shared.c

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/***********************************************************************
 Freeciv - Copyright (C) 1996 - A Kjeldberg, L Gregersen, P Unold
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
***********************************************************************/
 
#ifdef HAVE_CONFIG_H
#include <fc_config.h>
#endif
 
#include "fc_prehdrs.h"
 
#ifdef FREECIV_HAVE_SYS_TYPES_H
/* Under Mac OS X sys/types.h must be included before dirent.h */
#include <sys/types.h>
#endif
 
#ifdef FREECIV_HAVE_DIRENT_H
#include <dirent.h>
#endif
 
#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
 
#ifdef HAVE_LOCALE_H
#include <locale.h>
#endif
 
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef FREECIV_MSWINDOWS
#include <windows.h>
#include <lmcons.h>     /* UNLEN */
#include <shlobj.h>
#ifdef HAVE_DIRECT_H
#include <direct.h>
#endif /* HAVE_DIRECT_H */
#endif /* FREECIV_MSWINDOWS */
 
/* utility */
#include "astring.h"
#include "fc_dirent.h"
#include "fciconv.h"
#include "fcintl.h"
#include "mem.h"
#include "rand.h"
#include "string_vector.h"
 
#include "shared.h"
 
/* If no default data path is defined use the default default one */
#ifndef DEFAULT_DATA_PATH
#define DEFAULT_DATA_PATH "." PATH_SEPARATOR \
                          "data" PATH_SEPARATOR \
                          FREECIV_STORAGE_DIR DIR_SEPARATOR DATASUBDIR
#endif
#ifndef DEFAULT_SAVE_PATH
#define DEFAULT_SAVE_PATH "." PATH_SEPARATOR \
                          FREECIV_STORAGE_DIR DIR_SEPARATOR "saves"
#endif
#ifndef DEFAULT_SCENARIO_PATH
#define DEFAULT_SCENARIO_PATH                          \
  "." PATH_SEPARATOR                                   \
  "data" DIR_SEPARATOR "scenarios" PATH_SEPARATOR                      \
  FREECIV_STORAGE_DIR DATASUBDIR DIR_SEPARATOR "scenarios" PATH_SEPARATOR \
  FREECIV_STORAGE_DIR DIR_SEPARATOR "scenarios"
#endif /* DEFAULT_SCENARIO_PATH */
 
/* environment */
#ifndef FREECIV_DATA_PATH
#define FREECIV_DATA_PATH "FREECIV_DATA_PATH"
#endif
#ifndef FREECIV_SAVE_PATH
#define FREECIV_SAVE_PATH "FREECIV_SAVE_PATH"
#endif
#ifndef FREECIV_SCENARIO_PATH
#define FREECIV_SCENARIO_PATH "FREECIV_SCENARIO_PATH"
#endif
 
/* Both of these are stored in the local encoding.  The grouping_sep must
 * be converted to the internal encoding when it's used. */
static char *grouping = NULL;
static char *grouping_sep = NULL;
 
/* As well as base64 functions, this string is used for checking for
 * 'safe' filenames, so should not contain / \ . */
static const char base64url[] =
  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
 
static struct strvec *data_dir_names = NULL;
static struct strvec *save_dir_names = NULL;
static struct strvec *scenario_dir_names = NULL;
 
static char *mc_group = NULL;
static char *home_dir_user = NULL;
static char *storage_dir_freeciv = NULL;
 
static struct astring realfile = ASTRING_INIT;
 
static int compare_file_mtime_ptrs(const struct fileinfo *const *ppa,
                                   const struct fileinfo *const *ppb);
 
static char *expand_dir(char *tok_in, bool ok_to_free);
 
/************************************************************************/
enum fc_tristate fc_tristate_and(enum fc_tristate one, enum fc_tristate two)
{
  if (TRI_NO == one || TRI_NO == two) {
    return TRI_NO;
  }
 
  if (TRI_MAYBE == one || TRI_MAYBE == two) {
    return TRI_MAYBE;
  }
 
  return TRI_YES;
}
 
/************************************************************************/
enum fc_tristate fc_tristate_or(enum fc_tristate one, enum fc_tristate two)
{
  if (TRI_YES == one || TRI_YES == two) {
    return TRI_YES;
  }
 
  if (TRI_MAYBE == one || TRI_MAYBE == two) {
    return TRI_MAYBE;
  }
 
  return TRI_NO;
}
 
/************************************************************************/
const char *big_int_to_text(unsigned int mantissa, unsigned int exponent)
{
  static char buf[64]; /* Note that we'll be filling this in right to left. */
  char *grp = grouping;
  char *ptr;
  unsigned int cnt = 0;
  char sep[64];
  size_t seplen;
 
  /* We have to convert the encoding here (rather than when the locale
   * is initialized) because it can't be done before the charsets are
   * initialized. */
  local_to_internal_string_buffer(grouping_sep, sep, sizeof(sep));
  seplen = strlen(sep);
 
#if 0 /* Not needed while the values are unsigned. */
  fc_assert_ret_val(0 <= mantissa, NULL);
  fc_assert_ret_val(0 <= exponent, NULL);
#endif
 
  if (mantissa == 0) {
    return "0";
  }
 
  /* We fill the string in backwards, starting from the right.  So the first
   * thing we do is terminate it. */
  ptr = &buf[sizeof(buf)];
  *(--ptr) = '\0';
 
  while (mantissa != 0) {
    int dig;
 
    if (ptr <= buf + seplen) {
      /* Avoid a buffer overflow. */
      fc_assert_ret_val(ptr > buf + seplen, NULL);
      return ptr;
    }
 
    /* Add on another character. */
    if (exponent > 0) {
      dig = 0;
      exponent--;
    } else {
      dig = mantissa % 10;
      mantissa /= 10;
    }
    *(--ptr) = '0' + dig;
 
    cnt++;
    if (mantissa != 0 && cnt == *grp) {
      /* Reached count of digits in group: insert separator and reset count. */
      cnt = 0;
      if (*grp == CHAR_MAX) {
        /* This test is unlikely to be necessary since we would need at
           least 421-bit ints to break the 127 digit barrier, but why not. */
        break;
      }
      ptr -= seplen;
      fc_assert_ret_val(ptr >= buf, NULL);
      memcpy(ptr, sep, seplen);
      if (*(grp + 1) != 0) {
        /* Zero means to repeat the present group-size indefinitely. */
        grp++;
      }
    }
  }
 
  return ptr;
}
 
 
/************************************************************************/
const char *int_to_text(unsigned int number)
{
  return big_int_to_text(number, 0);
}
 
/************************************************************************/
static bool is_ascii(char ch)
{
  /* this works with both signed and unsigned char's. */
  return ch >= ' ' && ch <= '~';
}
 
/************************************************************************/
bool is_safe_filename(const char *name)
{
  int i = 0;
 
  /* must not be NULL or empty */
  if (!name || *name == '\0') {
    return FALSE;
  }
 
  for (; '\0' != name[i]; i++) {
    if ('.' != name[i] && NULL == strchr(base64url, name[i])) {
      return FALSE;
    }
  }
 
  /* we don't allow the filename to ascend directories */
  if (strstr(name, PARENT_DIR_OPERATOR)) {
    return FALSE;
  }
 
