Re: How *do* they do that?


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Re: How do they do that?

by abstracts (Hermit)

on Aug 12, 2001 at 13:56 UTC ( [id://104222]=note: print w/replies, xml )

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in reply to How does Perl handle opendir/readdir/closedir internally?

Hello

If you look at the opendir(3) manpage, you will see that perl's opendir, readdir and closedir are handled directly by their C counterparts. The DIR * data type is defined I believe in dirent.h or in sys/types.h.

I believe implementing opendir, readdir and closedir are straightforward in XS given that this is their calling syntax:

DIR *opendir(const char *name);
int closedir(DIR *dir);
struct dirent *readdir(DIR *dir);
[download]

Did I answer the question?

Aziz,,,

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Re: Re: How *do* they do that?
by gellyfish (Monsignor) on Aug 12, 2001 at 17:20 UTC

In an XS program it appears that it is slightly more complicated than this as the XSUB.h for perl 5.72 has :


   #    define opendir             PerlDir_open
[download]

PerlDir_open itself is defined in iperlsys.h in 5.72 - this is so that it can be made to fit in with the whole PerlIO thing.

Probably the easiest way of finding out what is going on in here is to look at the implementation of pp_open_dir in pp_sys.c and then work backward from there.