path: root/src/utils.c

/*
 * Calcurse - text-based organizer
 *
 * Copyright (c) 2004-2013 calcurse Development Team <misc@calcurse.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the
 *        following disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the
 *        following disclaimer in the documentation and/or other
 *        materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Send your feedback or comments to : misc@calcurse.org
 * Calcurse home page : http://calcurse.org
 *
 */

#include <time.h>
#include <string.h>
#include <stdlib.h>
#include <limits.h>
#include <unistd.h>
#include <ctype.h>
#include <sys/types.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/wait.h>
#include <termios.h>

#include "calcurse.h"

#define ISLEAP(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)

#define FS_EXT_MAXLEN 64

enum format_specifier {
  FS_STARTDATE,
  FS_DURATION,
  FS_ENDDATE,
  FS_MESSAGE,
  FS_NOTE,
  FS_NOTEFILE,
  FS_PRIORITY,
  FS_PSIGN,
  FS_EOF,
  FS_UNKNOWN
};

/* General routine to exit calcurse properly. */
void exit_calcurse(int status)
{
  int was_interactive;

  if (ui_mode == UI_CURSES) {
    notify_stop_main_thread();
    clear();
    wins_refresh();
    endwin();
    ui_mode = UI_CMDLINE;
    was_interactive = 1;
  } else
    was_interactive = 0;

  ui_calendar_stop_date_thread();
  io_stop_psave_thread();
  free_user_data();
  keys_free();
  mem_stats();
  if (was_interactive) {
    if (unlink(path_cpid) != 0)
      EXIT(_("Could not remove calcurse lock file: %s\n"), strerror(errno));
    if (dmon.enable)
      dmon_start(status);
  }

  exit(status);
}

void free_user_data(void)
{
  unsigned i;

  day_free_list();
  event_llist_free();
  apoint_llist_free();
  recur_apoint_llist_free();
  recur_event_llist_free();
  for (i = 0; i <= 37; i++)
    ui_day_item_cut_free(i);
  todo_free_list();
  notify_free_app();
}

/* Function to exit on internal error. */
void fatalbox(const char *errmsg)
{
  WINDOW *errwin;
  const char *label = _("/!\\ INTERNAL ERROR /!\\");
  const char *reportmsg = _("Please report the following bug:");
  const int WINROW = 10;
  const int WINCOL = col - 2;
  const int MSGLEN = WINCOL - 2;
  char msg[MSGLEN];

  if (errmsg == NULL)
    return;

  strncpy(msg, errmsg, MSGLEN);
  errwin = newwin(WINROW, WINCOL, (row - WINROW) / 2, (col - WINCOL) / 2);
  custom_apply_attr(errwin, ATTR_HIGHEST);
  box(errwin, 0, 0);
  wins_show(errwin, label);
  mvwaddstr(errwin, 3, 1, reportmsg);
  mvwaddstr(errwin, 5, (WINCOL - strlen(msg)) / 2, msg);
  custom_remove_attr(errwin, ATTR_HIGHEST);
  wins_wrefresh(errwin);
  wgetch(errwin);
  delwin(errwin);
  wins_doupdate();
}

void warnbox(const char *msg)
{
  WINDOW *warnwin;
  const char *label = "/!\\";
  const int WINROW = 10;
  const int WINCOL = col - 2;
  const int MSGLEN = WINCOL - 2;
  char displmsg[MSGLEN];

  if (msg == NULL)
    return;

  strncpy(displmsg, msg, MSGLEN);
  warnwin = newwin(WINROW, WINCOL, (row - WINROW) / 2, (col - WINCOL) / 2);
  custom_apply_attr(warnwin, ATTR_HIGHEST);
  box(warnwin, 0, 0);
  wins_show(warnwin, label);
  mvwaddstr(warnwin, 5, (WINCOL - strlen(displmsg)) / 2, displmsg);
  custom_remove_attr(warnwin, ATTR_HIGHEST);
  wins_wrefresh(warnwin);
  wgetch(warnwin);
  delwin(warnwin);
  wins_doupdate();
}

/*
 * Print a message in the status bar.
 * Message texts for first line and second line are to be provided.
 */
void status_mesg(const char *msg1, const char *msg2)
{
  wins_erase_status_bar();
  custom_apply_attr(win[STA].p, ATTR_HIGHEST);
  mvwaddstr(win[STA].p, 0, 0, msg1);
  mvwaddstr(win[STA].p, 1, 0, msg2);
  custom_remove_attr(win[STA].p, ATTR_HIGHEST);
  wins_wrefresh(win[STA].p);
}

