path: root/src/utils.c

/*
 * Calcurse - text-based organizer
 *
 * Copyright (c) 2004-2012 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 "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;

  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)
{
  day_free_list ();
  event_llist_free ();
  event_free_bkp ();
  apoint_llist_free ();
  apoint_free_bkp ();
  recur_apoint_llist_free ();
  recur_event_llist_free ();
  recur_apoint_free_bkp ();
  recur_event_free_bkp ();
  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);
  mvwprintw (errwin, 3, 1, reportmsg);
  mvwprintw (errwin, 5, (WINCOL - strlen (msg)) / 2, "%s", msg);
  custom_remove_attr (errwin, ATTR_HIGHEST);
  wins_wrefresh (errwin);
  wgetch (errwin);
  delwin (errwin);
  wins_doupdate ();
}

void
warnbox (const char *msg)
{
  WINDOW *warnwin;
  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);
  mvwprintw (warnwin, 5, (WINCOL - strlen (displmsg)) / 2, "%s", 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);
  mvwprintw (win[STA].p, 0, 0, msg1);
  mvwprintw (win[STA].p, 1, 0, msg2);
  custom_remove_attr (win[STA].p, ATTR_HIGHEST);
}

/* Print a status message, followed by a "[y/n]" prompt. */
void
status_mesg_yesno (const char *msg)
{
  status_mesg (msg, "[y/n] ");
}

/* 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++)
        mvwprintw (win, r, c, " ");
    }
}

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

  popup_win = newwin (pop_row, pop_col, pop_y, pop_x);
  keypad (popup_win, TRUE);
  if (msg)
    mvwprintw (popup_win, MSGXPOS, (pop_col - strlen (msg)) / 2, "%s", msg);
  custom_apply_attr (popup_win, ATTR_HIGHEST);
  box (popup_win, 0, 0);
  snprintf (label, BUFSIZ, "%s", title);
  wins_show (popup_win, label);
  if (hint)
    mvwprintw (popup_win, pop_row - 2, pop_col - (strlen (any_key) + 1), "%s",
               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);
  mvwprintw (win, y, x, "%s", 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)
{
  return (localtime ((time_t *)&date))->tm_hour;
}

int
get_item_min (long date)
{
  return (localtime ((time_t *)&date))->tm_min;
}

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

  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, char *datefmt)
{
  struct tm *lt;
  char *datestr = (char *) mem_calloc (BUFSIZ, sizeof (char));

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

  return datestr;
}

/* Generic function to format date. */
void
date_sec2date_fmt (long sec, const char *fmt, char *datef)
{
  struct tm *lt = localtime ((time_t *)&sec);
  strftime (datef, BUFSIZ, fmt, lt);
}

/*
 * 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;
  lt = localtime (&t);
  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;
  lt = localtime (&t);
  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);
      ptrtime = localtime (&timer);
      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 (char *saved_a_start, char *saved_a_end, char *msg,
               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 (strcmp (pop_title, _("Appointment")) == 0)
    {
      mvwprintw (popup_win, margin_top, margin_left, "- %s -> %s",
                 saved_a_start, saved_a_end);
    }
  mvwprintw (pad, 0, margin_left, "%s", 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);
  lt = localtime (&current_time);
  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)
{
  static char buf[BUFSIZ];
  time_t t = now ();

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

  return buf;
}

long
mystrtol (const char *str)
{
  char *ep;
  long lval;

  errno = 0;
  lval = strtol (str, &ep, 10);
  if (str[0] == '\0' || *ep != '\0')
    EXIT (_("could not convert string"));
  if (errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN))
    EXIT (_("out of range"));

  return lval;
}

/* 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);
  mvwprintw (win, pos_y, pos_x, "%s", 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'))
        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)".
 *
 * Note that this function performs an additional range check on each token to
 * ensure we do not accept semantically invalid strings such as "42:23".
 *
 * 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')
                {
                  if (in >= DAYINHOURS)
                    return 0;
                  dur += in * HOURINMIN;
                  state = STATE_DDHHMM_MM;
                }
              else if (*p == 'm')
                {
                  if (in >= HOURINMIN)
                    return 0;
                  dur += in;
                  state = STATE_DONE;
                }
              else
                return 0;
              break;
            case STATE_DDHHMM_HH:
              if (*p == 'h')
                {
                  if (in >= DAYINHOURS)
                    return 0;
                  dur += in * HOURINMIN;
                  state = STATE_DDHHMM_MM;
                }
              else if (*p == 'm')
                {
                  if (in >= HOURINMIN)
                    return 0;
                  dur += in;
                  state = STATE_DONE;
                }
              else
                return 0;
              break;
            case STATE_DDHHMM_MM:
              if (*p == 'm')
                {
                  if (in >= HOURINMIN)
                    return 0;
                  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
str_toupper (char *s)
{
  if (!s)
    return;
  for (; *s; s++)
    *s = toupper (*s);
}

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, 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, 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, char *cmd)
{
  char *arg[] = { "/bin/sh", "-c", cmd, NULL };
  return fork_exec (pfdin, pfdout, *arg, arg);
}

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

/*
 * 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, 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, const char *extformat)
{
  char buf[BUFSIZ];

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

      if (extformat[0] == '\0' || !strcmp (extformat, "default"))
        strftime (buf, BUFSIZ, "%H:%M", 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, extformat);
            break;
          case FS_DURATION:
            printf ("%ld", apt->dur);
            break;
          case FS_ENDDATE:
            print_date (apt->start + apt->dur, 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);
    }
}