linux/tools/perf/util/help.c
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   1#include "cache.h"
   2#include "../builtin.h"
   3#include "exec_cmd.h"
   4#include "levenshtein.h"
   5#include "help.h"
   6
   7/* most GUI terminals set COLUMNS (although some don't export it) */
   8static int term_columns(void)
   9{
  10        char *col_string = getenv("COLUMNS");
  11        int n_cols;
  12
  13        if (col_string && (n_cols = atoi(col_string)) > 0)
  14                return n_cols;
  15
  16#ifdef TIOCGWINSZ
  17        {
  18                struct winsize ws;
  19                if (!ioctl(1, TIOCGWINSZ, &ws)) {
  20                        if (ws.ws_col)
  21                                return ws.ws_col;
  22                }
  23        }
  24#endif
  25
  26        return 80;
  27}
  28
  29void add_cmdname(struct cmdnames *cmds, const char *name, size_t len)
  30{
  31        struct cmdname *ent = malloc(sizeof(*ent) + len + 1);
  32
  33        ent->len = len;
  34        memcpy(ent->name, name, len);
  35        ent->name[len] = 0;
  36
  37        ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
  38        cmds->names[cmds->cnt++] = ent;
  39}
  40
  41static void clean_cmdnames(struct cmdnames *cmds)
  42{
  43        unsigned int i;
  44
  45        for (i = 0; i < cmds->cnt; ++i)
  46                free(cmds->names[i]);
  47        free(cmds->names);
  48        cmds->cnt = 0;
  49        cmds->alloc = 0;
  50}
  51
  52static int cmdname_compare(const void *a_, const void *b_)
  53{
  54        struct cmdname *a = *(struct cmdname **)a_;
  55        struct cmdname *b = *(struct cmdname **)b_;
  56        return strcmp(a->name, b->name);
  57}
  58
  59static void uniq(struct cmdnames *cmds)
  60{
  61        unsigned int i, j;
  62
  63        if (!cmds->cnt)
  64                return;
  65
  66        for (i = j = 1; i < cmds->cnt; i++)
  67                if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
  68                        cmds->names[j++] = cmds->names[i];
  69
  70        cmds->cnt = j;
  71}
  72
  73void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
  74{
  75        size_t ci, cj, ei;
  76        int cmp;
  77
  78        ci = cj = ei = 0;
  79        while (ci < cmds->cnt && ei < excludes->cnt) {
  80                cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
  81                if (cmp < 0)
  82                        cmds->names[cj++] = cmds->names[ci++];
  83                else if (cmp == 0)
  84                        ci++, ei++;
  85                else if (cmp > 0)
  86                        ei++;
  87        }
  88
  89        while (ci < cmds->cnt)
  90                cmds->names[cj++] = cmds->names[ci++];
  91
  92        cmds->cnt = cj;
  93}
  94
  95static void pretty_print_string_list(struct cmdnames *cmds, int longest)
  96{
  97        int cols = 1, rows;
  98        int space = longest + 1; /* min 1 SP between words */
  99        int max_cols = term_columns() - 1; /* don't print *on* the edge */
 100        int i, j;
 101
 102        if (space < max_cols)
 103                cols = max_cols / space;
 104        rows = (cmds->cnt + cols - 1) / cols;
 105
 106        for (i = 0; i < rows; i++) {
 107                printf("  ");
 108
 109                for (j = 0; j < cols; j++) {
 110                        unsigned int n = j * rows + i;
 111                        unsigned int size = space;
 112
 113                        if (n >= cmds->cnt)
 114                                break;
 115                        if (j == cols-1 || n + rows >= cmds->cnt)
 116                                size = 1;
 117                        printf("%-*s", size, cmds->names[n]->name);
 118                }
 119                putchar('\n');
 120        }
 121}
 122
 123static int is_executable(const char *name)
 124{
 125        struct stat st;
 126
 127        if (stat(name, &st) || /* stat, not lstat */
 128            !S_ISREG(st.st_mode))
 129                return 0;
 130
 131        return st.st_mode & S_IXUSR;
 132}
 133
 134static void list_commands_in_dir(struct cmdnames *cmds,
 135                                         const char *path,
 136                                         const char *prefix)
 137{
 138        int prefix_len;
 139        DIR *dir = opendir(path);
 140        struct dirent *de;
 141        struct strbuf buf = STRBUF_INIT;
