help.c

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#include "cache.h"
#include "../builtin.h"
#include "exec_cmd.h"
#include "levenshtein.h"
#include "help.h"
#include <termios.h>

void add_cmdname(struct cmdnames *cmds, const char *name, size_t len)
{
    struct cmdname *ent = malloc(sizeof(*ent) + len + 1);

    ent->len = len;
    memcpy(ent->name, name, len);
    ent->name[len] = 0;

    ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
    cmds->names[cmds->cnt++] = ent;
}

static void clean_cmdnames(struct cmdnames *cmds)
{
    unsigned int i;

    for (i = 0; i < cmds->cnt; ++i)
        free(cmds->names[i]);
    free(cmds->names);
    cmds->cnt = 0;
    cmds->alloc = 0;
}

static int cmdname_compare(const void *a_, const void *b_)
{
    struct cmdname *a = *(struct cmdname **)a_;
    struct cmdname *b = *(struct cmdname **)b_;
    return strcmp(a->name, b->name);
}

static void uniq(struct cmdnames *cmds)
{
    unsigned int i, j;

    if (!cmds->cnt)
        return;

    for (i = j = 1; i < cmds->cnt; i++)
        if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
            cmds->names[j++] = cmds->names[i];

    cmds->cnt = j;
}

void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes)
{
    size_t ci, cj, ei;
    int cmp;

    ci = cj = ei = 0;
    while (ci < cmds->cnt && ei < excludes->cnt) {
        cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
        if (cmp < 0)
            cmds->names[cj++] = cmds->names[ci++];
        else if (cmp == 0)
            ci++, ei++;
        else if (cmp > 0)
            ei++;
    }

    while (ci < cmds->cnt)
        cmds->names[cj++] = cmds->names[ci++];

    cmds->cnt = cj;
}

static void pretty_print_string_list(struct cmdnames *cmds, int longest)
{
    int cols = 1, rows;
    int space = longest + 1; /* min 1 SP between words */
    struct winsize win;
    int max_cols;
    int i, j;

    get_term_dimensions(&win);
    max_cols = win.ws_col - 1; /* don't print *on* the edge */

    if (space < max_cols)
        cols = max_cols / space;
    rows = (cmds->cnt + cols - 1) / cols;

    for (i = 0; i < rows; i++) {
        printf("  ");

        for (j = 0; j < cols; j++) {
            unsigned int n = j * rows + i;
            unsigned int size = space;

            if (n >= cmds->cnt)
                break;
            if (j == cols-1 || n + rows >= cmds->cnt)
                size = 1;
            printf("%-*s", size, cmds->names[n]->name);
        }
        putchar('\n');
    }
}

static int is_executable(const char *name)
{
    struct stat st;

    if (stat(name, &st) || /* stat, not lstat */
        !S_ISREG(st.st_mode))
        return 0;

    return st.st_mode & S_IXUSR;
}

static void list_commands_in_dir(struct cmdnames *cmds,
                     const char *path,
                     const char *prefix)
{
    int prefix_len;
    DIR *dir = opendir(path);
    struct dirent *de;
    struct strbuf buf = STRBUF_INIT;
    int len;

    if (!dir)
        return;
    if (!prefix)
        prefix = "perf-";
    prefix_len = strlen(prefix);

    strbuf_addf(&buf, "%s/", path);
    len = buf.len;

    while ((de = readdir(dir)) != NULL) {
        int entlen;

        if (prefixcmp(de->d_name, prefix))
            continue;

        strbuf_setlen(&buf, len);
        strbuf_addstr(&buf, de->d_name);
        if (!is_executable(buf.buf))
            continue;

        entlen = strlen(de->d_name) - prefix_len;
        if (has_extension(de->d_name, ".exe"))
            entlen -= 4;

        add_cmdname(cmds, de->d_name + prefix_len, entlen);
    }
    closedir(dir);
    strbuf_release(&buf);
}

void load_command_list(const char *prefix,
        struct cmdnames *main_cmds,
        struct cmdnames *other_cmds)
{
    const char *env_path = getenv("PATH");
    const char *exec_path = perf_exec_path();