/*
 * Prompts the user to make a choice between named alternatives.
 *
 * The available choices are described by a string of the form
 * "[ynp]". The first and last char are ignored (they are only here to
 * make the translators' life easier), and every other char indicates
 * a key the user is allowed to press.
 *
 * Returns the index of the key pressed by the user (starting from 1),
 * or -1 if the user doesn't want to answer (e.g. by escaping).
 */
int status_ask_choice(const char *message, const char choice[], int nb_choice)
{
  int i, ch;
  char tmp[BUFSIZ];
  /* "[4/2/f/t/w/.../Z] " */
  char avail_choice[2 * nb_choice + 3];

  avail_choice[0] = '[';
  avail_choice[1] = '\0';

  for (i = 1; i <= nb_choice; i++) {
    snprintf(tmp, BUFSIZ, (i == nb_choice) ? "%c] " : "%c/", choice[i]);
    strcat(avail_choice, tmp);
  }

  status_mesg(message, avail_choice);

  for (;;) {
    ch = wgetch(win[KEY].p);
    for (i = 1; i <= nb_choice; i++)
      if (ch == choice[i])
        return i;
    if (ch == ESCAPE)
      return (-1);
    if (resize) {
      resize = 0;
      wins_reset();
      status_mesg(message, avail_choice);
    }
  }
}

/*
 * Prompts the user with a boolean question.
 *
 * Returns 1 if yes, 2 if no, and -1 otherwise
 */
int status_ask_bool(const char *msg)
{
  return (status_ask_choice(msg, _("[yn]"), 2));
}

/*
 * Prompts the user to make a choice between a number of alternatives.
 *
 * Returns the option chosen by the user (starting from 1), or -1 if
 * the user doesn't want to answer.
 */
int
status_ask_simplechoice(const char *prefix, const char *choice[], int nb_choice)
{
  int i;
  char tmp[BUFSIZ];
  /* "(1) Choice1, (2) Choice2, (3) Choice3?" */
  char choicestr[BUFSIZ];
  /* Holds the characters to choose from ('1', '2', etc) */
  char char_choice[nb_choice + 2];

  /* No need to initialize first and last char. */
  for (i = 1; i <= nb_choice; i++)
    char_choice[i] = '0' + i;

  strcpy(choicestr, prefix);

  for (i = 0; i < nb_choice; i++) {
    snprintf(tmp, BUFSIZ, ((i + 1) == nb_choice) ? "(%d) %s?" : "(%d) %s, ",
             (i + 1), choice[i]);
    strcat(choicestr, tmp);
  }

  return (status_ask_choice(choicestr, char_choice, nb_choice));
}

/* Erase part of a window. */
void
erase_window_part(WINDOW * win, int first_col, int first_row, int last_col,
                  int last_row)
{
  int c, r;

  for (r = first_row; r <= last_row; r++) {
    for (c = first_col; c <= last_col; c++)
      mvwaddstr(win, r, c, " ");
  }
}

/* draws a popup window */
WINDOW *popup(int pop_row, int pop_col, int pop_y, int pop_x, const char *title,
              const char *msg, int hint)
{
  const char *any_key = _("Press any key to continue...");
  WINDOW *popup_win;
  const int MSGXPOS = 5;

  popup_win = newwin(pop_row, pop_col, pop_y, pop_x);
  keypad(popup_win, TRUE);
  if (msg)
    mvwaddstr(popup_win, MSGXPOS, (pop_col - strlen(msg)) / 2, msg);
  custom_apply_attr(popup_win, ATTR_HIGHEST);
  box(popup_win, 0, 0);
  wins_show(popup_win, title);
  if (hint)
    mvwaddstr(popup_win, pop_row - 2, pop_col - (strlen(any_key) + 1), any_key);
  custom_remove_attr(popup_win, ATTR_HIGHEST);
  wins_wrefresh(popup_win);

  return popup_win;
}

/* prints in middle of a panel */
void
print_in_middle(WINDOW * win, int starty, int startx, int width,
                const char *string)
{
  int len = strlen(string);
  int x, y;

  win = win ? win : stdscr;
  getyx(win, y, x);
  x = startx ? startx : x;
  y = starty ? starty : y;
  width = width ? width : 80;

  x += (width - len) / 2;

  custom_apply_attr(win, ATTR_HIGHEST);
  mvwaddstr(win, y, x, string);
  custom_remove_attr(win, ATTR_HIGHEST);
}

