This is gcal.info, produced by makeinfo version 4.0 from gcal.texi.

INFO-DIR-SECTION GNU packages
START-INFO-DIR-ENTRY
* Gcal: (gcal).                       GNU calendar program.
* Tcal: (gcal)Invoking tcal.          Run Gcal with tomorrow's date.
* Txt2gcal: (gcal)Invoking txt2gcal.  Calendar text to resource file.
* Gcal2txt: (gcal)Invoking gcal2txt.  Calendar resource to text file.
END-INFO-DIR-ENTRY

  This file documents Gcal, a program for calculating and printing
calendars.

  Copyright (c) 1994-1997, 2000 Thomas Esken

  This edition is for Gcal version 3.00.

  Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

  Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

  Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be stated in a
translation approved by the Free Software Foundation.

  Any suggestions, improvements, extensions, bug reports, donations,
proposals for contract work, and so forth are welcome!  Please send
them directly to my eMail address <esken@gmx.net>.  If you like my
work, I'd appreciate a postcard from you!

------------------------oOO      \\\_''/      OOo---------------------------
Thomas Esken               O     (/o-o\)     O  eMail: esken@gmx.net
Im Hagenfeld 84                 ((  ^  ))       Phone: +49 251 232585
D-48147 Muenster; Germany    \____) ~ (____/    MotD : 2old2live, 2young2die


File: gcal.info,  Node: Ranges of days,  Next: Repetition factor of days,  Prev: Lists of days,  Up: Further date part attributes

Ranges of days
..............

  A range of days just as a list of days is used to define recurrent
fixed dates and to use only one line in the resource file for them,
instead of using several lines in a resource file needed for defining
these recurrent fixed dates separately.

  A range of days is specified by a `#' separator character and must
consist of two elements, namely the starting day and the final day.
The starting day and likewise the final day of the range may not be set
to a zero value and be not concrete therefore.  (This would not make
any sense in this context.)

  Assuming a fixed date shall always occur during the 1st and the 15th
day (inclusive) in every month of the year 1996, e.g. `Inside work',
one solution would be on the one hand a fixed date entry in the resource
file for the 1st of the month, another one for the 2nd of the month
until the 15th of the month, which would be a total of 15 entries in
the resource file for such a fixed date(1) (*note Ranges of
days-Footnote-1::).

  On the other hand, this expense can be reduced to a total of only one
entry in the resource file by using a range of days, which is likewise
valid for the 1st until the 15th day in every month, that is

     19960001#15 Inside work

The use of ranges of days in the date part is permitted as follows:

   * `YYYYMMWWW#WWW'

   * `YYYYMMDD|WWWN#[MM]DD|[MM]WWWN'

   * `YYYY*d|wN[WWW]#N[WWW]'

   * `YYYY@e|t|DVAR[[+|-]N[WWW]]#[+|-]N[WWW]'

  Preceding table shows that the starting and ending day can only be
specified by using date formats of the same type left and right the `#'
separator character.  Thus, it is not explicitly possible to define a
range of days by using different types of date formats, means, fixed
date entries like:

     1996@e+3fr#1012 In the year 1996: every day that appears within the\
                     period of the date 3 Fridays after Easter Sunday's\
                     date until the 12th October.

cannot be defined like this.  But this problem can be solved by using an
inclusive date period `%i[DATE][#[DATE]]' special text for defining the
ending day of the range(2) (*note Ranges of days-Footnote-2::), and the
fixed dates are simply produced until the last day of the year, e.g.:

     1996@e+3fr#+999 In the year 1996: every day that appears within the\
                     period of the date 3 Fridays after Easter Sunday's\
                     date until the 12th October.%i0#19961012

  *Note Inclusive date period `%i[DATE][#[DATE]]' special text:
Inclusive date period, for more details.

Some examples to this:

`199600mon#fr'
     In the year 1996 in every month: every day that appears within the
     day sequence `mon, tue, wed, thu, fri'.

`000000fr#mon'
     In every year in every month: every day that appears within the day
     sequence `fri, sat, sun, mon'.

`000001fr3#12'
     In every year in January: every day that appears within the period
     of the 3rd Friday of the month until the 12th of the month.

`00000112#fr3'
     In every year in January: every day that appears within the period
     of the 12th of the month until the 3rd Friday of the month.

`00000112#augfri3'
     In every year: every day that appears within the period of the
     12th January until the 3rd Friday of August.

`0000sep13#99fr9'
     In every year: every day that appears within the period of the
     13th September until the last Friday of December.

`0*d1#1fr'
     In every year: every day that appears within the period of the 1st
     day of the year until the 1rd Friday of the year.