 142        int len;
 143
 144        if (!dir)
 145                return;
 146        if (!prefix)
 147                prefix = "perf-";
 148        prefix_len = strlen(prefix);
 149
 150        strbuf_addf(&buf, "%s/", path);
 151        len = buf.len;
 152
 153        while ((de = readdir(dir)) != NULL) {
 154                int entlen;
 155
 156                if (prefixcmp(de->d_name, prefix))
 157                        continue;
 158
 159                strbuf_setlen(&buf, len);
 160                strbuf_addstr(&buf, de->d_name);
 161                if (!is_executable(buf.buf))
 162                        continue;
 163
 164                entlen = strlen(de->d_name) - prefix_len;
 165                if (has_extension(de->d_name, ".exe"))
 166                        entlen -= 4;
 167
 168                add_cmdname(cmds, de->d_name + prefix_len, entlen);
 169        }
 170        closedir(dir);
 171        strbuf_release(&buf);
 172}
 173
 174void load_command_list(const char *prefix,
 175                struct cmdnames *main_cmds,
 176                struct cmdnames *other_cmds)
 177{
 178        const char *env_path = getenv("PATH");
 179        const char *exec_path = perf_exec_path();
 180
 181        if (exec_path) {
 182                list_commands_in_dir(main_cmds, exec_path, prefix);
 183                qsort(main_cmds->names, main_cmds->cnt,
 184                      sizeof(*main_cmds->names), cmdname_compare);
 185                uniq(main_cmds);
 186        }
 187
 188        if (env_path) {
 189                char *paths, *path, *colon;
 190                path = paths = strdup(env_path);
 191                while (1) {
 192                        if ((colon = strchr(path, PATH_SEP)))
 193                                *colon = 0;
 194                        if (!exec_path || strcmp(path, exec_path))
 195                                list_commands_in_dir(other_cmds, path, prefix);
 196
 197                        if (!colon)
 198                                break;
 199                        path = colon + 1;
 200                }
 201                free(paths);
 202
 203                qsort(other_cmds->names, other_cmds->cnt,
 204                      sizeof(*other_cmds->names), cmdname_compare);
 205                uniq(other_cmds);
 206        }
 207        exclude_cmds(other_cmds, main_cmds);
 208}
 209
 210void list_commands(const char *title, struct cmdnames *main_cmds,
 211                   struct cmdnames *other_cmds)
 212{
 213        unsigned int i, longest = 0;
 214
 215        for (i = 0; i < main_cmds->cnt; i++)
 216                if (longest < main_cmds->names[i]->len)
 217                        longest = main_cmds->names[i]->len;
 218        for (i = 0; i < other_cmds->cnt; i++)
 219                if (longest < other_cmds->names[i]->len)
 220                        longest = other_cmds->names[i]->len;
 221
 222        if (main_cmds->cnt) {
 223                const char *exec_path = perf_exec_path();
 224                printf("available %s in '%s'\n", title, exec_path);
 225                printf("----------------");
 226                mput_char('-', strlen(title) + strlen(exec_path));
 227                putchar('\n');
 228                pretty_print_string_list(main_cmds, longest);
 229                putchar('\n');
 230        }
 231
 232        if (other_cmds->cnt) {
 233                printf("%s available from elsewhere on your $PATH\n", title);
 234                printf("---------------------------------------");
 235                mput_char('-', strlen(title));
 236                putchar('\n');
 237                pretty_print_string_list(other_cmds, longest);
 238                putchar('\n');
 239        }
 240}
 241
 242int is_in_cmdlist(struct cmdnames *c, const char *s)
 243{
 244        unsigned int i;
 245
 246        for (i = 0; i < c->cnt; i++)
 247                if (!strcmp(s, c->names[i]->name))
 248                        return 1;
 249        return 0;
 250}
 251
 252static int autocorrect;
 253static struct cmdnames aliases;
 254
 255static int perf_unknown_cmd_config(const char *var, const char *value, void *cb)
 256{
 257        if (!strcmp(var, "help.autocorrect"))
 258                autocorrect = perf_config_int(var,value);
 259        /* Also use aliases for command lookup */
 260        if (!prefixcmp(var, "alias."))