  /* Otherwise, it is okay... */
  return TRUE;
}
 
/************************************************************************/
bool is_ascii_name(const char *name)
{
  const char illegal_chars[] = {'|', '%', '"', ',', '*', '<', '>', '\0'};
  int i, j;
 
  /* must not be NULL or empty */
  if (!name || *name == '\0') {
    return FALSE;
  }
 
  /* must begin and end with some non-space character */
  if ((*name == ' ') || (*(strchr(name, '\0') - 1) == ' ')) {
    return FALSE;
  }
 
  /* must be composed entirely of printable ascii characters,
   * and no illegal characters which can break ranking scripts. */
  for (i = 0; name[i]; i++) {
    if (!is_ascii(name[i])) {
      return FALSE;
    }
    for (j = 0; illegal_chars[j]; j++) {
      if (name[i] == illegal_chars[j]) {
        return FALSE;
      }
    }
  }
 
  /* otherwise, it's okay... */
  return TRUE;
}
 
/************************************************************************/
bool is_base64url(const char *s)
{
  size_t i = 0;
 
  /* must not be NULL or empty */
  if (NULL == s || '\0' == *s) {
    return FALSE;
  }
 
  for (; '\0' != s[i]; i++) {
    if (NULL == strchr(base64url, s[i])) {
      return FALSE;
    }
  }
  return TRUE;
}
 
/************************************************************************/
void randomize_base64url_string(char *s, size_t n)
{
  size_t i = 0;
 
  /* must not be NULL or too short */
  if (NULL == s || 1 > n) {
    return;
  }
 
  for (; i < (n - 1); i++) {
    s[i] = base64url[fc_rand(sizeof(base64url) - 1)];
  }
  s[i] = '\0';
}
 
/************************************************************************/
int compare_strings(const void *first, const void *second)
{
  return fc_strcoll((const char *) first, (const char *) second);
}
 
/************************************************************************/
int compare_strings_ptrs(const void *first, const void *second)
{
  return fc_strcoll(*((const char **) first), *((const char **) second));
}
 
/************************************************************************/
int compare_strings_strvec(const char *const *first,
                           const char *const *second)
{
  return fc_strcoll(*first, *second);
}
 
/************************************************************************/
char *skip_leading_spaces(char *s)
{
  fc_assert_ret_val(NULL != s, NULL);
 
  while (*s != '\0' && fc_isspace(*s)) {
    s++;
  }
 
  return s;
}
 
/************************************************************************/
void remove_leading_spaces(char *s)
{
  char *t;
 
  fc_assert_ret(NULL != s);
  t = skip_leading_spaces(s);
  if (t != s) {
    while (*t != '\0') {
      *s++ = *t++;
    }
    *s = '\0';
  }
}
 
/************************************************************************/
void remove_trailing_spaces(char *s)
{
  char *t;
  size_t len;
 
  fc_assert_ret(NULL != s);
  len = strlen(s);
  if (len > 0) {
    t = s + len -1;
    while (fc_isspace(*t)) {
      *t = '\0';
      if (t == s) {
        break;
      }
      t--;
    }
  }
}
 
/************************************************************************/
void remove_leading_trailing_spaces(char *s)
{
  remove_leading_spaces(s);
  remove_trailing_spaces(s);
}
 
/************************************************************************/
static void remove_trailing_char(char *s, char trailing)
{
  char *t;
 
  fc_assert_ret(NULL != s);
 
  t = s + strlen(s) -1;
  while (t>=s && (*t) == trailing) {
    *t = '\0';
    t--;
  }
}
 
/************************************************************************/
char *end_of_strn(char *str, int *nleft)
{
  int len = strlen(str);
  *nleft -= len;
  fc_assert_ret_val(0 < (*nleft), NULL); /* space for the terminating nul */
  return str + len;
}
 
/************************************************************************/
bool check_strlen(const char *str, size_t len, const char *errmsg)
{
  fc_assert_ret_val_msg(strlen(str) < len, TRUE, errmsg, str, len);
  return FALSE;
}
 
/************************************************************************/
size_t loud_strlcpy(char *buffer, const char *str, size_t len,
                    const char *errmsg)
{
  (void) check_strlen(str, len, errmsg);
  return fc_strlcpy(buffer, str, len);
}
 
/************************************************************************/
bool str_to_int(const char *str, int *pint)
{
  const char *start;
 
  fc_assert_ret_val(NULL != str, FALSE);
 
  while (fc_isspace(*str)) {
    /* Skip leading spaces. */
    str++;
  }
 
  start = str;
  if ('-' == *str || '+' == *str) {
    /* Handle sign. */
    str++;
  }
  while (fc_isdigit(*str)) {
    /* Digits. */
    str++;
  }
 
  while (fc_isspace(*str)) {
    /* Ignore trailing spaces. */
    str++;
  }
 
  return ('\0' == *str && (NULL == pint || 1 == sscanf(start, "%d", pint)));
}
 
/************************************************************************/
bool str_to_uint(const char *str, unsigned int *pint)
{
  const char *start;
 
  fc_assert_ret_val(NULL != str, FALSE);
 
  while (fc_isspace(*str)) {
    /* Skip leading spaces. */
    str++;
  }
 
  start = str;
  if ('+' == *str) {
    /* Handle sign. */
    str++;
  }
  while (fc_isdigit(*str)) {
    /* Digits. */
    str++;
  }
 
  while (fc_isspace(*str)) {
    /* Ignore trailing spaces. */
    str++;
  }
 
  return ('\0' == *str && (NULL == pint || 1 == sscanf(start, "%u", pint)));
}
 
/************************************************************************/
bool str_to_float(const char *str, float *pfloat)
{
  bool dot;
  const char *start;
 
  fc_assert_ret_val(NULL != str, FALSE);
 
  while (fc_isspace(*str)) {
    /* Skip leading spaces. */
    str++;
  }
 
  start = str;
 
  if ('-' == *str || '+' == *str) {
    /* Handle sign. */
    str++;
  }
  while (fc_isdigit(*str)) {
    /* Digits. */
    str++;
  }
 
  if (*str == '.') {
    dot = TRUE;
    str++;
 
    while (fc_isdigit(*str)) {
      /* Digits. */
      str++;
    }
  } else {
    dot = FALSE;
  }
 
  while (fc_isspace(*str)) {
    /* Ignore trailing spaces. */
    str++;
  }
 
  return ('\0' == *str && dot
          && (NULL == pfloat || 1 == sscanf(start, "%f", pfloat)));
}
 
/************************************************************************/
char *user_home_dir(void)
{
#ifdef AMIGA
  return "PROGDIR:";
#else  /* AMIGA */
 
#ifdef FREECIV_MSWINDOWS
#define HOMEVAR "APPDATA"
#else
#define HOMEVAR "HOME"
#endif
 
  if (home_dir_user == NULL) {
    char *env = getenv(HOMEVAR);
 
    if (env) {
      home_dir_user = fc_strdup(env);
      log_verbose(HOMEVAR " is %s", home_dir_user);
    } else {
      log_error("Could not find home directory (" HOMEVAR " is not set).");
      home_dir_user = NULL;
    }
  }
 
  return home_dir_user;
#endif /* AMIGA */
}
 
/************************************************************************/
void free_user_home_dir(void)
{
  if (home_dir_user != NULL) {
    free(home_dir_user);
    home_dir_user = NULL;
  }
}
 
