=over 4
-=item char * name;
+=item name
+
+ char * name;
The name of the layer whose open() method Perl should invoke on
open(). For example if the layer is called APR, you will call:
and Perl knows that it has to invoke the PerlIOAPR_open() method
implemented by the APR layer.
-=item Size_t size;
+=item size
+
+ Size_t size;
The size of the per-instance data structure, e.g.:
sizeof(PerlIOAPR)
-=item IV kind;
+=item kind
+
+ IV kind;
XXX: explain all the available flags here
=back
-=item IV (*Pushed)(pTHX_ PerlIO *f,const char *mode, SV *arg);
+=item Pushed
+
+ IV (*Pushed)(pTHX_ PerlIO *f,const char *mode, SV *arg);
The only absolutely mandatory method. Called when the layer is pushed
onto the stack. The C<mode> argument may be NULL if this occurs
Returns 0 on success. On failure returns -1 and should set errno.
-=item IV (*Popped)(pTHX_ PerlIO *f);
+=item Popped
+
+ IV (*Popped)(pTHX_ PerlIO *f);
Called when the layer is popped from the stack. A layer will normally
be popped after C<Close()> is called. But a layer can be popped
Returns 0 on success and failure.
-=item PerlIO * (*Open)(...);
+=item Open
+
+ PerlIO * (*Open)(...);
The C<Open()> method has lots of arguments because it combines the
functions of perl's C<open>, C<PerlIO_open>, perl's C<sysopen>,
Returns C<NULL> on failure.
-=item SV * (*Getarg)(pTHX_ PerlIO *f, CLONE_PARAMS *param, int flags)
+=item Getarg
+
+ SV * (*Getarg)(pTHX_ PerlIO *f,
+ CLONE_PARAMS *param, int flags);
Optional. If present should return an SV * representing the string
argument passed to the layer when it was
"ascii". (I<param> and I<flags> arguments can be ignored in most
cases)
-=item IV (*Fileno)(pTHX_ PerlIO *f);
+=item Fileno
+
+ IV (*Fileno)(pTHX_ PerlIO *f);
Returns the Unix/Posix numeric file descriptor for the handle. Normally
C<PerlIOBase_fileno()> (which just asks next layer down) will suffice
XXX: two possible results end up in -1, one is an error the other is
not.
-=item PerlIO * (*Dup)(pTHX_ PerlIO *f, PerlIO *o, CLONE_PARAMS *param, int flags)
+=item Dup
+
+ PerlIO * (*Dup)(pTHX_ PerlIO *f, PerlIO *o,
+ CLONE_PARAMS *param, int flags);
XXX: not documented
Similar to C<Open>, returns PerlIO* on success, C<NULL> on failure.
-=item SSize_t (*Read)(pTHX_ PerlIO *f, void *vbuf, Size_t count);
+=item Read
+
+ SSize_t (*Read)(pTHX_ PerlIO *f, void *vbuf, Size_t count);
Basic read operation.
Returns actual bytes read, or -1 on an error.
-=item SSize_t (*Unread)(pTHX_ PerlIO *f, const void *vbuf, Size_t count);
+=item Unread
+
+ SSize_t (*Unread)(pTHX_ PerlIO *f,
+ const void *vbuf, Size_t count);
A superset of stdio's C<ungetc()>. Should arrange for future reads to
see the bytes in C<vbuf>. If there is no obviously better implementation
Returns the number of unread chars.
-=item SSize_t (*Write)(PerlIO *f, const void *vbuf, Size_t count);
+=item Write
+
+ SSize_t (*Write)(PerlIO *f, const void *vbuf, Size_t count);
Basic write operation.
Returns bytes written or -1 on an error.
-=item IV (*Seek)(pTHX_ PerlIO *f, Off_t offset, int whence);
+=item Seek
+
+ IV (*Seek)(pTHX_ PerlIO *f, Off_t offset, int whence);
Position the file pointer. Should normally call its own C<Flush>
method and then the C<Seek> method of next layer down.
Returns 0 on success, -1 on failure.
