %0.1f seconds automatically...\n",
 103                                (float)autocorrect/10.0);
 104                        poll(NULL, 0, autocorrect * 100);
 105                }
 106                return assumed;
 107        }
 108
 109        fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
 110
 111        if (main_cmds.cnt && best_similarity < 6) {
 112                fprintf(stderr, "\nDid you mean %s?\n",
 113                        n < 2 ? "this": "one of these");
 114
 115                for (i = 0; i < n; i++)
 116                        fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 117        }
 118end:
 119        exit(1);
 120}
 121