/************************************************************************/
char *freeciv_storage_dir(void)
{
  if (storage_dir_freeciv == NULL) {
    storage_dir_freeciv = fc_malloc(strlen(FREECIV_STORAGE_DIR) + 1);
 
    strcpy(storage_dir_freeciv, FREECIV_STORAGE_DIR);
 
    storage_dir_freeciv = expand_dir(storage_dir_freeciv, TRUE);
 
    log_verbose(_("Storage dir is \"%s\"."), storage_dir_freeciv);
  }
 
  return storage_dir_freeciv;
}
 
/************************************************************************/
void free_freeciv_storage_dir(void)
{
  if (storage_dir_freeciv != NULL) {
    free(storage_dir_freeciv);
    storage_dir_freeciv = NULL;
  }
}
 
/************************************************************************/
char *user_username(char *buf, size_t bufsz)
{
  /* This function uses a number of different methods to try to find a
   * username.  This username then has to be truncated to bufsz
   * characters (including terminator) and checked for sanity.  Note that
   * truncating a sane name can leave you with an insane name under some
   * charsets. */
 
  /* If the environment variable $USER is present and sane, use it. */
  {
    char *env = getenv("USER");
 
    if (env) {
      fc_strlcpy(buf, env, bufsz);
      if (is_ascii_name(buf)) {
        log_verbose("USER username is %s", buf);
        return buf;
      }
    }
  }
 
#ifdef HAVE_GETPWUID
  /* Otherwise if getpwuid() is available we can use it to find the true
   * username. */
  {
    struct passwd *pwent = getpwuid(getuid());
 
    if (pwent) {
      fc_strlcpy(buf, pwent->pw_name, bufsz);
      if (is_ascii_name(buf)) {
        log_verbose("getpwuid username is %s", buf);
        return buf;
      }
    }
  }
#endif /* HAVE_GETPWUID */
 
#ifdef FREECIV_MSWINDOWS
  /* On windows the GetUserName function will give us the login name. */
  {
    char name[UNLEN + 1];
    DWORD length = sizeof(name);
 
    if (GetUserName(name, &length)) {
      fc_strlcpy(buf, name, bufsz);
      if (is_ascii_name(buf)) {
        log_verbose("GetUserName username is %s", buf);
        return buf;
      }
    }
  }
#endif /* FREECIV_MSWINDOWS */
 
#ifdef ALWAYS_ROOT
  fc_strlcpy(buf, "name", bufsz);
#else
  fc_snprintf(buf, bufsz, "name%d", (int) getuid());
#endif
  log_verbose("fake username is %s", buf);
  fc_assert(is_ascii_name(buf));
  return buf;
}
 
/************************************************************************/
static char *expand_dir(char *tok_in, bool ok_to_free)
{
  int i; /* strlen(tok), or -1 as flag */
  char *tok;
  char **ret = &tok; /* Return tok by default */
  char *allocated;
 
  tok = skip_leading_spaces(tok_in);
  remove_trailing_spaces(tok);
  if (strcmp(tok, DIR_SEPARATOR) != 0) {
    remove_trailing_char(tok, DIR_SEPARATOR_CHAR);
  }
 
  i = strlen(tok);
  if (tok[0] == '~') {
    if (i > 1 && tok[1] != DIR_SEPARATOR_CHAR) {
      log_error("For \"%s\" in path cannot expand '~'"
                " except as '~" DIR_SEPARATOR "'; ignoring", tok);
      i = 0;  /* skip this one */
    } else {
      char *home = user_home_dir();
 
      if (!home) {
        log_verbose("No HOME, skipping path component %s", tok);
        i = 0;
      } else {
        int len = strlen(home) + i;   /* +1 -1 */
 
        allocated = fc_malloc(len);
        ret = &allocated;
 
        fc_snprintf(allocated, len, "%s%s", home, tok + 1);
        i = -1;       /* flag to free tok below */
      }
    }
  }
 
  if (i != 0) {
    /* We could check whether the directory exists and
     * is readable etc?  Don't currently. */
    if (i == -1 && ok_to_free) {
      free(tok);
      tok = NULL;
    }
  }
 
  return *ret;
}
 
/************************************************************************/
static struct strvec *base_get_dirs(const char *dir_list)
{
  struct strvec *dirs = strvec_new();
  char *path, *tok;
 
  path = fc_strdup(dir_list);   /* something we can strtok */
  tok = strtok(path, PATH_SEPARATOR);
  do {
    char *dir = expand_dir(tok, FALSE);
 
    if (dir != NULL) {
      strvec_append(dirs, dir);
      if (dir != tok) {
        free(dir);
      }
    }
 
    tok = strtok(NULL, PATH_SEPARATOR);
  } while (tok);
 
  free(path);
  return dirs;
}
 
/************************************************************************/
void free_data_dir_names(void)
{
  if (data_dir_names != NULL) {
    strvec_destroy(data_dir_names);
    data_dir_names = NULL;
  }
  if (save_dir_names != NULL) {
    strvec_destroy(save_dir_names);
    save_dir_names = NULL;
  }
  if (scenario_dir_names != NULL) {
    strvec_destroy(scenario_dir_names);
    scenario_dir_names = NULL;
  }
}
 
/************************************************************************/
const struct strvec *get_data_dirs(void)
{
  /* The first time this function is called it will search and
   * allocate the directory listing.  Subsequently we will already
   * know the list and can just return it. */
  if (NULL == data_dir_names) {
    const char *path;
 
#ifdef FREECIV_APPIMAGE
    char default_data_path[5000];
 
    fc_snprintf(default_data_path, sizeof(default_data_path),
                FREECIV_STORAGE_DIR DIR_SEPARATOR DATASUBDIR
                PATH_SEPARATOR
                "%s/usr/share/freeciv",
                getenv("APPDIR"));
#else  /* FREECIV_APPIMAGE */
#define default_data_path DEFAULT_DATA_PATH
#endif /* FREECIV_APPIMAGE */
 
    if ((path = getenv(FREECIV_DATA_PATH)) && '\0' == path[0]) {
      /* TRANS: <FREECIV_DATA_PATH> configuration error */
      log_error(_("\"%s\" is set but empty; using default \"%s\" "
                 "data directories instead."),
                FREECIV_DATA_PATH, default_data_path);
      path = NULL;
    }
    data_dir_names = base_get_dirs(NULL != path ? path : default_data_path);
    strvec_remove_duplicate(data_dir_names, strcmp); /* Don't set a path both. */
    strvec_iterate(data_dir_names, dirname) {
      log_verbose("Data path component: %s", dirname);
    } strvec_iterate_end;
  }
 
  return data_dir_names;
}
 
/************************************************************************/
const struct strvec *get_save_dirs(void)
{
  /* The first time this function is called it will search and
   * allocate the directory listing.  Subsequently we will already
   * know the list and can just return it. */
  if (NULL == save_dir_names) {
    const char *path;
 
    if ((path = getenv(FREECIV_SAVE_PATH)) && '\0' == path[0]) {
      /* TRANS: <FREECIV_SAVE_PATH> configuration error */
      log_error(_("\"%s\" is set but empty; using default \"%s\" "
                  "save directories instead."),
                FREECIV_SAVE_PATH, DEFAULT_SAVE_PATH);
      path = NULL;
    }
    save_dir_names = base_get_dirs(NULL != path ? path : DEFAULT_SAVE_PATH);
    strvec_remove_duplicate(save_dir_names, strcmp); /* Don't set a path both. */
    strvec_iterate(save_dir_names, dirname) {
      log_verbose("Save path component: %s", dirname);
    } strvec_iterate_end;
  }
 
  return save_dir_names;
}
 
/************************************************************************/
const struct strvec *get_scenario_dirs(void)
{
  /* The first time this function is called it will search and
   * allocate the directory listing.  Subsequently we will already
   * know the list and can just return it. */
  if (NULL == scenario_dir_names) {
    const char *path;
 
