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Diffstat (limited to 'gnu/usr.bin/perl/pod/perliol.pod')
| -rw-r--r-- | gnu/usr.bin/perl/pod/perliol.pod | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/gnu/usr.bin/perl/pod/perliol.pod b/gnu/usr.bin/perl/pod/perliol.pod index 55aaf147f7f..b70a510aadd 100644 --- a/gnu/usr.bin/perl/pod/perliol.pod +++ b/gnu/usr.bin/perl/pod/perliol.pod @@ -505,6 +505,14 @@ arguments passed to them, I<n> is the index into that array of the layer being called. The macro C<PerlIOArg> will return a (possibly C<NULL>) SV * for the argument passed to the layer. +Where a layer opens or takes ownership of a file descriptor, that layer is +responsible for getting the file descriptor's close-on-exec flag into the +correct state. The flag should be clear for a file descriptor numbered +less than or equal to C<PL_maxsysfd>, and set for any file descriptor +numbered higher. For thread safety, when a layer opens a new file +descriptor it should if possible open it with the close-on-exec flag +initially set. + The I<mode> string is an "C<fopen()>-like" string which would match the regular expression C</^[I#]?[rwa]\+?[bt]?$/>. @@ -525,6 +533,9 @@ If I<fd> not negative then it is the numeric file descriptor I<fd>, which will be open in a manner compatible with the supplied mode string, the call is thus equivalent to C<PerlIO_fdopen>. In this case I<nargs> will be zero. +The file descriptor may have the close-on-exec flag either set or clear; +it is the responsibility of the layer that takes ownership of it to get +the flag into the correct state. If I<nargs> is greater than zero then it gives the number of arguments passed to C<open>, otherwise it will be 1 if for example |