    if (exec_path) {
        list_commands_in_dir(main_cmds, exec_path, prefix);
        qsort(main_cmds->names, main_cmds->cnt,
              sizeof(*main_cmds->names), cmdname_compare);
        uniq(main_cmds);
    }

    if (env_path) {
        char *paths, *path, *colon;
        path = paths = strdup(env_path);
        while (1) {
            if ((colon = strchr(path, PATH_SEP)))
                *colon = 0;
            if (!exec_path || strcmp(path, exec_path))
                list_commands_in_dir(other_cmds, path, prefix);

            if (!colon)
                break;
            path = colon + 1;
        }
        free(paths);

        qsort(other_cmds->names, other_cmds->cnt,
              sizeof(*other_cmds->names), cmdname_compare);
        uniq(other_cmds);
    }
    exclude_cmds(other_cmds, main_cmds);
}

void list_commands(const char *title, struct cmdnames *main_cmds,
           struct cmdnames *other_cmds)
{
    unsigned int i, longest = 0;

    for (i = 0; i < main_cmds->cnt; i++)
        if (longest < main_cmds->names[i]->len)
            longest = main_cmds->names[i]->len;
    for (i = 0; i < other_cmds->cnt; i++)
        if (longest < other_cmds->names[i]->len)
            longest = other_cmds->names[i]->len;

    if (main_cmds->cnt) {
        const char *exec_path = perf_exec_path();
        printf("available %s in '%s'\n", title, exec_path);
        printf("----------------");
        mput_char('-', strlen(title) + strlen(exec_path));
        putchar('\n');
        pretty_print_string_list(main_cmds, longest);
        putchar('\n');
    }

    if (other_cmds->cnt) {
        printf("%s available from elsewhere on your $PATH\n", title);
        printf("---------------------------------------");
        mput_char('-', strlen(title));
        putchar('\n');
        pretty_print_string_list(other_cmds, longest);
        putchar('\n');
    }
}

int is_in_cmdlist(struct cmdnames *c, const char *s)
{
    unsigned int i;

    for (i = 0; i < c->cnt; i++)
        if (!strcmp(s, c->names[i]->name))
            return 1;
    return 0;
}

static int autocorrect;
static struct cmdnames aliases;

static int perf_unknown_cmd_config(const char *var, const char *value, void *cb)
{
    if (!strcmp(var, "help.autocorrect"))
        autocorrect = perf_config_int(var,value);
    /* Also use aliases for command lookup */
    if (!prefixcmp(var, "alias."))
        add_cmdname(&aliases, var + 6, strlen(var + 6));

    return perf_default_config(var, value, cb);
}

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 void add_cmd_list(struct cmdnames *cmds, struct cmdnames *old)
{
    unsigned int i;

    ALLOC_GROW(cmds->names, cmds->cnt + old->cnt, cmds->alloc);

    for (i = 0; i < old->cnt; i++)
        cmds->names[cmds->cnt++] = old->names[i];
    free(old->names);
    old->cnt = 0;
    old->names = NULL;
}

const char *help_unknown_cmd(const char *cmd)
{
    unsigned int i, n = 0, best_similarity = 0;
    struct cmdnames main_cmds, other_cmds;

    memset(&main_cmds, 0, sizeof(main_cmds));
    memset(&other_cmds, 0, sizeof(main_cmds));
    memset(&aliases, 0, sizeof(aliases));

    perf_config(perf_unknown_cmd_config, NULL);

    load_command_list("perf-", &main_cmds, &other_cmds);

    add_cmd_list(&main_cmds, &aliases);
    add_cmd_list(&main_cmds, &other_cmds);
    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, 0, 2, 1, 4);

        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(&main_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);
    }

    exit(1);
}

int cmd_version(int argc __maybe_unused, const char **argv __maybe_unused,
        const char *prefix __maybe_unused)
{
    printf("perf version %s\n", perf_version_string);
    return 0;
}