#ifdef FREECIV_APPIMAGE
    char default_scenario_path[5000];
 
    fc_snprintf(default_scenario_path, sizeof(default_scenario_path),
                FREECIV_STORAGE_DIR DIR_SEPARATOR DATASUBDIR DIR_SEPARATOR "scenarios"
                PATH_SEPARATOR
                FREECIV_STORAGE_DIR DIR_SEPARATOR "scenarios"
                PATH_SEPARATOR
                "%s/usr/share/freeciv/scenarios",
                getenv("APPDIR"));
#else  /* FREECIV_APPIMAGE */
#define default_scenario_path DEFAULT_SCENARIO_PATH
#endif /* FREECIV_APPIMAGE */
 
    if ((path = getenv(FREECIV_SCENARIO_PATH)) && '\0' == path[0]) {
      /* TRANS: <FREECIV_SCENARIO_PATH> configuration error */
      log_error( _("\"%s\" is set but empty; using default \"%s\" "
                   "scenario directories instead."),
                 FREECIV_SCENARIO_PATH, default_scenario_path);
      path = NULL;
    }
    scenario_dir_names = base_get_dirs(NULL != path ? path : default_scenario_path);
    strvec_remove_duplicate(scenario_dir_names, strcmp);      /* Don't set a path both. */
    strvec_iterate(scenario_dir_names, dirname) {
      log_verbose("Scenario path component: %s", dirname);
    } strvec_iterate_end;
  }
 
  return scenario_dir_names;
}
 
/************************************************************************/
struct strvec *fileinfolist(const struct strvec *dirs, const char *suffix)
{
  struct strvec *files = strvec_new();
  size_t suffix_len = strlen(suffix);
 
  fc_assert_ret_val(!strchr(suffix, DIR_SEPARATOR_CHAR), NULL);
 
  if (NULL == dirs) {
    return files;
  }
 
  /* First assemble a full list of names. */
  strvec_iterate(dirs, dirname) {
    DIR *dir;
    struct dirent *entry;
 
    /* Open the directory for reading. */
    dir = fc_opendir(dirname);
    if (!dir) {
      if (errno == ENOENT) {
        log_verbose("Skipping non-existing data directory %s.",
                    dirname);
      } else {
        /* TRANS: "...: <externally translated error string>."*/
        log_error(_("Could not read data directory %s: %s."),
                  dirname, fc_strerror(fc_get_errno()));
      }
      continue;
    }
 
    /* Scan all entries in the directory. */
    while ((entry = readdir(dir))) {
      size_t len = strlen(entry->d_name);
 
      /* Make sure the file name matches. */
      if (len > suffix_len
          && strcmp(suffix, entry->d_name + len - suffix_len) == 0) {
        /* Strdup the entry so we can safely write to it. */
        char *match = fc_strdup(entry->d_name);
 
        /* Clip the suffix. */
        match[len - suffix_len] = '\0';
 
        strvec_append(files, match);
        free(match);
      }
    }
 
    closedir(dir);
  } strvec_iterate_end;
 
  /* Sort the list and remove duplications. */
  strvec_remove_duplicate(files, strcmp);
  strvec_sort(files, compare_strings_strvec);
 
  return files;
}
 
/************************************************************************/
const char *fileinfoname(const struct strvec *dirs, const char *filename)
{
#ifndef DIR_SEPARATOR_IS_DEFAULT
  char fnbuf[filename != NULL ? strlen(filename) + 1 : 1];
  int i;
#else  /* DIR_SEPARATOR_IS_DEFAULT */
  const char *fnbuf = filename;
#endif /* DIR_SEPARATOR_IS_DEFAULT */
 
  if (NULL == dirs) {
    return NULL;
  }
 
  if (!filename) {
    bool first = TRUE;
 
    astr_clear(&realfile);
    strvec_iterate(dirs, dirname) {
      if (first) {
        astr_add(&realfile, "%s%s", PATH_SEPARATOR, dirname);
        first = FALSE;
      } else {
        astr_add(&realfile, "%s", dirname);
      }
    } strvec_iterate_end;
 
    return astr_str(&realfile);
  }
 
#ifndef DIR_SEPARATOR_IS_DEFAULT
  for (i = 0; filename[i] != '\0'; i++) {
    if (filename[i] == '/') {
      fnbuf[i] = DIR_SEPARATOR_CHAR;
    } else {
      fnbuf[i] = filename[i];
    }
  }
  fnbuf[i] = '\0';
#endif /* DIR_SEPARATOR_IS_DEFAULT */
 
  strvec_iterate(dirs, dirname) {
    struct stat buf;    /* see if we can open the file or directory */
 
    astr_set(&realfile, "%s" DIR_SEPARATOR "%s", dirname, fnbuf);
    if (fc_stat(astr_str(&realfile), &buf) == 0) {
      return astr_str(&realfile);
    }
  } strvec_iterate_end;
 
  log_verbose("Could not find readable file \"%s\" in data path.", filename);
 
  return NULL;
}
 
/************************************************************************/
void free_fileinfo_data(void)
{
  astr_free(&realfile);
}
 
/************************************************************************/
static void fileinfo_destroy(struct fileinfo *pfile)
{
  free(pfile->name);
  free(pfile->fullname);
  free(pfile);
}
 
/************************************************************************/
static int compare_file_mtime_ptrs(const struct fileinfo *const *ppa,
                                   const struct fileinfo *const *ppb)
{
  time_t a = (*ppa)->mtime;
  time_t b = (*ppb)->mtime;
 
  return ((a < b) ? 1 : (a > b) ? -1 : 0);
}
 
/************************************************************************/
static int compare_file_name_ptrs(const struct fileinfo *const *ppa,
                                  const struct fileinfo *const *ppb)
{
  return fc_strcoll((*ppa)->name, (*ppb)->name);
}
 
/************************************************************************/
static bool compare_fileinfo_name(const struct fileinfo *pa,
                                  const struct fileinfo *pb)
{
  return 0 == fc_strcoll(pa->name, pb->name);
}
 
/************************************************************************/
struct fileinfo_list *fileinfolist_infix(const struct strvec *dirs,
                                         const char *infix, bool nodups)
{
  struct fileinfo_list *res;
 
  if (NULL == dirs) {
    return NULL;
  }
 
  res = fileinfo_list_new_full(fileinfo_destroy);
 
  /* First assemble a full list of names. */
  strvec_iterate(dirs, dirname) {
    DIR *dir;
    struct dirent *entry;
 
