[tcljava-dev] Jacl and file mtime

[<cs...@ma...>]

Hi!

I am using the Java implementation of Tcl, called Jacl, version 1.2.6.

I just tried to use the "file mtime <filename>" command and found out that
it does not work properly (on Windows 95/NT, that is). The reason seems to
be that the Tcl concept of integers is 32-bit and that the Java
File.getModified() method returns a long too long to be stored in an int.
By experimenting with  File.getModified() in pure Java (on Windows 95) I
found out that the three rigtmost digits of this huge number always were
"000". So, by fixing tcl.lang.FileCmd's method getMtime() to return the
time / 1000, "file mtime" became acceptable for an int - and it became
useful, e.g. for "make" like utilities.

Recap: In tcl.lang.FileCmd, method getMtime(), I changed:

  return (int) fileObj.lastModified();

to something like:

  long l = fileObj.lastModified();
  return (int) (l / 1000);

I should stress that I this was tested on Windows 95, where I get that long
(12 decimal digits) result but always with "000" in the rightmost three
digits. On Windows NT 4, I get a similarly long number but actually the
three rightmost digits are not (always) "000". But maybe the granularity is
so fine here that my simple fix still would work for all practical
purposes. From Windows NT, I have two files with the same timestamp
(<hours>:<minutes>), i.e. same minute, and they are different from the 5'th
digit from the right, not bad:

978591035662
978591042491

By the way: This "97" indicates that soon (?) we should be able to handle
13 digits!!?

What happens on non-Windows platforms I don't know.

I considered introducing the Java type "long" in Jacl but that seems hard
to control and a violation of some nice and simple principles for Tcl per
se.

Kind regards, Christian Sorensen.