/* checks if a string is only made of digits */
int is_all_digit(const char *string)
{
  for (; *string; string++) {
    if (!isdigit((int)*string))
      return 0;
  }

  return 1;
}

/* Given an item date expressed in seconds, return its start time in seconds. */
long get_item_time(long date)
{
  return (long)(get_item_hour(date) * HOURINSEC +
                get_item_min(date) * MININSEC);
}

int get_item_hour(long date)
{
  struct tm lt;

  localtime_r((time_t *)&date, &lt);
  return lt.tm_hour;
}

int get_item_min(long date)
{
  struct tm lt;

  localtime_r((time_t *)&date, &lt);
  return lt.tm_min;
}

long date2sec(struct date day, unsigned hour, unsigned min)
{
  time_t t = now();
  struct tm start;

  localtime_r(&t, &start);

  start.tm_mon = day.mm - 1;
  start.tm_mday = day.dd;
  start.tm_year = day.yyyy - 1900;
  start.tm_hour = hour;
  start.tm_min = min;
  start.tm_sec = 0;
  start.tm_isdst = -1;

  t = mktime(&start);
  EXIT_IF(t == -1, _("failure in mktime"));

  return t;
}

/* Return a string containing the date, given a date in seconds. */
char *date_sec2date_str(long sec, const char *datefmt)
{
  struct tm lt;
  char *datestr = (char *)mem_calloc(BUFSIZ, sizeof(char));

  if (sec == 0)
    strncpy(datestr, "0", BUFSIZ);
  else {
    localtime_r((time_t *)&sec, &lt);
    strftime(datestr, BUFSIZ, datefmt, &lt);
  }

  return datestr;
}

/* Generic function to format date. */
void date_sec2date_fmt(long sec, const char *fmt, char *datef)
{
#if ENABLE_NLS
  /* TODO: Find a better way to deal with localization and strftime(). */
  char *locale_old = mem_strdup (setlocale (LC_ALL, NULL));
  setlocale (LC_ALL, "C");
#endif

  struct tm lt;
  localtime_r((time_t *)&sec, &lt);
  strftime(datef, BUFSIZ, fmt, &lt);

#if ENABLE_NLS
  setlocale (LC_ALL, locale_old);
  mem_free (locale_old);
#endif
}

/*
 * Used to change date by adding a certain amount of days or weeks.
 */
long date_sec_change(long date, int delta_month, int delta_day)
{
  struct tm lt;
  time_t t;

  t = date;
  localtime_r(&t, &lt);
  lt.tm_mon += delta_month;
  lt.tm_mday += delta_day;
  lt.tm_isdst = -1;
  t = mktime(&lt);
  EXIT_IF(t == -1, _("failure in mktime"));

  return t;
}

/*
 * Return a long containing the date which is updated taking into account
 * the new time and date entered by the user.
 */
long update_time_in_date(long date, unsigned hr, unsigned mn)
{
  struct tm lt;
  time_t t, new_date;

  t = date;
  localtime_r(&t, &lt);
  lt.tm_hour = hr;
  lt.tm_min = mn;
  new_date = mktime(&lt);
  EXIT_IF(new_date == -1, _("error in mktime"));

  return new_date;
}

/*
 * Returns the date in seconds from year 1900.
 * If no date is entered, current date is chosen.
 */
long get_sec_date(struct date date)
{
  struct tm ptrtime;
  time_t timer;
  long long_date;
  char current_day[] = "dd ";
  char current_month[] = "mm ";
  char current_year[] = "yyyy ";

  if (date.yyyy == 0 && date.mm == 0 && date.dd == 0) {
    timer = time(NULL);
    localtime_r(&timer, &ptrtime);
    strftime(current_day, strlen(current_day), "%d", &ptrtime);
    strftime(current_month, strlen(current_month), "%m", &ptrtime);
    strftime(current_year, strlen(current_year), "%Y", &ptrtime);
    date.mm = atoi(current_month);
    date.dd = atoi(current_day);
    date.yyyy = atoi(current_year);
  }
  long_date = date2sec(date, 0, 0);
  return long_date;
}

long min2sec(unsigned minutes)
{
  return minutes * MININSEC;
}

/*
 * Display a scroll bar when there are so many items that they
 * can not be displayed inside the corresponding panel.
 */
void
draw_scrollbar(WINDOW * win, int y, int x, int length,
               int bar_top, int bar_bottom, unsigned hilt)
{
  mvwvline(win, bar_top, x, ACS_VLINE, bar_bottom - bar_top);
  if (hilt)
    custom_apply_attr(win, ATTR_HIGHEST);
  wattron(win, A_REVERSE);
  mvwvline(win, y, x, ' ', length);
  wattroff(win, A_REVERSE);
  if (hilt)
    custom_remove_attr(win, ATTR_HIGHEST);
}