`0*d99fr#333'
     In every year: every day that appears within the period of the
     last Friday of the year until the 333rd day of the year.

`1996*w1fr#17mo'
     In the year 1996: every day that appears within the period of the
     Friday of the 1st week until the Monday of the 17th week.

`0@a#+4fr'
     In every year: every day that appears within the period of the
     date of the date variable A until the 4th Friday after the date of
     the date variable A.

`1996@e-3#+9fr'
     In the year 1996: every day that appears within the period of the
     date three days before the Easter Sunday's date until the 9th
     Friday after the date of the Easter Sunday's date.

`1996@t-3#+99fr'
     In the year 1996: every day that appears within the period of the
     date three days before today's date until the last Friday of the
     year.


File: gcal.info,  Node: Ranges of days-Footnotes,  Up: Ranges of days

  (1) Apart from the possibility, that a list of days can be used in
such a case.

  (2) Implicit solution.


File: gcal.info,  Node: Repetition factor of days,  Next: Appearance factor of days,  Prev: Ranges of days,  Up: Further date part attributes

Repetition factor of days
.........................

  A repetition factor of days is used to define recurrent fixed dates
and to use only one line in the resource file for them, instead of
using several lines in a resource file needed for defining these
recurrent fixed dates separately.

  A repetition factor of days (`:N') is specified by a `:' character
and must trail the day field --which must have a concrete value in a
date part of a Gcal resource file and has not been set to a zero
value-- respectively either lead or trail an appearance factor of days.
Except ranges of days or fixed dates which occur only on a definite
weekday like `199600mon Every Monday 1996', such a repetition factor
may be specified in all possible codings of date parts of a Gcal
resource file.

  This factor may have values in range `1...999'.  Values greater than
the real difference between the date of the first occurrence of the
fixed date and the last day of the year are always reduced to this real
difference.  In this sense, any value greater `365'(1) (*note
Repetition factor of days-Footnote-1::) means a repetition factor until
the last day of the year.

  Assuming a fixed date shall always occur on the 15th day in every
month of the year 1996 and covers a period of four days (inclusive the
15th itself), e.g. `Co-workers training', one solution would be on the
one hand a fixed date entry in the resource file for the 15th of the
month and the succeeding three days, which would be a total of four
entries in the resource file for such a fixed date(2) (*note Repetition
factor of days-Footnote-2::).

  On the other hand, this expense can be reduced to a total of only one
entry in the resource file by using a repetition factor of days, which
is likewise valid for the 15th and the three days which succeed the
15th in every month, namely

     19960015:4 Co-workers training

The use of repetition factors of days in the date part is permitted as
follows:

   * `YYYYMMDD:N|WWWN:N'

   * `YYYY*d|wN:N|NWWW:N'

   * `YYYY@e|t|DVAR[[+|-]N[WWW]]:N'

   * `YYYYMMDD:N|WWWN:N,[MM]DD:N|[MM]WWWN:N ...'

   * `YYYY*d|wN:N|NWWW:N,N:N|NWWW:N ...'

   * `YYYY@e|t|DVAR:N,|[+|-]N[WWW]:N,[+|-]N[WWW]:N ...'

Some examples to this:

`000001fr3:11'
     In every year in January: every day that appears within the period
     of the 3rd Friday of the month and the succeeding ten days.

`00000112:3'
     In every year in January: every day that appears within the period
     of the 12th of the month and the succeeding two days.

`00000112:3,fr3:5'
     In every year in January: every day that appears within the period
     of the 12th of the month and the succeeding two days, and that
     appears within the period of the 3rd Friday of the month and the
     succeeding four days.

`0*d1:1'
     In every year: every day that appears within the period of the 1st
     day of the year and no succeeding day.

`0*d1:2'
     In every year: every day that appears within the period of the 1st
     day of the year and the succeeding day.

`0*d99fr:333'
     In every year: every day that appears within the period of the
     last Friday of the year and the succeeding 332 days.  Well, in
     cases a fixed date exceeds the year bounds, it will only be
     produced until the last day of the year.

`1996*w1fr:17'
     In the year 1996: every day that appears within the period of the
     Friday of the 1st week and the succeeding 16 days.

`0@a:4'
     In every year: every day that appears within the period of the
     date of the date variable A and the succeeding three days.

`1996@e-3:9'
     In the year 1996: every day that appears within the period of the
     date three days before the Easter Sunday's date and the succeeding
     eight days.

`1996@t-3:9'
     In the year 1996: every day that appears within the period of the
     date three days before today's date and the succeeding eight days.


