DragonFly On-Line Manual Pages
DELAY(1) OneGeek Software DELAY(1)
delay - counts down a specified number of seconds.
delay [options] <length> [-- command]
delay [options] until <timespec> [-- command]
The delay program counts down a length of time specified on the command
line. By default, it prints out the time remaining once a second. The
rate and style of printing can be controlled using options to the
program. This includes the ability to supress the printing entirely. It
also somewhat supports delaying for fractional seconds.
Delay attempts to compensate for the time it spends printing the
updates. There should be no error that is a multiple of the time spent
delaying. (There is a bit of error on the startup and termination of
the program, but that's unavoidable.)
There are several ways that the time to delay can be specified. The
first is that it can be specified as an absolute length of time to
delay. This can be in several formats. All of the following formats are
allowable. (And equivalent.)
delay 1d 2:03:04.5
delay 1d 2h 3m 4.5s
Please note that the fractional seconds code will only work for actual
fractional seconds. So, doing things like '0.5h' will delay for half a
second, and not for half an hour as one may expect. (But don't rely on
this behavior, as it may change in future versions.)
The second format is for a time to delay until be specified. The time
parsing code is derived from that used it at, and as a result the time
specifications should be described on at(1). For example:
delay until 4 pm
delay until noon tomorrow
delay until midnight 13 september 2000
delay until now + 5 minutes
Please note that the parsing code has a resolution of a minute. So, the
last specification would calculate the 5 minutes from the beginning of
the current minute, and delay to that absolute point in time. If you
need more precision, you can use the first time format, which allows an
the delay length to be specified precisely.
If delay sees "--" while parsing it's command line, it stops argument
processing. Instead, the argument after the "--" is interpreted as a
command to be run when delay completes, and any further arguments are
used as arguments to that command. For example:
delay until 9:30 -- cdplay
Delay allows you to use command line options to control aspects of its
behavior. Here's a list:
-q This enables quiet mode. This prevents delay from outputting the
time remaining as it usually does. (This is the default if delay is
called with "sleep" as part of the program name.)
-m This enables a minimalistic count of the time remaining, with only
the number of seconds left being displayed. This was the default
for delay 1.0.
-d This enables the default display. The day, hour, minute, and second
are all broken out into seperate entrys. (This is the default,
except for the cases where -q is the default.)
-v This enables a more verbose mode of display. (It adds some
explanitory text, as compared to -d.)
-c This allows you to specify a custom time prompt. Printf-style
formatting is performed, with the following being allowed as the
possible percent substitutions:
%d Days remaining
%h Hours remaining (modulo 24)
%m Minutes remaining (modulo 60)
%s Seconds remaining (modulo 60)
%n Total seconds remaining
For best results, you'll want to make sure that your custom format
stays the same length throughout the count. Printf-style formatting
is done on these codes. Use of percent-codes other than the ones
listed above will lead to undefined behavior. (Crashes, usually.)
The following escapes are also supported:
\r Carriage Return
Since the custom format no longer implicitly begins with a carriage
return, it usually makes sense to either begin a custom code with
\r or end it with \n.
The standard formats can be expressed as custom codes. Here's a
list of translations.
-m \r% 8n
-d \r% 3d %02h:%02m:%02s
-v \rTime Remaining: %d days, %02h:%02m:%02s.
-C This option enables the display of time remaining in big ugly
curses numerals. This only displays the hours, minutes, and seconds
remaining, although the number of hours to go may range above 24.
-u This option takes a single parameter, the time in seconds between
updates of the time remaining. It need not be a factor of the delay
length. It defaults to 1 second, and must be at least that value.
-b If this option is given, a bell character will be sent when time
expires. This may be useful in cases where an xterm is send to de-
iconify on a bell.
-V If given, delay will display it's version and a short copyright
message, and will then exit.
The default format is only good for delays of less than 1000 days.
Improper use of the -c option can lead to various problems, and may
even have some security implications.
execvp(2) is used to run the command, and this may run programs in the
current directory rather than fully respecting your path. Please see
execvp(2) for more details.