 261                add_cmdname(&aliases, var + 6, strlen(var + 6));
 262
 263        return perf_default_config(var, value, cb);
 264}
 265
 266static int levenshtein_compare(const void *p1, const void *p2)
 267{
 268        const struct cmdname *const *c1 = p1, *const *c2 = p2;
 269        const char *s1 = (*c1)->name, *s2 = (*c2)->name;
 270        int l1 = (*c1)->len;
 271        int l2 = (*c2)->len;
 272        return l1 != l2 ? l1 - l2 : strcmp(s1, s2);
 273}
 274
 275static void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
 276{
 277        unsigned int i;
 278
 279        ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);
 280
 281        for (i = 0; i < old->cnt; i++)
 282                cmds->names[cmds->cnt++] = old->names[i];
 283        free(old->names);
 284        old->cnt = 0;
 285        old->names = NULL;
 286}
 287
 288const char *help_unknown_cmd(const char *cmd)
 289{
 290        unsigned int i, n = 0, best_similarity = 0;
 291        struct cmdnames main_cmds, other_cmds;
 292
 293        memset(&main_cmds, 0, sizeof(main_cmds));
 294        memset(&other_cmds, 0, sizeof(main_cmds));
 295        memset(&aliases, 0, sizeof(aliases));
 296
 297        perf_config(perf_unknown_cmd_config, NULL);
 298
 299        load_command_list("perf-", &main_cmds, &other_cmds);
 300
 301        add_cmd_list(&main_cmds, &aliases);
 302        add_cmd_list(&main_cmds, &other_cmds);
 303        qsort(main_cmds.names, main_cmds.cnt,
 304              sizeof(main_cmds.names), cmdname_compare);
 305        uniq(&main_cmds);
 306
 307        if (main_cmds.cnt) {
 308                /* This reuses cmdname->len for similarity index */
 309                for (i = 0; i < main_cmds.cnt; ++i)
 310                        main_cmds.names[i]->len =
 311                                levenshtein(cmd, main_cmds.names[i]->name, 0, 2, 1, 4);
 312
 313                qsort(main_cmds.names, main_cmds.cnt,
 314                      sizeof(*main_cmds.names), levenshtein_compare);
 315
 316                best_similarity = main_cmds.names[0]->len;
 317                n = 1;
 318                while (n < main_cmds.cnt && best_similarity == main_cmds.names[n]->len)
 319                        ++n;
 320        }
 321
 322        if (autocorrect && n == 1) {
 323                const char *assumed = main_cmds.names[0]->name;
 324
 325                main_cmds.names[0] = NULL;
 326                clean_cmdnames(&main_cmds);
 327                fprintf(stderr, "WARNING: You called a Git program named '%s', "
 328                        "which does not exist.\n"
 329                        "Continuing under the assumption that you meant '%s'\n",
 330                        cmd, assumed);
 331                if (autocorrect > 0) {
 332                        fprintf(stderr, "in %0.1f seconds automatically...\n",
 333                                (float)autocorrect/10.0);
 334                        poll(NULL, 0, autocorrect * 100);
 335                }
 336                return assumed;
 337        }
 338
 339        fprintf(stderr, "perf: '%s' is not a perf-command. See 'perf --help'.\n", cmd);
 340
 341        if (main_cmds.cnt && best_similarity < 6) {
 342                fprintf(stderr, "\nDid you mean %s?\n",
 343                        n < 2 ? "this": "one of these");
 344
 345                for (i = 0; i < n; i++)
 346                        fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
 347        }
 348
 349        exit(1);
 350}
 351
 352int cmd_version(int argc __used, const char **argv __used, const char *prefix __used)
 353{
 354        printf("perf version %s\n", perf_version_string);
 355        return 0;
 356}
 357