File: gcal.info,  Node: Repetition factor of days-Footnotes,  Up: Repetition factor of days

  (1) Or `366' in leap years.

  (2) Apart from the possibility, that a list or a range of days can be
used in such a case.


File: gcal.info,  Node: Appearance factor of days,  Prev: Repetition factor of days,  Up: Further date part attributes

Appearance factor of days
.........................

  An appearance factor of days is used to define a concrete
displacement of recurrent fixed dates.

  An appearance factor of days (`.N') is specified by a `.' character
and must trail the day field --which must have a concrete value in a
date part of a Gcal resource file and has not been set to a zero
value-- respectively either lead or trail a repetition factor of days.
Except fixed dates which occur only on a definite weekday and are not
specified by using a range of days, like `199600mon Every Monday 1996',
such an appearance factor may be specified in all possible codings of
date parts of a Gcal resource file.  This factor may be specified with
each single element of lists of days, but in a range of days, this
factor may trail *only* the final day of the range.  Well, the use of
such an appearance factor is only helpful if it is either given in a
range of days, or if it is given together with a repetition factor.

  This factor may have values in range `1...999'.  Fixed dates will be
ignored if the factor takes values greater than the real difference
between the date of the occurrence of the fixed date and the last day
of the year, respectively the end of the period, for which the fixed
dates shall either be produced or respected.

  Assuming a fixed date shall always occur on the 15th day in every
month of the year 1996 and covers a period of seven days (inclusive the
15th itself), but shall only be respected every third day (i.e. two
days have to be skipped at a time) within this period, e.g.
`Training-college', one solution would be on the one hand a fixed date
entry in the resource file for the 15th of the month, for the 18th and
for the 21st of the month, which would be a total of three entries in
the resource file for such a fixed date(1) (*note Appearance factor of
days-Footnote-1::).

  On the other hand, this expense can be reduced to a total of only one
entry in the resource file by using an appearance factor of days, which
is likewise valid for the 15th, the 18th and the 21st in every month,
namely on the one hand by the use of a repetition factor

     19960015:7.3 Training-college

or on the other hand by the use of a range of days

     19960015#21.3 Training-college

The use of appearance factors of days in the date part is permitted as
follows:

   * `YYYYMMDD:N.N|DD.N:N'

   * `YYYYMMWWWN:N.N|WWWN.N:N'

   * `YYYY*d|wN:N.N|N.N:N'

   * `YYYY*d|wNWWW:N.N|NWWW.N:N'

   * `YYYY@e|t|DVAR[[+|-]N[WWW]]:N.N'

   * `YYYY@e|t|DVAR[[+|-]N[WWW]].N:N'

   * `YYYYMMDD:N.N|WWWN:N.N,[MM]DD:N.N|[MM]WWWN:N.N ...'

   * `YYYYMMDD.N:N|WWWN.N:N,[MM]DD:N.N|[MM]WWWN.N:N ...'

   * `YYYY*d|wN:N.N|NWWW:N.N,N:N.N|NWWW:N.N ...'

   * `YYYY*d|wN.N:N|NWWW.N:N,N.N:N|NWWW.N:N ...'

   * `YYYY@e|t|DVAR:N.N,|[+|-]N[WWW]:N.N,[+|-]N[WWW]:N.N ...'

   * `YYYY@e|t|DVAR.N:N,|[+|.]N[WWW].N:N,[+|.]N[WWW].N:N ...'

   * `YYYYMMWWW#WWW.N'

   * `YYYYMMDD|WWWN#[MM]DD|[MM]WWWN.N'

   * `YYYY*d|wN[WWW]#N[WWW].N'

   * `YYYY@e|t|DVAR[[+|-]N[WWW]]#[+|-]N[WWW].N'

Some examples to this:

`000001fr3:11.3'
     In every year in January: every day that appears within the period
     of the 3rd Friday of the month and the succeeding ten days, but
     only every 3rd day within this period (skip two days at a time).

`00000112:3.2'
     In every year in January: every day that appears within the period
     of the 12th of the month and the succeeding two days, but only
     every 2nd day within this period (skip one day at a time).

`00000112:3.2,fr3:5.3'
     In every year in January: every day that appears within the period
     of the 12th of the month and the succeeding two days, but only
     every 2nd day within this period (skip one day at a time), and that
     appears within the period of the 3rd Friday of the month and the
     succeeding four days, but only every 3rd day within this period
     (skip two days at a time).

`0*d1:10.1'
     In every year: every day that appears within the period of the 1st
     day of the year and the succeeding nine days, and this for any day
     within this period (skip zero days at a time).