/*
 * Print an item (either an appointment, event, or todo) in a
 * popup window. This is useful if an item description is too
 * long to fit in its corresponding panel window.
 */
void
item_in_popup(const char *a_start, const char *a_end, const char *msg,
              const char *pop_title)
{
  WINDOW *popup_win, *pad;
  const int margin_left = 4, margin_top = 4;
  const int winl = row - 5, winw = col - margin_left;
  const int padl = winl - 2, padw = winw - margin_left;

  pad = newpad(padl, padw);
  popup_win = popup(winl, winw, 1, 2, pop_title, NULL, 1);
  if (a_start && a_end) {
    mvwprintw(popup_win, margin_top, margin_left, "- %s -> %s", a_start,
              a_end);
  }
  mvwaddstr(pad, 0, margin_left, msg);
  wmove(win[STA].p, 0, 0);
  pnoutrefresh(pad, 0, 0, margin_top + 2, margin_left, padl, winw);
  wins_doupdate();
  wgetch(popup_win);
  delwin(pad);
  delwin(popup_win);
}

/* Returns the beginning of current day in seconds from 1900. */
long get_today(void)
{
  struct tm lt;
  time_t current_time;
  long current_day;
  struct date day;

  current_time = time(NULL);
  localtime_r(&current_time, &lt);
  day.mm = lt.tm_mon + 1;
  day.dd = lt.tm_mday;
  day.yyyy = lt.tm_year + 1900;
  current_day = date2sec(day, 0, 0);

  return current_day;
}

/* Returns the current time in seconds. */
long now(void)
{
  return (long)time(NULL);
}

char *nowstr(void)
{
  struct tm lt;
  static char buf[BUFSIZ];
  time_t t = now();

  localtime_r(&t, &lt);
  strftime(buf, sizeof buf, "%a %b %d %T %Y", &lt);

  return buf;
}

/* Print the given option value with appropriate color. */
void
print_bool_option_incolor(WINDOW * win, unsigned option, int pos_y, int pos_x)
{
  int color = 0;
  const char *option_value;

  if (option == 1) {
    color = ATTR_TRUE;
    option_value = _("yes");
  } else if (option == 0) {
    color = ATTR_FALSE;
    option_value = _("no");
  } else
    EXIT(_("option not defined"));

  custom_apply_attr(win, color);
  mvwaddstr(win, pos_y, pos_x, option_value);
  custom_remove_attr(win, color);
  wnoutrefresh(win);
  wins_doupdate();
}

/*
 * Get the name of the default directory for temporary files.
 */
const char *get_tempdir(void)
{
  if (getenv("TMPDIR"))
    return getenv("TMPDIR");
#ifdef P_tmpdir
  else if (P_tmpdir)
    return P_tmpdir;
#endif
  else
    return "/tmp";
}

/*
 * Create a new unique file, and return a newly allocated string which contains
 * the random part of the file name.
 */
char *new_tempfile(const char *prefix, int trailing_len)
{
  char fullname[BUFSIZ];
  int prefix_len, fd;
  FILE *file;

  if (prefix == NULL)
    return NULL;

  prefix_len = strlen(prefix);
  if (prefix_len + trailing_len >= BUFSIZ)
    return NULL;
  memcpy(fullname, prefix, prefix_len);
  memset(fullname + prefix_len, 'X', trailing_len);
  fullname[prefix_len + trailing_len] = '\0';
  if ((fd = mkstemp(fullname)) == -1 || (file = fdopen(fd, "w+")) == NULL) {
    if (fd != -1) {
      unlink(fullname);
      close(fd);
    }
    ERROR_MSG(_("temporary file \"%s\" could not be created"), fullname);
    return NULL;
  }
  fclose(file);

  return mem_strdup(fullname + prefix_len);
}

/*
 * Convert a string containing a date into three integers containing the year,
 * month and day.
 *
 * If a pointer to a date structure containing the current date is passed as
 * last parameter ("slctd_date"), the function will accept several short forms,
 * e.g. "26" for the 26th of the current month/year or "3/1" for Mar 01 (or Jan
 * 03, depending on the date format) of the current year. If a null pointer is
 * passed, short forms won't be accepted at all.
 *
 * Returns 1 if sucessfully converted or 0 if the string is an invalid date.
 */
int
parse_date(const char *date_string, enum datefmt datefmt, int *year,
           int *month, int *day, struct date *slctd_date)
{
  const char sep = (datefmt == DATEFMT_ISO) ? '-' : '/';
  const char *p;
  int in[3] = { 0, 0, 0 }, n = 0;
  int d, m, y;

  if (!date_string)
    return 0;