    /* Open the directory for reading. */
    dir = fc_opendir(dirname);
    if (!dir) {
      continue;
    }
 
    /* Scan all entries in the directory. */
    while ((entry = readdir(dir))) {
      struct fileinfo *file;
      char *ptr;
      /* Strdup the entry so we can safely write to it. */
      char *filename = fc_strdup(entry->d_name);
 
      /* Make sure the file name matches. */
      if ((ptr = strstr(filename, infix))) {
        struct stat buf;
        char *fullname;
        size_t len = strlen(dirname) + strlen(filename) + 2;
 
        fullname = fc_malloc(len);
        fc_snprintf(fullname, len, "%s" DIR_SEPARATOR "%s", dirname, filename);
 
        if (fc_stat(fullname, &buf) == 0) {
          file = fc_malloc(sizeof(*file));
 
          /* Clip the suffix. */
          *ptr = '\0';
 
          file->name = filename;
          file->fullname = fullname;
          file->mtime = buf.st_mtime;
 
          fileinfo_list_append(res, file);
        } else {
          free(fullname);
          free(filename);
        }
      } else {
        free(filename);
      }
    }
 
    closedir(dir);
  } strvec_iterate_end;
 
  /* Sort the list by name. */
  fileinfo_list_sort(res, compare_file_name_ptrs);
 
  if (nodups) {
    fileinfo_list_unique_full(res, compare_fileinfo_name);
  }
 
  /* Sort the list by last modification time. */
  fileinfo_list_sort(res, compare_file_mtime_ptrs);
 
  return res;
}
 
/************************************************************************/
const char *setup_langname(void)
{
  const char *langname = NULL;
 
#ifdef ENABLE_NLS
  langname = getenv("LANG");
 
#ifdef FREECIV_MSWINDOWS
  /* set LANG by hand if it is not set */
  if (!langname) {
    switch (PRIMARYLANGID(GetUserDefaultLangID())) {
      case LANG_ARABIC:
        langname = "ar";
        break;
      case LANG_CATALAN:
        langname = "ca";
        break;
      case LANG_CZECH:
        langname = "cs";
        break;
      case LANG_DANISH:
        langname = "da";
        break;
      case LANG_GERMAN:
        langname = "de";
        break;
      case LANG_GREEK:
        langname = "el";
        break;
      case LANG_ENGLISH:
        switch (SUBLANGID(GetUserDefaultLangID())) {
          case SUBLANG_ENGLISH_UK:
            langname = "en_GB";
            break;
          default:
            langname = "en";
            break;
        }
        break;
      case LANG_SPANISH:
        langname = "es";
        break;
      case LANG_ESTONIAN:
        langname = "et";
        break;
      case LANG_FARSI:
        langname = "fa";
        break;
      case LANG_FINNISH:
        langname = "fi";
        break;
      case LANG_FRENCH:
        langname = "fr";
        break;
      case LANG_HEBREW:
        langname = "he";
        break;
      case LANG_HUNGARIAN:
        langname = "hu";
        break;
      case LANG_ITALIAN:
        langname = "it";
        break;
      case LANG_JAPANESE:
        langname = "ja";
        break;
      case LANG_KOREAN:
        langname = "ko";
        break;
      case LANG_LITHUANIAN:
        langname = "lt";
        break;
      case LANG_DUTCH:
        langname = "nl";
        break;
      case LANG_NORWEGIAN:
        langname = "nb";
        break;
      case LANG_POLISH:
        langname = "pl";
        break;
      case LANG_PORTUGUESE:
        switch (SUBLANGID(GetUserDefaultLangID())) {
          case SUBLANG_PORTUGUESE_BRAZILIAN:
            langname = "pt_BR";
            break;
          default:
            langname = "pt";
            break;
        }
        break;
      case LANG_ROMANIAN:
        langname = "ro";
        break;
      case LANG_RUSSIAN:
        langname = "ru";
        break;
      case LANG_SWEDISH:
        langname = "sv";
        break;
      case LANG_TURKISH:
        langname = "tr";
        break;
      case LANG_UKRAINIAN:
        langname = "uk";
        break;
      case LANG_CHINESE:
        langname = "zh_CN";
        break;
    }
 
    if (langname != NULL) {
      static char envstr[40];
 
      fc_snprintf(envstr, sizeof(envstr), "LANG=%s", langname);
      putenv(envstr);
    }
  }
#endif /* FREECIV_MSWINDOWS */
#endif /* ENABLE_NLS */
 
  return langname;
}
 
#ifdef FREECIV_ENABLE_NLS
/************************************************************************/
static void autocap_update(void)
{
  char *autocap_opt_in[] = { "fi", NULL };
  int i;
  bool ac_enabled = FALSE;
 
  char *lang = getenv("LANG");
 
  if (lang != NULL && lang[0] != '\0' && lang[1] != '\0') {
    for (i = 0; autocap_opt_in[i] != NULL && !ac_enabled; i++) {
      if (lang[0] == autocap_opt_in[i][0]
          && lang[1] == autocap_opt_in[i][1]) {
        ac_enabled = TRUE;
        break;
      }
    }
  }
 
  capitalization_opt_in(ac_enabled);
}
#endif /* FREECIV_ENABLE_NLS */
 
/************************************************************************/
void switch_lang(const char *lang)
{
#ifdef FREECIV_ENABLE_NLS
#ifdef HAVE_SETENV
  setenv("LANG", lang, TRUE);
#else  /* HAVE_SETENV */
  if (lang != NULL) {
    static char envstr[40];
 
    fc_snprintf(envstr, sizeof(envstr), "LANG=%s", lang);
    putenv(envstr);
  }
#endif /* HAVE_SETENV */
 
  (void) setlocale(LC_ALL, "");
  (void) bindtextdomain("freeciv-core", get_locale_dir());
 
  autocap_update();
 
  log_normal("LANG set to %s", lang);
#else  /* FREECIV_ENABLE_NLS */
  fc_assert(FALSE);
#endif /* FREECIV_ENABLE_NLS */
}
 
/************************************************************************/
void init_nls(void)
{
  /*
   * Setup the cached locale numeric formatting information. Defaults
   * are as appropriate for the US.
   */
  grouping = fc_strdup("\3");
  grouping_sep = fc_strdup(",");
 
#ifdef ENABLE_NLS
 
#ifdef FREECIV_MSWINDOWS
  setup_langname(); /* Makes sure LANG env variable has been set */
#endif /* FREECIV_MSWINDOWS */
 
  (void) setlocale(LC_ALL, "");
  (void) bindtextdomain("freeciv-core", get_locale_dir());
  (void) textdomain("freeciv-core");
 
  /* Don't touch the defaults when LC_NUMERIC == "C".
     This is intended to cater to the common case where:
       1) The user is from North America. ;-)
       2) The user has not set the proper environment variables.
          (Most applications are (unfortunately) US-centric
          by default, so why bother?)
     This would result in the "C" locale being used, with grouping ""
     and thousands_sep "", where we really want "\3" and ",". */
 
  if (strcmp(setlocale(LC_NUMERIC, NULL), "C") != 0) {
    struct lconv *lc = localeconv();
 
    if (lc->grouping[0] == '\0') {
      /* This actually indicates no grouping at all. */
      char *m = malloc(sizeof(char));
      *m = CHAR_MAX;
      grouping = m;
    } else {
      size_t len;
      for (len = 0;
           lc->grouping[len] != '\0' && lc->grouping[len] != CHAR_MAX; len++) {
        /* nothing */
      }
      len++;
      free(grouping);
      grouping = fc_malloc(len);
      memcpy(grouping, lc->grouping, len);
    }
    free(grouping_sep);
    grouping_sep = fc_strdup(lc->thousands_sep);
  }
 
  autocap_update();
 