Tom Rothamel <firstname.lastname@example.org>
The delay web site is located at:
sleep(1), printf(3), at(1)
3rd Berkeley Distribution 2002-02-09 DELAY(1)
delay_output, filter, flushinp, getwin, key_name, keyname, nofilter,
putwin, unctrl, use_env, use_tioctl, wunctrl - miscellaneous curses
const char *unctrl(chtype c);
wchar_t *wunctrl(cchar_t *c);
const char *keyname(int c);
const char *key_name(wchar_t w);
void use_env(bool f);
void use_tioctl(bool f);
int putwin(WINDOW *win, FILE *filep);
WINDOW *getwin(FILE *filep);
int delay_output(int ms);
The unctrl routine returns a character string which is a printable
representation of the character c, ignoring attributes. Control
characters are displayed in the ^X notation. Printing characters are
displayed as is. The corresponding wunctrl returns a printable
representation of a wide character.
The keyname routine returns a character string corresponding to the key
o Printable characters are displayed as themselves, e.g., a one-
character string containing the key.
o Control characters are displayed in the ^X notation.
o DEL (character 127) is displayed as ^?.
o Values above 128 are either meta characters (if the screen has not
been initialized, or if meta(3X) has been called with a TRUE
parameter), shown in the M-X notation, or are displayed as
themselves. In the latter case, the values may not be printable;
this follows the X/Open specification.
o Values above 256 may be the names of the names of function keys.
o Otherwise (if there is no corresponding name) the function returns
null, to denote an error. X/Open also lists an "UNKNOWN KEY"
return value, which some implementations return rather than null.
The corresponding key_name returns a character string corresponding to
the wide-character value w. The two functions do not return the same
set of strings; the latter returns null where the former would display
a meta character.
The filter routine, if used, must be called before initscr or newterm
are called. Calling filter causes these changes in initialization:
o LINES is set to 1;
o the capabilities clear, cud1, cud, cup, cuu1, cuu, vpa are
o the capability ed is disabled if bce is set;
o and the home string is set to the value of cr.
The nofilter routine cancels the effect of a preceding filter call.
That allows the caller to initialize a screen on a different device,
using a different value of $TERM. The limitation arises because the
filter routine modifies the in-memory copy of the terminal information.
The use_env routine, if used, should be called before initscr or
newterm are called (because those compute the screen size). It
modifies the way ncurses treats environment variables when determining
the screen size.
o Normally ncurses looks first at the terminal database for the
If use_env was called with FALSE for parameter, it stops here
unless use_tioctl was also called with TRUE for parameter.
o Then it asks for the screen size via operating system calls. If
successful, it overrides the values from the terminal database.
o Finally (unless use_env was called with FALSE parameter), ncurses
examines the LINES or COLUMNS environment variables, using a value
in those to override the results from the operating system or
Ncurses also updates the screen size in response to SIGWINCH,
unless overridden by the LINES or COLUMNS environment variables,
The use_tioctl routine, if used, should be called before initscr or
newterm are called (because those compute the screen size). After
use_tioctl is called with TRUE as an argument, ncurses modifies the
last step in its computation of screen size as follows:
o checks if the LINES and COLUMNS environment variables are set to a
number greater than zero.
o for each, ncurses updates the corresponding environment variable
with the value that it has obtained via operating system call or
from the terminal database.
o ncurses re-fetches the value of the environment variables so that
it is still the environment variables which set the screen size.
The use_env and use_tioctl routines combine as summarized here:
use_env use_tioctl Summary
TRUE FALSE This is the default behavior. ncurses
uses operating system calls unless
overridden by $LINES or $COLUMNS
TRUE TRUE ncurses updates $LINES and $COLUMNS
based on operating system calls.
FALSE TRUE ncurses ignores $LINES and $COLUMNS,
uses operating system calls to obtain
FALSE FALSE ncurses relies on the terminal database
to determine size.
The putwin routine writes all data associated with window (or pad) win
into the file to which filep points. This information can be later
retrieved using the getwin function.
The getwin routine reads window related data stored in the file by
putwin. The routine then creates and initializes a new window using
that data. It returns a pointer to the new window. There are a few
o the data written is a copy of the WINDOW structure, and its
associated character cells. The format differs between the wide-
character (ncursesw) and non-wide (ncurses) libraries. You can
transfer data between the two, however.
o the retrieved window is always created as a top-level window (or
pad), rather than a subwindow.
o the window's character cells contain the color pair value, but not
the actual color numbers. If cells in the retrieved window use
color pairs which have not been created in the application using
init_pair, they will not be colored when the window is refreshed.
The delay_output routine inserts an ms millisecond pause in output.
This routine should not be used extensively because padding characters
are used rather than a CPU pause. If no padding character is
specified, this uses napms to perform the delay.
The flushinp routine throws away any typeahead that has been typed by
the user and has not yet been read by the program.