`0*d1:2.5'
     In every year: every day that appears within the period of the 1st
     day of the year and the succeeding day, but only every 5th day
     within this period (skip four days at a time).  Well, the
     succeeding days (only one in this example) of the starting day
     (1st day of year) are not respected, because the next day resulted
     by the appearance factor exceeds the final day (resulted by the
     repetition factor) of the period.

`0*d99fr:333.61'
     In every year: every day that appears within the period of the
     last Friday of the year and the succeeding 332 days, but only
     every 61st day within this period (skip 60 days at a time).  Well,
     in cases a fixed date exceeds the year bounds, it will only be
     produced until the last day of the year.  No succeeding day (332
     in this example) of the starting day (last Friday of the year) is
     respected by reason of the displacement value of 60 days, because
     the next day resulted by the appearance factor exceeds the final
     day (resulted by the repetition factor) of the period (the last
     day of the year).

`1996*w1fr:17.8'
     In the year 1996: every day that appears within the period of the
     Friday of the 1st week and the succeeding 16 days, but only every
     8th day within this period (skip seven days at a time).

`0@a:4.3'
     In every year: every day that appears within the period of the
     date of the date variable A and the succeeding three days, but
     only every 3rd day within this period (skip two days at a time).

`1996@e-3:9.4'
     In the year 1996: every day that appears within the period of the
     date three days before the Easter Sunday's date and the succeeding
     eight days, but only every 4th day within this period (skip three
     days at a time).

`1996@e3#-20sun.15'
     In the year 1996: every day that appears within the period of the
     date three days after the Easter Sunday's date until the 20th
     Sunday before the Easter Sunday's date, but only every 15th day
     within this period (skip 14 days at a time).

`1996@t3#-20sun.15'
     In the year 1996: every day that appears within the period of the
     date three days after today's date until the 20th Sunday before
     today's date, but only every 15th day within this period (skip 14
     days at a time).


File: gcal.info,  Node: Appearance factor of days-Footnotes,  Up: Appearance factor of days

  (1) Apart from the possibility, that a list of days can be used in
such a case.


File: gcal.info,  Node: Text part of a line,  Next: Special Texts processed,  Prev: Further date part attributes,  Up: Resource file

Text part of a line
-------------------

  The "text part" of a line in a resource file can be any text you like.
Indeed, some characters have a special meaning (`%', `$', `~', `^' and
`\') and must be protected should the occasion arise that special
character combinations are formed with them(1) (*note Text part of a
line-Footnote-1::) which might be used only textually.  If the text part
contains characters that are used for highlighting the text or format
it for a printer, or characters with decimal values above 127 in the
code table of the used character set(2) (*note Text part of a
line-Footnote-2::) not produced by Gcal itself, such characters
respectively sequences are displayed by Gcal in an *uninterpreted*
manner!  For that very reason, it can happen that the output of such
characters can potentially create problems with the used screen device
driver software and/or the external pager program, likewise mailing of
such texts by means of electronic mail.

  So-called `NUL' characters(3) (*note Text part of a
line-Footnote-3::) may also occur in the text part, but they only cause
the suppression of all succeeding characters in the line.  In my
opinion, it makes no perceptible sense to output these `NUL' characters
uninterpreted, so they are used for remarking purposes only; besides,
the `NUL' characters would lead to the same problems as already
mentioned above.

  A line of the resource file is continued on the next line if a `\-\n'
(backslash-newline) character sequence is found, e.g.:

The line:
     000000Mo Every Monday

and the lines:
     000000Mo \
     Every \
     Monday

produce the same output and are essentially equivalent.

  Furthermore, you can break-up the text of a "long text part" at any
place you like.  The term _long_ means in this context, that the text
displayed by Gcal would override the right text margin of the screen
respectively break-up at that margin.

  Each time a `~' (tilde) character is found in the text part, this
character is replaced by a real `\n' (newline) character.  Such texts
will be displayed by Gcal in a formatted manner at a left margin, this
means, they are lead by a definite number of space characters.

  You may depreciate the special meaning of the `~' (tilde) character
--in case this character itself is needed-- by placing a `\'
(backslash) character before it, e.g. `\~'.  If you need the `\~'
characters themselves, you have to protect the `\' (backslash) character
by another `\' (backslash) character, e.g. `\\~'.

  Each time a `^' (caret) character is found in the text part, this
character is also replaced by a real `\n' (newline) character.  Such
texts will be displayed by Gcal at column 1, this means, they are not
lead by space characters.  The rules for protecting the `^' character
are the same as the rules used for protecting the `~' character.