#endif /* ENABLE_NLS */
}
 
/************************************************************************/
void free_nls(void)
{
  free(grouping);
  grouping = NULL;
  free(grouping_sep);
  grouping_sep = NULL;
}
 
/************************************************************************/
void dont_run_as_root(const char *argv0, const char *fallback)
{
#if (defined(ALWAYS_ROOT) || defined(__EMX__) || defined(__BEOS__))
  return;
#else
  if (getuid() == 0 || geteuid() == 0) {
    fc_fprintf(stderr,
               _("%s: Fatal error: you're trying to run me as superuser!\n"),
               (argv0 ? argv0 : fallback ? fallback : "freeciv"));
    fc_fprintf(stderr, _("Use a non-privileged account instead.\n"));
    exit(EXIT_FAILURE);
  }
#endif /* ALWAYS_ROOT */
}
 
/************************************************************************/
const char *m_pre_description(enum m_pre_result result)
{
  static const char * const descriptions[] = {
    N_("exact match"),
    N_("only match"),
    N_("ambiguous"),
    N_("empty"),
    N_("too long"),
    N_("non-match")
  };
  fc_assert_ret_val(result >= 0 && result < ARRAY_SIZE(descriptions), NULL);
  return descriptions[result];
}
 
/************************************************************************/
enum m_pre_result match_prefix(m_pre_accessor_fn_t accessor_fn,
                               size_t n_names,
                               size_t max_len_name,
                               m_pre_strncmp_fn_t cmp_fn,
                               m_strlen_fn_t len_fn,
                               const char *prefix,
                               int *ind_result)
{
  return match_prefix_full(accessor_fn, n_names, max_len_name, cmp_fn,
                           len_fn, prefix, ind_result, NULL, 0, NULL);
}
 
/************************************************************************/
enum m_pre_result match_prefix_full(m_pre_accessor_fn_t accessor_fn,
                                    size_t n_names,
                                    size_t max_len_name,
                                    m_pre_strncmp_fn_t cmp_fn,
                                    m_strlen_fn_t len_fn,
                                    const char *prefix,
                                    int *ind_result,
                                    int *matches,
                                    int max_matches,
                                    int *pnum_matches)
{
  int i, len, nmatches;
 
  if (len_fn == NULL) {
    len = strlen(prefix);
  } else {
    len = len_fn(prefix);
  }
  if (len == 0) {
    return M_PRE_EMPTY;
  }
  if (len > max_len_name && max_len_name > 0) {
    return M_PRE_LONG;
  }
 
  nmatches = 0;
  for (i = 0; i < n_names; i++) {
    const char *name = accessor_fn(i);
 
    if (cmp_fn(name, prefix, len) == 0) {
      if (strlen(name) == len) {
        *ind_result = i;
        return M_PRE_EXACT;
      }
      if (nmatches == 0) {
        *ind_result = i;        /* first match */
      }
      if (matches != NULL && nmatches < max_matches) {
        matches[nmatches] = i;
      }
      nmatches++;
    }
  }
 
  if (nmatches == 1) {
    return M_PRE_ONLY;
  } else if (nmatches > 1) {
    if (pnum_matches != NULL) {
      *pnum_matches = MIN(max_matches, nmatches);
    }
    return M_PRE_AMBIGUOUS;
  } else {
    return M_PRE_FAIL;
  }
}
 
/************************************************************************/
char *get_multicast_group(bool ipv6_preferred)
{
  static char *default_multicast_group_ipv4 = "225.1.1.1";
#ifdef FREECIV_IPV6_SUPPORT
  /* TODO: Get useful group (this is node local) */
  static char *default_multicast_group_ipv6 = "FF31::8000:15B4";
#endif /* IPv6 support */
 
  if (mc_group == NULL) {
    char *env = getenv("FREECIV_MULTICAST_GROUP");
 
    if (env) {
      mc_group = fc_strdup(env);
    } else {
#ifdef FREECIV_IPV6_SUPPORT
      if (ipv6_preferred) {
        mc_group = fc_strdup(default_multicast_group_ipv6);
      } else
#endif /* IPv6 support */
      {
        mc_group = fc_strdup(default_multicast_group_ipv4);
      }
    }
  }
 
  return mc_group;
}
 
/************************************************************************/
void free_multicast_group(void)
{
  if (mc_group != NULL) {
    free(mc_group);
    mc_group = NULL;
  }
}
 
/************************************************************************/
void interpret_tilde(char *buf, size_t buf_size, const char *filename)
{
  if (filename[0] == '~' && filename[1] == DIR_SEPARATOR_CHAR) {
    fc_snprintf(buf, buf_size, "%s" DIR_SEPARATOR "%s", user_home_dir(), filename + 2);
  } else if (filename[0] == '~' && filename[1] == '\0') {
    strncpy(buf, user_home_dir(), buf_size);
  } else  {
    strncpy(buf, filename, buf_size);
  }
}
 
/************************************************************************/
char *interpret_tilde_alloc(const char *filename)
{
  if (filename[0] == '~' && filename[1] == DIR_SEPARATOR_CHAR) {
    const char *home = user_home_dir();
    size_t sz;
    char *buf;
 
    filename += 2; /* Skip past "~/" */
    sz = strlen(home) + strlen(filename) + 2;
    buf = fc_malloc(sz);
    fc_snprintf(buf, sz, "%s/%s", home, filename);
    return buf;
  } else if (filename[0] == '~' && filename[1] == '\0') {
    return fc_strdup(user_home_dir());
  } else  {
    return fc_strdup(filename);
  }
}
 
/************************************************************************/
char *skip_to_basename(char *filepath)
{
  int j;
  fc_assert_ret_val(NULL != filepath, NULL);
 
  for (j = strlen(filepath); j >= 0; j--) {
    if (filepath[j] == DIR_SEPARATOR_CHAR) {
      return &filepath[j+1];
    }
  }
  return filepath;
}
 
/************************************************************************/
bool make_dir(const char *pathname)
{
  char *dir;
  char *path = NULL;
 
  if (pathname[0] == '\0') {
    return FALSE;
  }
 
  path = interpret_tilde_alloc(pathname);
  dir = path;
 
  if (*dir == '/') {
    /* Don't consider root as directory separator, but skip it. */
    dir++;
  } else if (dir[0] != '\0' && dir[1] == ':' && dir[2] == '\\') {
    /* Don't consider Windows Drive a directory to create, but skip it. */
    dir += 3;
  }
 
  do {
    dir = strchr(dir, DIR_SEPARATOR_CHAR);
    /* We set the current / with 0, and restore it afterwards */
    if (dir) {
      *dir = '\0';
    }
 
