Öznur Taþtan wrote: > Hi, > I am trying to use struct as an argument of a function. > In the piece of code I try to use $t as a parameter of the print_usage function but > it gives the error: > > Can't call method "ru_stime" without a package or object reference at str.txt l > ne 28. > > Could anyone explain what is wrong?
Specifically? This: [EMAIL PROTECTED]; You have just assigned an integer [the count of elements in the parameter list] to $r print $r->ru_stime->tv_secs; Here you have tried to reference the ru_stime member of an integer. In general, I see a conceptual problem here. What does "r" tell you about the intended usage of the variable? Or "t"? [I will grant that the use of t as an abbreviation for time is very common, but three extra characters do not cost that much for the time saved in understanding and debugging the code.] Perl can support very natural styles of coding. If you are going to use Perl, you should make use of that feature, Actually, C does also. From the start, C compilers offered support for a minimum of 32 significant characters in identifiers. C programmers just failed to make good use of this. Perl offers even more flexibility. Cryptic, everything-is-an-abbreviation coding style is a relic of a not-so-long-ago time when hardware resources were expensive, and editing facilities primitive. Please let it pass away along with the ill-fated 20th Century. [Escuse me if I'm going on a bit long here. I'm in the process of installing the module you are using, which has necessitated the force install of the package: ftp://archive.progeny.com/CPAN/authors/id/N/NW/NWCLARK/perl-5.8.3.tar.gz, which sounds like a [possibly incompatible] upgrade to Perl itself. It is taking awhile.... Hooboy, thar they come... and they's a whole s---load o' files, thar, matey! ... CPAN.pm: Going to build N/NW/NWCLARK/perl-5.8.3.tar.gz Program too big to fit in memory] That's OK. the perldoc utility still runs, so we can see what kind of animal we're working with. > > thanks > oznur > > use Class::Struct; > > struct( rusage => { > ru_utime => timeval, # seconds > ru_stime => timeval, # microseconds > }); Is there a timeval class? The values for these pairs ...yacketty-yack... > struct( timeval => [ > tv_secs => '$', > tv_usecs => '$', > ]); Oh, now I see. Unfortunately, the compiler, reading in the same direction as I, probably does not get here. This should be defined above, or in a package called with use. Files are also cheap. There is no extra price to maling a discrete package file for each struct. This will also allow for more flexible use of each struct/class/package you design. > my $t = new rusage; > > > $t->ru_utime->tv_secs(100); > $t->ru_utime->tv_usecs(0); > $t->ru_stime->tv_secs(5); > $t->ru_stime->tv_usecs(0); > > > &print_rusage($t); Don't do this. The & operator is needed only in special cicumstances > > > sub print_rusage{ > my $r=new rusage; > [EMAIL PROTECTED]; > print $r->ru_stime->tv_secs; > } I think I asnwered your immediate issue in the first paragraph of my response. I wish I could offer more assistance, but I have no idea what "ru_" or "tv_" or "usecs" as opposed to "secs" would mean. This puts me, other helpers, and you, reviewing the code a month or a year later, at a great disadvantage. Can you try substituting some more descriptive identifiers, and repost? Most editors have "Replace all" features that can make such substitutions very easy. Frankly, I don't see why you are doing this. C structs are excellent tools--for use within the C programming paradigm. They are really something of a misfit in Perl. They have to be superimposed on structures that already are built, internally, on C structs. The Perl hash or package will serve the functions of a C struct wonderfully, with only a small paradigm shift. I would really recommend that you get familiar with Perl hashes and objects first, and exploit the native capabilities they offer, before trying to import programming structures from outside the language. For compatibility with C, you might want to look into the XS interface. This is the standard Perl interface for connecting with C code. Generally, though, unless you are doing highly cumputational work, native Perl functionality will serve quite well. Joseph -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] <http://learn.perl.org/> <http://learn.perl.org/first-response>