The resource file `lbrk-1.rc'

     $ cat lbrk-1.rc
     -| ; Hi, I'm `lbrk-1.rc' and alive now
     -| ;
     -| 0 I know I'm a short text
     -| 0 I hope I'm long enough~here, a line break-up~\
     -| and again~and now for the last time...
     -| 0 I hope I'm also long enough^here, a line break-up\
     -| ~and again^and now for the last time...
     -| 0 Am I another short text? Dunno...

is displayed as follows:

     $ gcal %00000101 --resource-file=./lbrk-1.rc --disable-highlighting
     -|
     -| Fixed date list:
     -|
     -| Sat, Jan   1st 2000: Am I another short text? Dunno...
     -| Sat, Jan   1st 2000: I hope I'm also long enough
     -| here, a line break-up
     -|                      and again
     -| and now for the last time...
     -| Sat, Jan   1st 2000: I hope I'm long enough
     -|                      here, a line break-up
     -|                      and again
     -|                      and now for the last time...
     -| Sat, Jan   1st 2000: I know I'm a short text

  Because _whitespace_ characters are used to separate the date part
from the text part(4) (*note Text part of a line-Footnote-4::), it is
not possible to supply the text part with leading _whitespace_
characters without further ado.  If one or more _whitespace_ characters
shall lead the text part, this can be arranged by protecting the
*first* of these _whitespace_ characters (and that by placing a `\'
(backslash) character before it), e.g. `\ ' if it is a space character.
By means of such a character sequence, Gcal notices that the text
trailing the `\' character is no longer used for separating purposes,
but is member of the text part.  Gcal skips this specific, marking
backslash character (avoids its output) and processes the rest of the
line as usual.

  The following example should be enough to elucidate the above facts.
The resource file `wspc-1.rc'

     $ cat wspc-1.rc
     -| 0 BANG BANG
     -| 0 bogus
     -| 0         bogomips
     -| 0    \hello world
     -| 0    \ main(){for(;;)fork();}
     -| 0 \     sh $0 & $0 &
     -| 0    \  a  \  b  \\  c  \\\  d
     -| 0    What happens now?\
     -| ~0  \  This!
     -| 0    What happens now?\\
     -| ~0  \  That!

is displayed as follows:

     $ gcal --resource-file=./wspc-1.rc --disable-highlighting
     -|
     -| Fixed date list:
     -|
     -| Sat, Jun   3rd 2000:      sh $0 & $0 &
     -| Sat, Jun   3rd 2000:   a  \  b  \\  c  \\\  d
     -| Sat, Jun   3rd 2000:  main(){for(;;)fork();}
     -| Sat, Jun   3rd 2000: BANG BANG
     -| Sat, Jun   3rd 2000: What happens now?~0  \  That!
     -| Sat, Jun   3rd 2000: What happens now?
     -|                      0  \  This!
     -| Sat, Jun   3rd 2000: \hello world
     -| Sat, Jun   3rd 2000: bogomips
     -| Sat, Jun   3rd 2000: bogus


File: gcal.info,  Node: Text part of a line-Footnotes,  Up: Text part of a line

  (1) Like `%i', `$a'...

  (2) These are potentially non-printable.

  (3) That is the character with the value zero in the code table of
the used character set.

  (4) These are internally skipped and remain undisplayed therefore.


File: gcal.info,  Node: Special Texts processed,  Next: Comment line,  Prev: Text part of a line,  Up: Resource file

`%?'... Special Texts
---------------------

  The text part of a resource file line may be provided with different
special texts which may occur in any(1) (*note Special Texts
processed-Footnote-1::) number and order.  All these texts start with a
`%' (percent) character which may be protected by a leading `\'
(backslash) character if the `%' (percent) character itself is wanted
to be used in the text part, e.g. `\%'.  The `%' character is mostly
trailed by an optional format instruction, (see *Note Format
Instruction::, for the detailed description of the format instruction
and its components), and then trailed by a distinguishing mark --which
defines the kind of the special text to be used-- and if it is a
letter, Gcal accepts it *case-sensitive*.

  The purpose of these special texts is mainly to suppress output of
fixed dates in definite cases, either, or to provide them with
particular texts respectively to start external commands.  *Note
Description of all `%?'... Special Texts: Special Texts, for a complete
description of all usable special texts, and *Note Summary of all
`%?'... Special Texts: Special Texts Summary, for an according
short-list of them.

