KNX LogicMachine3 Re:actor, Product Manual

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When called without arguments, date returns a reasonable date and time representation that
depends on the host system and on the current locale (that is,
os.date()
is equivalent to
os.date("%c")).
os.difftime (t2, t1)
Returns the number of seconds from time t1 to time t2. In POSIX, Windows, and some other
systems, this value is exactly t2-t1.
os.execute ([command])
This function is equivalent to the C function system. It passes command to be executed by an
operating system shell. It returns a status code, which is system-dependent. If command is
absent, then it returns nonzero if a shell is available and zero otherwise.
os.exit ([code])
Calls the C function exit, with an optional code, to terminate the host program. The default value
for code is the success code.
os.getenv (varname)
Returns the value of the process environment variable varname, or
nil
if the variable is not
defined.
os.remove (filename)
Deletes the file or directory with the given name. Directories must be empty to be removed. If
this function fails, it returns nil, plus a string describing the error.
os.rename (oldname, newname)
Renames file or directory named oldname to newname. If this function fails, it returns nil , plus a
string describing the error.
os.time ([table])
Returns the current time when called without arguments, or a time representing the date and time
specified by the given table. This table must have fields year, month, and day, and may have
fields hour, min, sec, and
isdst
(for a description of these fields, see the
os.date
function).
The returned value is a number, whose meaning depends on your system. In POSIX, Windows,
and some other systems, this number counts the number of seconds since some given start time
(the "epoch"). In other systems, the meaning is not specified, and the number returned by time
can be used only as an argument to date and
difftime
.
os.tmpname ()
Returns a string with a file name that can be used for a temporary file. The file must be explicitly
opened before its use and explicitly removed when no longer needed. On some systems
(POSIX), this function also creates a file with that name, to avoid security risks. (Someone
else might create the file with wrong permissions in the time between getting the name and
creating the file.) You still have to open the file to use it and to remove it (even if you do not use
it).
When possible, you may prefer to use
io.tmpfile
, which automatically removes the file when the
program
ends.