#ifdef FREECIV_MSWINDOWS
#ifdef HAVE__MKDIR
    /* Prefer _mkdir() in Windows even if mkdir() would seem to be available -
     * chances are that it's wrong kind of mkdir().
     * TODO: Make a configure check for mkdir() that also makes sure that it
     *       takes two parameters, and prefer such proper mkdir() here. */
    {
      char *path_in_local_encoding = internal_to_local_string_malloc(path);
      bool failure = FALSE;
 
      if (_mkdir(path_in_local_encoding) == -1
          && fc_get_errno() != ERROR_ALREADY_EXISTS) {
        failure = TRUE;
      }
 
      free(path_in_local_encoding);
 
      if (failure) {
        free(path);
        return FALSE;
      }
    }
#else  /* HAVE__MKDIR */
    if (mkdir(path, 0755) == -1
        && fc_get_errno() != EEXIST) {
      free(path);
      return FALSE;
    }
#endif /* HAVE__MKDIR */
#else  /* FREECIV_MSWINDOWS */
    if (mkdir(path, 0755) == -1
        && fc_get_errno() != EEXIST) {
      free(path);
      return FALSE;
    }
#endif /* FREECIV_MSWINDOWS */
 
    if (dir) {
      *dir = DIR_SEPARATOR_CHAR;
      dir++;
    }
  } while (dir);
 
  free(path);
 
  return TRUE;
}
 
/************************************************************************/
bool make_dir_for_file(char *filename)
{
  int i;
 
  for (i = strlen(filename) - 1 ; filename[i] != DIR_SEPARATOR_CHAR ; i--) {
    /* Nothing */
  }
 
  filename[i] = '\0';
  log_debug("Create directory \"%s\"", filename);
 
  if (!make_dir(filename)) {
    return FALSE;
  }
  filename[i] = DIR_SEPARATOR_CHAR;
 
  return TRUE;
}
 
/************************************************************************/
bool path_is_absolute(const char *filename)
{
  if (!filename) {
    return FALSE;
  }
 
#ifdef FREECIV_MSWINDOWS
  if (strchr(filename, ':')) {
    return TRUE;
  }
#else  /* FREECIV_MSWINDOWS */
  if (filename[0] == '/') {
    return TRUE;
  }
#endif /* FREECIV_MSWINDOWS */
 
  return FALSE;
}
 
/************************************************************************/
char scanin(const char **buf, char *delimiters, char *dest, int size)
{
  char *ptr, found = '?';
 
  if (*buf == NULL || strlen(*buf) == 0 || size == 0) {
    if (dest) {
      dest[0] = '\0';
    }
    *buf = NULL;
    return '\0';
  }
 
  if (dest) {
    strncpy(dest, *buf, size-1);
    dest[size-1] = '\0';
    remove_leading_trailing_spaces(dest);
    ptr = strpbrk(dest, delimiters);
  } else {
    /* Just skip ahead. */
    ptr = strpbrk(*buf, delimiters);
  }
  if (ptr != NULL) {
    found = *ptr;
    if (dest) {
      *ptr = '\0';
    }
    if (dest) {
      remove_leading_trailing_spaces(dest);
    }
    *buf = strpbrk(*buf, delimiters);
    if (*buf != NULL) {
      (*buf)++; /* skip delimiter */
    } else {
    }
  } else {
    *buf = NULL;
  }
 
  return found;
}
 
/************************************************************************/
void format_time_duration(time_t t, char *buf, int maxlen)
{
  int seconds, minutes, hours, days;
  bool space = FALSE;
 
  seconds = t % 60;
  minutes = (t / 60) % 60;
  hours = (t / (60 * 60)) % 24;
  days = t / (60 * 60 * 24);
 
  if (maxlen <= 0) {
    return;
  }
 
  buf[0] = '\0';
 
  if (days > 0) {
    cat_snprintf(buf, maxlen, "%d %s", days, PL_("day", "days", days));
    space = TRUE;
  }
  if (hours > 0) {
    cat_snprintf(buf, maxlen, "%s%d %s",
                 space ? " " : "", hours, PL_("hour", "hours", hours));
    space = TRUE;
  }
  if (minutes > 0) {
    cat_snprintf(buf, maxlen, "%s%d %s",
                 space ? " " : "",
                 minutes, PL_("minute", "minutes", minutes));
    space = TRUE;
  }
  if (seconds > 0) {
    cat_snprintf(buf, maxlen, "%s%d %s",
                 space ? " " : "",
                 seconds, PL_("second", "seconds", seconds));
  }
}
 
/************************************************************************/
void array_shuffle(int *array, int n)
{
  if (n > 1 && array != NULL) {
    int i, j, t;
    for (i = 0; i < n - 1; i++) {
      j = i + fc_rand(n - i);
      t = array[j];
      array[j] = array[i];
      array[i] = t;
    }
  }
}
 
/************************************************************************/
static bool wildcard_asterisk_fit(const char *pattern, const char *test)
{
  char jump_to;
 
  /* Jump over the leading asterisks. */
  pattern++;
  while (TRUE) {
    switch (*pattern) {
    case '\0':
      /* It is a leading asterisk. */
      return TRUE;
    case '*':
      pattern++;
      continue;
    case '?':
      if ('\0' == *test) {
        return FALSE;
      }
      test++;
      pattern++;
      continue;
    }
 
    break;
  }
 
  if ('[' != *pattern) {
    if ('\\' == *pattern) {
      jump_to = *(pattern + 1);
    } else {
      jump_to = *pattern;
    }
  } else {
    jump_to = '\0';
  }
 
  while ('\0' != *test) {
    if ('\0' != jump_to) {
      /* Jump to next matching charather. */
      test = strchr(test, jump_to);
      if (NULL == test) {
        /* No match. */
        return FALSE;
      }
    }
 
    if (wildcard_fit_string(pattern, test)) {
      return TRUE;
    }
 
    (test)++;
  }
 
  return FALSE;
}
 
/************************************************************************/
static bool wildcard_range_fit(const char **pattern, const char **test)
{
  const char *start = (*pattern + 1);
  char testc;
  bool negation;
 
  if ('\0' == **test) {
    /* Need one character. */
    return FALSE;
  }
 
  /* Find the end of the pattern. */
  while (TRUE) {
    *pattern = strchr(*pattern, ']');
    if (NULL == *pattern) {
      /* Wildcard format error. */
      return FALSE;
    } else if (*(*pattern - 1) != '\\') {
      /* This is the end. */
      break;
    } else {
      /* Try again. */
      (*pattern)++;
    }
  }
 
  if ('!' == *start) {
    negation = TRUE;
    start++;
  } else {
    negation = FALSE;
  }
  testc = **test;
  (*test)++;
  (*pattern)++;
 
  for (; start < *pattern; start++) {
    if ('-' == *start || '!' == *start) {
      /* Wildcard format error. */
      return FALSE;
    } else if (start < *pattern - 2 && '-' == *(start + 1)) {
      /* Case range. */
      if (*start <= testc && testc <= *(start + 2)) {
        return !negation;
      }
      start += 2;
    } else if (*start == testc) {
      /* Single character. */
      return !negation;
    }
  }
 