For example, the resource file `speci-1.rc'

     $ cat speci-1.rc
     -| ; I'm veracious very special :)
     -| ;
     -| 0 1. Today is %>1u*K , %>02&*D  %U  %Y !
     -| 0 2. It's the %>03&*N  day of the year.
     -| 0 3. The actual week number is: %k .
     -| 0 4. Currently, it's %t*  o'clock, Mr. %-USER .
     -| 0 5. Hurry up with your work~\
     -|    by reason sunrise is at %o+5158+00738+61,2: .

is displayed as follows (in case today's date is the 4th October 1996):

     $ gcal --resource-file=speci-1.rc -H no -ox
     -|
     -| Mon, Oct   4th 1999: 1. Today is MONDAY, 04th October 1999!
     -|                      2. It's the 277th day of the year.
     -|                      3. The actual week number is: 40.
     -|                      4. Currently, it's 04:05am o'clock, Mr. esken.
     -|                      5. Hurry up with your work
     -|                         by reason sunrise is at 07:33.


File: gcal.info,  Node: Special Texts processed-Footnotes,  Up: Special Texts processed

  (1) Rational!


File: gcal.info,  Node: Comment line,  Next: Include directives,  Prev: Special Texts processed,  Up: Resource file

Comment line
------------

  A line(1) (*note Comment line-Footnote-1::) beginning with a `;'
(semicolon) character in the resource file is treated as a remark and
will not be used by Gcal!  Any _whitespace_ characters may lead the
remark character.  *Note Text part of a line::, for information how a
`NUL' character can be used for remarking purposes in a text part.

  The following example of the `remark.rc' resource file --which *only*
consists of remarks-- should be enough to elucidate the above facts:

     $ cat remark.rc
     -| ;00001031 ^\
     -|                         .......^\
     -|                         ;::;::,^\
     -|                         ;::;::;,^\
     -|                        ;;::;;:;;,^\
     -|           .vmnv\%vnv\%,.;;;:::;;:;;,  .,vnmv\%vnn,^\
     -|        vmmmn\%vmmnv\%vnmmnv\%;;;;;;\%nmmmnv\%vnmv\%vmmv^\
     -|      vmmnv\%vmmmnv\%vnmmmmmnv\%;:\%nmmmmmmnv\%vnm\%vnmmmv^\
     -|     vmmnv\%vmmmnv\%vnmmmmmmmmnv\%nmmmmmmmmnv\%vnmm\%vnmmmv^\
     -|    vmmnv\%vmmmnv\%vnmmmmmmmmnv\%vmmmmmmmmmmnv\%vnmv\%vnmmmv^\
     -|   vmmnv\%vmmmnv\%vnmm;mmmmmmnv\%vmmmmmmmm;mmnv\%vnmv\%vnmmmv,^\
     -|  vmmnv\%vmmmnv\%vnmm;' mmmmmnv\%vmmmmmmm;' mmnv\%vnmv\%vnmmmv,^\
     -|  vmmnv\%vmmmnv\%vn;;    mmmmnv\%vmmmmmm;;    nv\%vnmmv\%vnmmmv^\
     -| vmmnv\%vmmmmnv\%v;;      mmmnv\%vmmmmm;;      v\%vnmmmv\%vnmmmv^\
     -| vmmnv\%vmmmmnv\%vnmmmmmmmmm;;      mmmmmmmmmnv\%vnmmmmv\%vnmmmv^\
     -| vmmnv\%vmmmmnv\%vnmmmmmmmmmm;;    mmmmmmmmmmnv\%vnmmmmv\%vnmmmv^\
     -| vmmnv\%vmmmmnv\%vnmmmmmmmmmmnv;,mmmmmmmmmmmmnv\%vn;mmmv\%vnmmmv^\
     -| vmmnv\%vmmm. nv\%vnmmmmmmmmmnv\%;mmmmmmmmmmmnv\%vn; mmmv\%vnmmmv^\
     -| `vmmnv\%vmm,  v\%vnmmmmmmmmmmnv\%nmmmmmmmmmmnv\%v;  mmv\%vnnmmv'^\
     -|  vmmnv\%vmm;,   \%vnmmmmmmmmmnv\%nmmmmmmmmmnv\%;'   mv\%vnmmmmv^\
     -|   vmmnv\%vmm;;,   nmmm;'             mmmm;;'    mv\%vnmmmmv'^\
     -|   `vmmnv\%vmmm;;,.         mmnvv;,            mmv\%vnmmmmv'^\
     -|    `vmmnv\%vmmmmnv\%vnmmmmmmmmnvvnmmmmmmnv\%vnmmmv\%vnmmmmv'^\
     -|      `vmvn\%vmmmmnv\%vnmmmmmmmnvvnmmmmmnv\%vnmmmm\%vnmmmv'^\
     -|          `v\%mmmmmn%:\%vnmnmmmmn\%vnmmmnv%:\%vnmv\%nmv'
     -|
     -| ; A remarked line
     -|       ; Also a remarked line
     -| ;     A                          \
     -|       formatted and multi-line   \
     -|       remark


File: gcal.info,  Node: Comment line-Footnotes,  Up: Comment line

  (1) Physically and logically.