  /* parse string into in[], read up to three integers */
  for (p = date_string; *p; p++) {
    if (*p == sep) {
      if ((++n) > 2)
        return 0;
    } else if ((*p >= '0') && (*p <= '9'))
      in[n] = in[n] * 10 + (int)(*p - '0');
    else
      return 0;
  }

  if ((!slctd_date && n < 2) || in[n] == 0)
    return 0;

  /* convert into day, month and year, depending on the date format */
  switch (datefmt) {
  case DATEFMT_MMDDYYYY:
    m = (n >= 1) ? in[0] : 0;
    d = (n >= 1) ? in[1] : in[0];
    y = in[2];
    break;
  case DATEFMT_DDMMYYYY:
    d = in[0];
    m = in[1];
    y = in[2];
    break;
  case DATEFMT_YYYYMMDD:
  case DATEFMT_ISO:
    y = (n >= 2) ? in[n - 2] : 0;
    m = (n >= 1) ? in[n - 1] : 0;
    d = in[n];
    break;
  default:
    return 0;
  }

  if (slctd_date) {
    if (y > 0 && y < 100) {
      /* convert "YY" format into "YYYY" */
      y += slctd_date->yyyy - slctd_date->yyyy % 100;
    } else if (n < 2) {
      /* set year and, optionally, month if short from is used */
      y = slctd_date->yyyy;
      if (n < 1)
        m = slctd_date->mm;
    }
  }

  /* check if date is valid, take leap years into account */
  if (y < 1902 || y > 2037 || m < 1 || m > 12 || d < 1 ||
      d > days[m - 1] + (m == 2 && ISLEAP(y)) ? 1 : 0)
    return 0;

  if (year)
    *year = y;
  if (month)
    *month = m;
  if (day)
    *day = d;

  return 1;
}

/*
 * Converts a time string into hours and minutes. Short forms like "23:"
 * (23:00) or ":45" (0:45) are allowed.
 *
 * Returns 1 on success and 0 on failure.
 */
int parse_time(const char *string, unsigned *hour, unsigned *minute)
{
  const char *p;
  unsigned in[2] = { 0, 0 }, n = 0;

  if (!string)
    return 0;

  /* parse string into in[], read up to two integers */
  for (p = string; *p; p++) {
    if (*p == ':') {
      if ((++n) > 1)
        return 0;
    } else if ((*p >= '0') && (*p <= '9')) {
      if ((n == 0) && (p == (string + 2)) && *(p + 1))
        n++;
      in[n] = in[n] * 10 + (int)(*p - '0');
    } else
      return 0;
  }

  if (n != 1 || in[0] >= DAYINHOURS || in[1] >= HOURINMIN)
    return 0;

  *hour = in[0];
  *minute = in[1];
  return 1;
}

/*
 * Converts a duration string into minutes.
 *
 * Allowed formats (noted as regular expressions):
 *
 * - \d*:\d*
 * - (\d*m|\d*h(|\d*m)|\d*d(|\d*m|\d*h(|\d*m)))
 * - \d+
 *
 * "\d" is used as a placeholder for "(0|1|2|3|4|5|6|7|8|9)".
 *
 * Returns 1 on success and 0 on failure.
 */
int parse_duration(const char *string, unsigned *duration)
{
  enum {
    STATE_INITIAL,
    STATE_HHMM_MM,
    STATE_DDHHMM_HH,
    STATE_DDHHMM_MM,
    STATE_DONE
  } state = STATE_INITIAL;

  const char *p;
  unsigned in = 0;
  unsigned dur = 0;

  if (!string || *string == '\0')
    return 0;