-=item Off_t (*Tell)(pTHX_ PerlIO *f);
+=item Tell
+
+ Off_t (*Tell)(pTHX_ PerlIO *f);
Return the file pointer. May be based on layers cached concept of
position to avoid overhead.
Returns -1 on failure to get the file pointer.
-=item IV (*Close)(pTHX_ PerlIO *f);
+=item Close
+
+ IV (*Close)(pTHX_ PerlIO *f);
Close the stream. Should normally call C<PerlIOBase_close()> to flush
itself and close layers below, and then deallocate any data structures
Returns 0 on success, -1 on failure.
-=item IV (*Flush)(pTHX_ PerlIO *f);
+=item Flush
+
+ IV (*Flush)(pTHX_ PerlIO *f);
Should make stream's state consistent with layers below. That is, any
buffered write data should be written, and file position of lower layers
Returns 0 on success, -1 on failure.
-=item IV (*Fill)(pTHX_ PerlIO *f);
+=item Fill
+
+ IV (*Fill)(pTHX_ PerlIO *f);
The buffer for this layer should be filled (for read) from layer
below. When you "subclass" PerlIOBuf layer, you want to use its
Returns 0 on success, -1 on failure.
-=item IV (*Eof)(pTHX_ PerlIO *f);
+=item Eof
+
+ IV (*Eof)(pTHX_ PerlIO *f);
Return end-of-file indicator. C<PerlIOBase_eof()> is normally sufficient.
Returns 0 on end-of-file, 1 if not end-of-file, -1 on error.
-=item IV (*Error)(pTHX_ PerlIO *f);
+=item Error
+
+ IV (*Error)(pTHX_ PerlIO *f);
Return error indicator. C<PerlIOBase_error()> is normally sufficient.
Returns 1 if there is an error (usually when C<PERLIO_F_ERROR> is set,
0 otherwise.
-=item void (*Clearerr)(pTHX_ PerlIO *f);
+=item Clearerr
+
+ void (*Clearerr)(pTHX_ PerlIO *f);
Clear end-of-file and error indicators. Should call C<PerlIOBase_clearerr()>
to set the C<PERLIO_F_XXXXX> flags, which may suffice.
-=item void (*Setlinebuf)(pTHX_ PerlIO *f);
+=item Setlinebuf
+
+ void (*Setlinebuf)(pTHX_ PerlIO *f);
Mark the stream as line buffered. C<PerlIOBase_setlinebuf()> sets the
PERLIO_F_LINEBUF flag and is normally sufficient.
-=item STDCHAR * (*Get_base)(pTHX_ PerlIO *f);
+=item Get_base
+
+ STDCHAR * (*Get_base)(pTHX_ PerlIO *f);
Allocate (if not already done so) the read buffer for this layer and
return pointer to it. Return NULL on failure.
-=item Size_t (*Get_bufsiz)(pTHX_ PerlIO *f);
+=item Get_bufsiz
+
+ Size_t (*Get_bufsiz)(pTHX_ PerlIO *f);
Return the number of bytes that last C<Fill()> put in the buffer.
-=item STDCHAR * (*Get_ptr)(pTHX_ PerlIO *f);
+=item Get_ptr
+
+ STDCHAR * (*Get_ptr)(pTHX_ PerlIO *f);
Return the current read pointer relative to this layer's buffer.
-=item SSize_t (*Get_cnt)(pTHX_ PerlIO *f);
+=item Get_cnt
+
+ SSize_t (*Get_cnt)(pTHX_ PerlIO *f);
Return the number of bytes left to be read in the current buffer.
-=item void (*Set_ptrcnt)(pTHX_ PerlIO *f,STDCHAR *ptr,SSize_t cnt);
+=item Set_ptrcnt
+
+ void (*Set_ptrcnt)(pTHX_ PerlIO *f,
+ STDCHAR *ptr, SSize_t cnt);
Adjust the read pointer and count of bytes to match C<ptr> and/or C<cnt>.
The application (or layer above) must ensure they are consistent.
projects / p5sagit/p5-mst-13.2.git / blobdiff