File: gcal.info,  Node: Include directives,  Next: Date variables,  Prev: Comment line,  Up: Resource file

Include directives
------------------

  You may add `#include' directives in a resource file for searching and
loading further resource files(1) (*note Include
directives-Footnote-1::).  An `#include' directive tells Gcal to
suspend reading the current resource file and read one other resource
file before continuing.  The directive is a line in the resource file
that looks like this template:

     #include _whitespace_ ARGUMENT [_whitespace_] _newline_

The ARGUMENT can either be

     "FILE NAME"

or(2) (*note Include directives-Footnote-2::)

     <FILE NAME>

  One _whitespace_ character minimum is required between `#include' and
the ARGUMENT.  The ARGUMENT may be trailed by extra _whitespace_
characters and the line must always end with a `\n' (newline)
character, except it is the last line of a resource file.

Let us inspect a example which is a bit more concrete:

  1. #include "foo/bar"

  2. #include <bar>

  The first `#include' directive tells Gcal to load the file `bar' in
the file directory `foo' from the actual file directory.  If this
fails, Gcal tries to load this file by using steps 1...4 of the
previously explained mechanism used for searching files (*note File
searching mechanism: x-File-searching-mechanism.).

  The second `#include' directive tells Gcal to load the file `bar'
from the user respectively system data file directory by using steps
3...4 of the previously explained mechanism used for searching files.
It is not allowed to include files which have a fixed access path
starting from the root file directory by such an `#include' directive
like `#include </file>' or `#include </foo/bar/file>'; just as the
specification of a single or an extended file name containing a
disk/drive specifier(3) (*note Include directives-Footnote-3::),
because the resulting path name(4) (*note Include
directives-Footnote-4::) would not be a valid file name any longer.

  Included files may include other files again.  But the nesting level
of included files is limited on the one hand by the amount of usable
working storage of the computer, and on the other hand by the value
which is given by the operating system respectively the compiler for
the number of files which can be opened simultaneously.  Recursive
includes(5) (*note Include directives-Footnote-5::) or cyclic
includes(6) (*note Include directives-Footnote-6::) are not permitted,
because such backward references would produce an infinite loop in the
program internally!  Gcal recognizes such situations and terminates
immediately with a fatal error.  *Note Error Code 119: x-119-Error-code,
for more information.

  If an included resource file cannot be found and no `--debug=abort'
option is given, processing of the resource file containing the
`#include' continues.


File: gcal.info,  Node: Include directives-Footnotes,  Up: Include directives

  (1) A mechanism similar the method which is used by the C
Preprocessor.

  (2) Thus, a file name which is embraced by `""' or `<>'.

  (3) Even if operating systems like MS-DOS or OS/2 permits such a
disk/drive specification on principle.

  (4) A path name lead by the user respectively system data file
directory name.

  (5) The included file tries to include itself again.

  (6) The included file is included again by another file that occurs
at a deeper place in such a chain.


File: gcal.info,  Node: Date variables,  Next: Text variables,  Prev: Include directives,  Up: Resource file

Date variables
--------------

  Gcal respects _global_ and/or _local_ date variables which may be
used either in the date part of a Gcal resource file line, or which may
be part of a special text in the text part of a Gcal resource file line.
This means, up to *24* user-defined date variables can be set and
referenced during program execution.  *Note Fixed date option
`--date-variable=ARGUMENT': x-date-variable, for more information how
global date variables can be used.

  A date variable name DVAR consists of a single, case-insensitive
letter(1) (*note Date variables-Footnote-1::).  In a definition, this
name is trailed by the assignment operator character `=', and the
numerical values of month MM (or a short, three characters month name,
e.g. `Jan', `Feb'...) and day DD, this variable has to store(2) (*note
Date variables-Footnote-2::), e.g.:

     a=1127
     c=a

stores the 27th November into the local date variable A and into the
local date variable C.  You should always remember that date variables
can only be referenced in a line if they are already defined, because
Gcal processes a resource file line by line.