  /* parse string using a simple state machine */
  for (p = string; *p; p++) {
    if ((*p >= '0') && (*p <= '9')) {
      if (state == STATE_DONE)
        return 0;
      else
        in = in * 10 + (int)(*p - '0');
    } else {
      switch (state) {
      case STATE_INITIAL:
        if (*p == ':') {
          dur += in * HOURINMIN;
          state = STATE_HHMM_MM;
        } else if (*p == 'd') {
          dur += in * DAYINMIN;
          state = STATE_DDHHMM_HH;
        } else if (*p == 'h') {
          dur += in * HOURINMIN;
          state = STATE_DDHHMM_MM;
        } else if (*p == 'm') {
          dur += in;
          state = STATE_DONE;
        } else
          return 0;
        break;
      case STATE_DDHHMM_HH:
        if (*p == 'h') {
          dur += in * HOURINMIN;
          state = STATE_DDHHMM_MM;
        } else if (*p == 'm') {
          dur += in;
          state = STATE_DONE;
        } else
          return 0;
        break;
      case STATE_DDHHMM_MM:
        if (*p == 'm') {
          dur += in;
          state = STATE_DONE;
        } else
          return 0;
        break;
      case STATE_HHMM_MM:
      case STATE_DONE:
        return 0;
        break;
      }

      in = 0;
    }
  }

  if ((state == STATE_HHMM_MM && in >= HOURINMIN) ||
      ((state == STATE_DDHHMM_HH || state == STATE_DDHHMM_MM) && in > 0))
    return 0;

  dur += in;
  *duration = dur;

  return 1;
}

void file_close(FILE * f, const char *pos)
{
  EXIT_IF((fclose(f)) != 0, _("Error when closing file at %s"), pos);
}

/*
 * Sleep the given number of seconds, but make it more 'precise' than sleep(3)
 * (hence the 'p') in a way that even if a signal is caught during the sleep
 * process, this function will return to sleep afterwards.
 */
void psleep(unsigned secs)
{
  unsigned unslept;

  for (unslept = sleep(secs); unslept; unslept = sleep(unslept)) ;
}

/*
 * Fork and execute an external process.
 *
 * If pfdin and/or pfdout point to a valid address, a pipe is created and the
 * appropriate file descriptors are written to pfdin/pfdout.
 */
int fork_exec(int *pfdin, int *pfdout, const char *path, const char *const *arg)
{
  int pin[2], pout[2];
  int pid;

  if (pfdin && (pipe(pin) == -1))
    return 0;
  if (pfdout && (pipe(pout) == -1))
    return 0;

  if ((pid = fork()) == 0) {
    if (pfdout) {
      if (dup2(pout[0], STDIN_FILENO) < 0)
        _exit(127);
      close(pout[0]);
      close(pout[1]);
    }

    if (pfdin) {
      if (dup2(pin[1], STDOUT_FILENO) < 0)
        _exit(127);
      close(pin[0]);
      close(pin[1]);
    }

    execvp(path, (char *const *)arg);
    _exit(127);
  } else {
    if (pfdin)
      close(pin[1]);
    if (pfdout)
      close(pout[0]);

    if (pid > 0) {
      if (pfdin) {
        fcntl(pin[0], F_SETFD, FD_CLOEXEC);
        *pfdin = pin[0];
      }
      if (pfdout) {
        fcntl(pout[1], F_SETFD, FD_CLOEXEC);
        *pfdout = pout[1];
      }
    } else {
      if (pfdin)
        close(pin[0]);
      if (pfdout)
        close(pout[1]);
      return 0;
    }
  }
  return pid;
}

/* Execute an external program in a shell. */
int
shell_exec(int *pfdin, int *pfdout, const char *path, const char *const *arg)
{
  int argc, i;
  const char **narg;
  char *arg0 = NULL;
  int ret;

  for (argc = 0; arg[argc]; argc++) ;

  if (argc < 1)
    return -1;

  narg = mem_calloc(argc + 4, sizeof(const char *));

  narg[0] = "sh";
  narg[1] = "-c";

  if (argc > 1) {
    arg0 = mem_malloc(strlen(path) + 6);
    sprintf(arg0, "%s \"$@\"", path);
    narg[2] = arg0;

    for (i = 0; i < argc; i++)
      narg[i + 3] = arg[i];
    narg[argc + 3] = NULL;
  } else {
    narg[2] = path;
    narg[3] = NULL;
  }

  ret = fork_exec(pfdin, pfdout, *narg, narg);

  if (arg0)
    mem_free(arg0);
  mem_free(narg);

  return ret;
}

/* Wait for a child process to terminate. */
int child_wait(int *pfdin, int *pfdout, int pid)
{
  int stat;

  if (pfdin)
    close(*pfdin);
  if (pfdout)
    close(*pfdout);

  waitpid(pid, &stat, 0);
  return stat;
}

/* Display "Press any key to continue..." and wait for a key press. */
void press_any_key(void)
{
  struct termios t_attr_old, t_attr;

