diff options
Diffstat (limited to 'pod/perliol.pod')
| -rw-r--r-- | pod/perliol.pod | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/pod/perliol.pod b/pod/perliol.pod index b4c8069723..81cbab17e7 100644 --- a/pod/perliol.pod +++ b/pod/perliol.pod @@ -98,6 +98,7 @@ same as the public C<PerlIO_xxxxx> functions: int fd, int imode, int perm, PerlIO *old, int narg, SV **args); + IV (*Binmode)(pTHX_ PerlIO *f); SV * (*Getarg)(pTHX_ PerlIO *f, CLONE_PARAMS *param, int flags) IV (*Fileno)(pTHX_ PerlIO *f); PerlIO * (*Dup)(pTHX_ PerlIO *f, PerlIO *o, CLONE_PARAMS *param, int flags) @@ -346,24 +347,31 @@ The size of the per-instance data structure, e.g.: IV kind; - XXX: explain all the available flags here - =over 4 =item * PERLIO_K_BUFFERED +The layer is buffered. + +=item * PERLIO_K_RAW + +The layer is acceptable to have in a binmode(FH) stack - i.e. it does not +(or will configure itself not to) transform bytes passing through it. + =item * PERLIO_K_CANCRLF +Layer can translate between "\n" and CRLF line ends. + =item * PERLIO_K_FASTGETS +Layer allows buffer snooping. + =item * PERLIO_K_MULTIARG Used when the layer's open() accepts more arguments than usual. The extra arguments should come not before the C<MODE> argument. When this flag is used it's up to the layer to validate the args. -=item * PERLIO_K_RAW - =back =item Pushed @@ -455,6 +463,16 @@ then push itself on top if that succeeds. Returns C<NULL> on failure. +=item Binmode + + IV (*Binmode)(pTHX_ PerlIO *f); + +Optional. Used when C<:raw> layer is pushed (explicitly or as a result +of binmode(FH)). If not present layer will be popped. If present +should configure layer as binary (or pop itself) and return 0. +If it returns -1 for error C<binmode> will fail with layer +still on the stack. + =item Getarg SV * (*Getarg)(pTHX_ PerlIO *f, @@ -700,8 +718,11 @@ and so resumes reading from layer below.) =item "raw" A dummy layer which never exists on the layer stack. Instead when -"pushed" it actually pops the stack(!), removing itself, and any other -layers until it reaches a layer with the class C<PERLIO_K_RAW> bit set. +"pushed" it actually pops the stack removing itself, it then calls +Binmode function table entry on all the layers in the stack - normally +this (via PerlIOBase_binmode) removes any layers which do not have +C<PERLIO_K_RAW> bit set. Layers can modify that behaviour by defining +their own Binmode entry. =item "utf8" |