  Only local date variables can store dynamical dates given in the
`MMWWWN', `DVAR[+|-]N[WWW]' or `*d|wN[WWW]' format, e.g.:

     a=03su2
     b=JunMon9
     c=b-3
     d=c+4Sa
     x=*d10
     y=*d10fri
     z=*w3Su

which means, date variable A stores the date of second Sunday in March
and B stores date of last Monday in June.  The date variable C stores
the date which is three days before the date of the last Monday in June
and this date is set in the date variable D to that date which is four
Saturdays after the date of C.  The date variable X stores the date of
the 10th absolute day of the year (== 10th January).  Y stores the date
of the 10th Friday of the year, and the assignment to Z is the date of
the Sunday which occurs in the 3rd week of the year.

*Caution:*
These kinds of assignments to date variables are *only* computed
correctly in simple year bounds --which means during a current year--
and not in fixed dates shown after the current year has changed, e.g.
in *fiscal years*.

  Date variables which are defined in a resource file are always local
and only respected in this specific file, and that file which is
included by it.  This means for the included file, that *all* local
variables of the caller are visible.  The included file itself may
define its own local variables in its own name-space, which are not
exported to caller on return.  All other definitions of date
variables(3) (*note Date variables-Footnote-3::) are always global.  If
a resource file line contains a reference to a date variable which is
not locally defined in that file, Gcal will try to use the global
values held by this variable.  If this fails because no global
definition of this date variable is given, Gcal will not process this
line.  If the simple `--debug' respectively `--debug=internal' option
is given, informational messages for each undefined date variable will
be shown on the _standard error channel_ (*note Global option
`--debug=internal': x-debug-internal.).  If the `--debug=abort' option
is given, the Gcal program will be aborted with an error code when the
first undefined global date variable reference occurs.  *Note Error
Code 113: x-113-Error-code, and *Note Global option `--debug=abort':
x-debug-abort, for further information.

  A local date variable can be deleted.  This means, that this date
variable is no longer valid in its local scope and be undefined
therefore.  So it is possible to use its potentially defined global
value in succeeding lines if this date variable is referenced there.
The following example of the resource file `dvar-1.rc' elucidates these
facts:

     $ cat dvar-1.rc
     -| ; dvar-1.rc
     -| ;
     -| z=0202
     -| 0@z The local assigned date to `z'
     -| z=
     -| 0@z The global assigned date to `z'
     -| z=0404
     -| 0@z The local assigned date to `z'

So Gcal creates the following output:

     $ gcal %1777 -H no -x -v z=1212 -f ./dvar-1.rc -y
     -|
     -| Sun, Feb   2nd 1777: The local assigned date to `z'
     -| Fri, Apr   4th 1777: The local assigned date to `z'
     -| Fri, Dec  12th 1777: The global assigned date to `z'
     $ gcal %1777 -H no -x -f ./dvar-1.rc -y
     -|
     -| Sun, Feb   2nd 1777: The local assigned date to `z'
     -| Fri, Apr   4th 1777: The local assigned date to `z'

  Only advanced users should apply the `--export-date-variables' option
which causes that the actual incarnation of a local date variable
--which was previously defined in a resource file and not in an
included file-- is being exported to further resource files instead of
using its global value, in case that date variable is not locally
defined in that further resource file.  *Note Include directives::, for
more details.

  But be aware, the use of this option could create unwanted results,
because the order of processing the resource files is an important
entity in managing the `--export-date-variables' option, so it is not
recommended to use it.  You, the user, must exactly know what you are
doing when applying this option; *you are expressively warned now!*

Some basic operations can be performed on date variables.  These are:

*Operation*    *Description*

`DVAR++'       Simple increment by one day.
`DVAR--'       Simple decrement by one day.
`DVAR+=[+|-]N' Addition of a constant numerical day factor [+|-]N.
`DVAR-=[+|-]N' Subtraction of a constant numerical day factor [+|-]N.
`DVAR+=NWWW'   Addition of N weekdays WWW.
`DVAR-=NWWW'   Subtraction of N weekdays WWW.

  The scope of the operations which are done on a local date variable,
is that resource or include file, where the local date variable is
defined.

  If operations on a global date variable are performed in a resource
file or that file which is included by it, these operations are only
valid in that specific file(4) (*note Date variables-Footnote-4::), not
in further resource files processed.  This means, the initial values of
global date variables are always restored if the resource file changes.

  Please finally note, that each date variable assignment/operation
must be given separately on a single line in the resource file.


File: gcal.info,  Node: Date variables-Footnotes,  Up: Date variables

  (1) Except the date variable E which is internally reserved for the
Easter Sunday's date, so it cannot be assigned or operated therefore.
And except the date variable T which is internally reserved for today's
date, so it likewise cannot be assigned or operated.

  (2) Or the name of another date variable, which is already defined.

  (3) In the command line, environment variable `GCAL' or response file.

  (4) They are only done locally.