Except for flushinp, routines that return an integer return ERR upon
failure and OK (SVr4 specifies only "an integer value other than ERR")
upon successful completion.
Routines that return pointers return NULL on error.
X/Open does not define any error conditions. In this implementation
returns an error if the terminal was not initialized.
returns an error if the associated fwrite calls return an
The SVr4 documentation describes the action of filter only in the
vaguest terms. The description here is adapted from the XSI Curses
standard (which erroneously fails to describe the disabling of cuu).
The keyname function may return the names of user-defined string
capabilities which are defined in the terminfo entry via the -x option
of tic. This implementation automatically assigns at run-time keycodes
to user-defined strings which begin with "k". The keycodes start at
KEY_MAX, but are not guaranteed to be the same value for different runs
because user-defined codes are merged from all terminal descriptions
which have been loaded. The use_extended_names(3X) function controls
whether this data is loaded when the terminal description is read by
The nofilter and use_tioctl routines are specific to ncurses. They
were not supported on Version 7, BSD or System V implementations. It
is recommended that any code depending on ncurses extensions be
conditioned using NCURSES_VERSION.
The putwin and getwin functions have several issues with portability:
o The files written and read by these functions use an
implementation-specific format. Although the format is an obvious
target for standardization, it has been overlooked.
Interestingly enough, according to the copyright dates in Solaris
source, the functions (along with scr_init, etc.) originated with
the University of California, Berkeley (in 1982) and were later (in
1988) incorporated into SVr4. Oddly, there are no such functions
in the 4.3BSD curses sources.
o Most implementations simply dump the binary WINDOW structure to the
file. These include SVr4 curses, NetBSD and PDCurses, as well as
older ncurses versions. This implementation (as well as the X/Open
variant of Solaris curses, dated 1995) uses textual dumps.
The implementations which use binary dumps use block-I/O (the
fwrite and fread functions). Those that use textual dumps use
buffered-I/O. A few applications may happen to write extra data in
the file using these functions. Doing that can run into problems
mixing block- and buffered-I/O. This implementation reduces the
problem on writes by flushing the output. However, reading from a
file written using mixed schemes may not be successful.
The XSI Curses standard, Issue 4 describes these functions. It states
that unctrl and wunctrl will return a null pointer if unsuccessful, but
does not define any error conditions. This implementation checks for
o the parameter is a 7-bit US-ASCII code. This is the case that
X/Open Curses documented.
o the parameter is in the range 128-159, i.e., a C1 control code. If
use_legacy_coding(3X) has been called with a 2 parameter, unctrl
returns the parameter, i.e., a one-character string with the
parameter as the first character. Otherwise, it returns "~@",
"~A", etc., analogous to "^@", "^A", C0 controls.
X/Open Curses does not document whether unctrl can be called before
initializing curses. This implementation permits that, and returns
the "~@", etc., values in that case.
o parameter values outside the 0 to 255 range. unctrl returns a null
The strings returned by unctrl in this implementation are determined at
compile time, showing C1 controls from the upper-128 codes with a "~"
prefix rather than "^". Other implementations have different
conventions. For example, they may show both sets of control
characters with "^", and strip the parameter to 7 bits. Or they may
ignore C1 controls and treat all of the upper-128 codes as printable.
This implementation uses 8 bits but does not modify the string to
reflect locale. The use_legacy_coding(3X) function allows the caller
to change the output of unctrl.
Likewise, the meta(3X) function allows the caller to change the output
of keyname, i.e., it determines whether to use the "M-" prefix for
"meta" keys (codes in the range 128 to 255). Both
use_legacy_coding(3X) and meta(3X) succeed only after curses is
initialized. X/Open Curses does not document the treatment of codes
128 to 159. When treating them as "meta" keys (or if keyname is called
before initializing curses), this implementation returns strings
"M-^@", "M-^A", etc.
X/Open Curses documents unctrl as declared in <unctrl.h>, which ncurses
does. However, ncurses' <curses.h> includes <unctrl.h>, matching the
behavior of SVr4 curses. Other implementations may not do that.
If ncurses is configured to provide the sp-functions extension, the
state of use_env and use_tioctl may be updated before creating each
screen rather than once only (curs_sp_funcs(3X)). This feature of
use_env is not provided by other implementation of curses.
curses(3X), curs_initscr(3X), curs_inopts(3X), curs_kernel(3X),
curs_scr_dump(3X), curs_sp_funcs(3X), curs_variables(3X),