  tcgetattr(STDIN_FILENO, &t_attr_old);
  memcpy(&t_attr, &t_attr_old, sizeof(struct termios));
  t_attr.c_lflag &= ~(ICANON | ECHO | ECHONL);
  tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_attr);

  fflush(stdout);
  fputs(_("Press any key to continue..."), stdout);
  fflush(stdout);
  fgetc(stdin);
  fflush(stdin);
  fputs("\r\n", stdout);

  tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_attr_old);
}

/*
 * Display note contents if one is asociated with the currently displayed item
 * (to be used together with the '-a' or '-t' flag in non-interactive mode).
 * Each line begins with nbtab tabs.
 * Print "No note file found", if the notefile does not exists.
 *
 * (patch submitted by Erik Saule).
 */
static void print_notefile(FILE * out, const char *filename, int nbtab)
{
  char path_to_notefile[BUFSIZ];
  FILE *notefile;
  char linestarter[BUFSIZ];
  char buffer[BUFSIZ];
  int i;
  int printlinestarter = 1;

  if (nbtab < BUFSIZ) {
    for (i = 0; i < nbtab; i++)
      linestarter[i] = '\t';
    linestarter[nbtab] = '\0';
  } else
    linestarter[0] = '\0';

  snprintf(path_to_notefile, BUFSIZ, "%s/%s", path_notes, filename);
  notefile = fopen(path_to_notefile, "r");
  if (notefile) {
    while (fgets(buffer, BUFSIZ, notefile) != 0) {
      if (printlinestarter) {
        fputs(linestarter, out);
        printlinestarter = 0;
      }
      fputs(buffer, out);
      if (buffer[strlen(buffer) - 1] == '\n')
        printlinestarter = 1;
    }
    fputs("\n", out);
    file_close(notefile, __FILE_POS__);
  } else {
    fputs(linestarter, out);
    fputs(_("No note file found\n"), out);
  }
}

/* Print an escape sequence and return its length. */
static int print_escape(const char *s)
{
  switch (*(s + 1)) {
  case 'a':
    putchar('\a');
    return 1;
  case 'b':
    putchar('\b');
    return 1;
  case 'f':
    putchar('\f');
    return 1;
  case 'n':
    putchar('\n');
    return 1;
  case 'r':
    putchar('\r');
    return 1;
  case 't':
    putchar('\t');
    return 1;
  case 'v':
    putchar('\v');
    return 1;
  case '0':
    putchar('\0');
    return 1;
  case '\'':
    putchar('\'');
    return 1;
  case '"':
    putchar('"');
    return 1;
  case '\?':
    putchar('?');
    return 1;
  case '\\':
    putchar('\\');
    return 1;
  case '\0':
    return 0;
  default:
    return 1;
  }
}

/* Parse a format specifier. */
static enum format_specifier parse_fs(const char **s, char *extformat)
{
  char buf[FS_EXT_MAXLEN];
  int i;

  extformat[0] = '\0';

  switch (**s) {
  case 's':
    strcpy(extformat, "epoch");
    return FS_STARTDATE;
  case 'S':
    return FS_STARTDATE;
  case 'd':
    return FS_DURATION;
  case 'e':
    strcpy(extformat, "epoch");
    return FS_ENDDATE;
  case 'E':
    return FS_ENDDATE;
  case 'm':
    return FS_MESSAGE;
  case 'n':
    return FS_NOTE;
  case 'N':
    return FS_NOTEFILE;
  case 'p':
    return FS_PRIORITY;
  case '(':
    /* Long format specifier. */
    for ((*s)++, i = 0; **s != ':' && **s != ')'; (*s)++, i++) {
      if (**s == '\0')
        return FS_EOF;

      if (i < FS_EXT_MAXLEN)
        buf[i] = **s;
    }

    buf[(i < FS_EXT_MAXLEN) ? i : FS_EXT_MAXLEN - 1] = '\0';

    if (**s == ':') {
      for ((*s)++, i = 0; **s != ')'; (*s)++, i++) {
        if (**s == '\0')
          return FS_EOF;

        if (i < FS_EXT_MAXLEN)
          extformat[i] = **s;
      }

      extformat[(i < FS_EXT_MAXLEN) ? i : FS_EXT_MAXLEN - 1] = '\0';
    }

    if (!strcmp(buf, "start"))
      return FS_STARTDATE;
    else if (!strcmp(buf, "duration"))
      return FS_DURATION;
    else if (!strcmp(buf, "end"))
      return FS_ENDDATE;
    else if (!strcmp(buf, "message"))
      return FS_MESSAGE;
    else if (!strcmp(buf, "noteid"))
      return FS_NOTE;
    else if (!strcmp(buf, "note"))
      return FS_NOTEFILE;
    else if (!strcmp(buf, "priority"))
      return FS_PRIORITY;
    else
      return FS_UNKNOWN;
  case '%':
    return FS_PSIGN;
  case '\0':
    return FS_EOF;
  default:
    return FS_UNKNOWN;
  }
}

