First of all, a Gcal resource file is a plain ASCII text file. This text file may be created by any text editor or by redirecting the standard output channel to a file, e.g.:
$ echo '19930217 Text'>> resource-file RET
A special —but simple— line structure is required so Gcal is able to interpret its contents. Each fixed date entry in a resource file must be split into two parts, namely a date part and an optional text part which must be separated by one whitespace42 character minimum. It is unnecessary to give a whitespace separator character if no text part is specified.
A line must always end with a ‘\n’ (newline) character, except it is the
last line of a resource file. The maximum length of a line is limited to
INT_MAX43 characters. A newline character is
automatically appended to the line if the standard output channel is
directed to a file. A newline character is appended to the typed line in a
text editor window if it is completed by pressing the RET key. In case
the used text editor does not generate the newline character in this way, it
should be set to this mode of operation, otherwise this text editor is useless
for creating Gcal resource files.
The line structure of fixed date entries is:
date part [ whitespace text part ] newline
or more concrete, e.g.:
yyyy[mm[dd|wwwn]] [ whitespace text ] newline
or much more concrete, e.g.:
19940217 Hi, I'm the text!
Besides fixed date entries, a resource file may contain further entries like:
; A remarked line ; A formatted and multi-line \ remark
#include <file name> #include "file name"
Date variable assignments respectively operations…
dvar=NOTHING dvar=mmdd dvar=mmwwwn dvar=*dn[www] dvar=*wn[www] dvar=dvar[[+|-]n[www]] dvar++ dvar-- dvar+=[+|-]n dvar-=[+|-]n dvar+=nwww dvar-=nwww
Text variable assignments respectively operations…
tvar=[text] tvar?[command] tvar:[command] tvar++ tvar-- tvar+=[+|-]n tvar-=[+|-]n
Text variable references…
Text variable references at the beginning of a Gcal resource file line may only be used if it is ensured that they are expanded to a valid Gcal resource file line.