  return negation;
}
 
/************************************************************************/
bool wildcard_fit_string(const char *pattern, const char *test)
{
  while (TRUE) {
    switch (*pattern) {
    case '\0':
      /* '\0' != test. */
      return '\0' == *test;
    case '*':
      return wildcard_asterisk_fit(pattern, test); /* Maybe recursive. */
    case '[':
      if (!wildcard_range_fit(&pattern, &test)) {
        return FALSE;
      }
      continue;
    case '?':
      if ('\0' == *test) {
        return FALSE;
      }
      break;
    case '\\':
      pattern++;
      fc__fallthrough; /* No break */
    default:
      if (*pattern != *test) {
        return FALSE;
      }
      break;
    }
    pattern++;
    test++;
  }
 
  return FALSE;
}
 
/************************************************************************/
int fc_vsnprintcf(char *buf, size_t buf_len, const char *format,
                  const struct cf_sequence *sequences, size_t sequences_num)
{
  const struct cf_sequence *pseq;
  char cformat[32];
  const char *f = format;
  char *const max = buf + buf_len - 1;
  char *b = buf, *c;
  const char *const cmax = cformat + sizeof(cformat) - 2;
  int i, j;
 
  if ((size_t) -1 == sequences_num) {
    /* Find the number of sequences. */
    sequences_num = 0;
    for (pseq = sequences; CF_LAST != pseq->type; pseq++) {
      sequences_num++;
    }
  }
 
  while ('\0' != *f) {
    if ('%' == *f) {
      /* Sequence. */
 
      f++;
      if ('%' == *f) {
        /* Double '%'. */
        *b++ = '%';
        f++;
        continue;
      }
 
      /* Make format. */
      c = cformat;
      *c++ = '%';
      for (; !fc_isalpha(*f) && '\0' != *f && '%' != *f && cmax > c; f++) {
        *c++ = *f;
      }
 
      if (!fc_isalpha(*f)) {
        /* Beginning of a new sequence, end of the format, or too long
         * sequence. */
        *c = '\0';
        j = fc_snprintf(b, max - b + 1, "%s", cformat);
        if (-1 == j) {
          return -1;
        }
        b += j;
        continue;
      }
 
      for (i = 0, pseq = sequences; i < sequences_num; i++, pseq++) {
        if (pseq->letter == *f) {
          j = -2;
          switch (pseq->type) {
          case CF_BOOLEAN:
            *c++ = 's';
            *c = '\0';
            j = fc_snprintf(b, max - b + 1, cformat,
                            pseq->bool_value ? "TRUE" : "FALSE");
            break;
          case CF_TRANS_BOOLEAN:
            *c++ = 's';
            *c = '\0';
            j = fc_snprintf(b, max - b + 1, cformat,
                            pseq->bool_value ? _("TRUE") : _("FALSE"));
            break;
          case CF_CHARACTER:
            *c++ = 'c';
            *c = '\0';
            j = fc_snprintf(b, max - b + 1, cformat, pseq->char_value);
            break;
          case CF_INTEGER:
            *c++ = 'd';
            *c = '\0';
            j = fc_snprintf(b, max - b + 1, cformat, pseq->int_value);
            break;
          case CF_HEXA:
            *c++ = 'x';
            *c = '\0';
            j = fc_snprintf(b, max - b + 1, cformat, pseq->int_value);
            break;
          case CF_FLOAT:
            *c++ = 'f';
            *c = '\0';
            j = fc_snprintf(b, max - b + 1, cformat, pseq->float_value);
            break;
          case CF_POINTER:
            *c++ = 'p';
            *c = '\0';
            j = fc_snprintf(b, max - b + 1, cformat, pseq->ptr_value);
            break;
          case CF_STRING:
            *c++ = 's';
            *c = '\0';
            j = fc_snprintf(b, max - b + 1, cformat, pseq->str_value);
            break;
          case CF_LAST:
            break;
          };
          if (-2 == j) {
            log_error("Error: unsupported sequence type: %d.", pseq->type);
            break;
          }
          if (-1 == j) {
            /* Full! */
            return -1;
          }
          f++;
          b += j;
          break;
        }
      }
      if (i >= sequences_num) {
        /* Format not supported. */
        *c = '\0';
        j = fc_snprintf(b, max - b + 1, "%s%c", cformat, *f);
        if (-1 == j) {
          return -1;
        }
        f++;
        b += j;
      }
    } else {
      /* Not a sequence. */
      *b++ = *f++;
    }
    if (max <= b) {
      /* Too long. */
      *max = '\0';
      return -1;
    }
  }
  *b = '\0';
  return b - buf;
}
 
/************************************************************************/
int fc_snprintcf(char *buf, size_t buf_len, const char *format, ...)
{
  struct cf_sequence sequences[16];
  size_t sequences_num = 0;
  va_list args;
 
  /* Collect sequence array. */
  va_start(args, format);
  do {
    sequences[sequences_num] = va_arg(args, struct cf_sequence);
    if (CF_LAST == sequences[sequences_num].type) {
      break;
    } else {
      sequences_num++;
    }
  } while (ARRAY_SIZE(sequences) > sequences_num);
 
  if (ARRAY_SIZE(sequences) <= sequences_num
      && CF_LAST != va_arg(args, struct cf_sequence).type) {
    log_error("Too many custom sequences. Maybe did you forget cf_end() "
              "at the end of the arguments?");
    buf[0] = '\0';
    va_end(args);
    return -1;
  }
  va_end(args);
 
  return fc_vsnprintcf(buf, buf_len, format, sequences, sequences_num);
}
 
/************************************************************************/
static size_t extract_escapes(const char *format, char *escapes,
                              size_t max_escapes)
{
  static const char format_escapes[] = {
    '*', 'd', 'i', 'o', 'u', 'x', 'X', 'e', 'E', 'f',
    'F', 'g', 'G', 'a', 'A', 'c', 's', 'p', 'n', '\0'
  };
  bool reordered = FALSE;
  size_t num = 0;
  int idx = 0;
 
  memset(escapes, 0, max_escapes);
  format = strchr(format, '%');
  while (NULL != format) {
    format++;
    if ('%' == *format) {
      /* Double, not a sequence. */
      continue;
    } else if (fc_isdigit(*format)) {
      const char *start = format;
 
      do {
        format++;
      } while (fc_isdigit(*format));
      if ('$' == *format) {
        /* Strings are reordered. */
        sscanf(start, "%d", &idx);
        reordered = TRUE;
      }
    }
 
    while ('\0' != *format
           && NULL == strchr(format_escapes, *format)) {
      format++;
    }
    escapes[idx] = *format;
 
    /* Increase the read count. */
    if (reordered) {
      if (idx > num) {
        num = idx;
      }
    } else {
      idx++;
      num++;
    }
 
    if ('*' != *format) {
      format = strchr(format, '%');
    } /* else we didn't have found the real sequence. */
  }
  return num;
}
 
/************************************************************************/
bool formats_match(const char *format1, const char *format2)
{
  char format1_escapes[256], format2_escapes[256];
  size_t format1_escapes_num = extract_escapes(format1, format1_escapes,
                                               sizeof(format1_escapes));
  size_t format2_escapes_num = extract_escapes(format2, format2_escapes,
                                               sizeof(format2_escapes));
 
  return (format1_escapes_num == format2_escapes_num
          && 0 == memcmp(format1_escapes, format2_escapes,
                         format1_escapes_num));
}