/* Print a formatted date to stdout. */
static void print_date(long date, long day, const char *extformat)
{
  char buf[BUFSIZ];

  if (!strcmp(extformat, "epoch"))
    printf("%ld", date);
  else {
    time_t t = date;
    struct tm lt;

    localtime_r((time_t *)&t, &lt);

    if (extformat[0] == '\0' || !strcmp(extformat, "default")) {
      if (date >= day && date <= day + DAYINSEC)
        strftime(buf, BUFSIZ, "%H:%M", &lt);
      else
        strftime(buf, BUFSIZ, "..:..", &lt);
    } else {
      strftime(buf, BUFSIZ, extformat, &lt);
    }

    printf("%s", buf);
  }
}

/* Print a formatted appointment to stdout. */
void print_apoint(const char *format, long day, struct apoint *apt)
{
  const char *p;
  char extformat[FS_EXT_MAXLEN];

  for (p = format; *p; p++) {
    if (*p == '%') {
      p++;
      switch (parse_fs(&p, extformat)) {
      case FS_STARTDATE:
        print_date(apt->start, day, extformat);
        break;
      case FS_DURATION:
        printf("%ld", apt->dur);
        break;
      case FS_ENDDATE:
        print_date(apt->start + apt->dur, day, extformat);
        break;
      case FS_MESSAGE:
        printf("%s", apt->mesg);
        break;
      case FS_NOTE:
        printf("%s", apt->note);
        break;
      case FS_NOTEFILE:
        print_notefile(stdout, apt->note, 1);
        break;
      case FS_PSIGN:
        putchar('%');
        break;
      case FS_EOF:
        return;
        break;
      default:
        putchar('?');
        break;
      }
    } else if (*p == '\\')
      p += print_escape(p);
    else
      putchar(*p);
  }
}

/* Print a formatted event to stdout. */
void print_event(const char *format, long day, struct event *ev)
{
  const char *p;
  char extformat[FS_EXT_MAXLEN];

  for (p = format; *p; p++) {
    if (*p == '%') {
      p++;
      switch (parse_fs(&p, extformat)) {
      case FS_MESSAGE:
        printf("%s", ev->mesg);
        break;
      case FS_NOTE:
        printf("%s", ev->note);
        break;
      case FS_NOTEFILE:
        print_notefile(stdout, ev->note, 1);
        break;
      case FS_PSIGN:
        putchar('%');
        break;
      case FS_EOF:
        return;
        break;
      default:
        putchar('?');
        break;
      }
    } else if (*p == '\\')
      p += print_escape(p);
    else
      putchar(*p);
  }
}

/* Print a formatted recurrent appointment to stdout. */
void
print_recur_apoint(const char *format, long day, unsigned occurrence,
                   struct recur_apoint *rapt)
{
  struct apoint apt;

  apt.start = occurrence;
  apt.dur = rapt->dur;
  apt.mesg = rapt->mesg;
  apt.note = rapt->note;

  print_apoint(format, day, &apt);
}

/* Print a formatted recurrent event to stdout. */
void print_recur_event(const char *format, long day, struct recur_event *rev)
{
  struct event ev;

  ev.mesg = rev->mesg;
  ev.note = rev->note;

  print_event(format, day, &ev);
}

/* Print a formatted todo item to stdout. */
void print_todo(const char *format, struct todo *todo)
{
  const char *p;
  char extformat[FS_EXT_MAXLEN];

  for (p = format; *p; p++) {
    if (*p == '%') {
      p++;
      switch (parse_fs(&p, extformat)) {
      case FS_PRIORITY:
        printf("%d", abs(todo->id));
        break;
      case FS_MESSAGE:
        printf("%s", todo->mesg);
        break;
      case FS_NOTE:
        printf("%s", todo->note);
        break;
      case FS_NOTEFILE:
        print_notefile(stdout, todo->note, 1);
        break;
      case FS_PSIGN:
        putchar('%');
        break;
      case FS_EOF:
        return;
        break;
      default:
        putchar('?');
        break;
      }
    } else if (*p == '\\')
      p += print_escape(p);
    else
      putchar(*p);
  }
}