IO

📦 std

Load the core IO modules — IO::Handle, IO::File, IO::Seekable, IO::Pipe, IO::Socket, IO::Dir — in one use.

This is the bootstrap module that IO::Handle, IO::File, IO::Seekable, IO::Dir, IO::Socket, IO::Pipe all depend on. Without it, require IO fails with “dynamic loading not available”.

Functions are registered in their respective packages (IO::Seekable::, IO::File::, IO::Handle::, IO::Socket::) — NOT in IO:: itself.

The BOOT section installs numeric constants into IO::Poll:: and IO::Handle:: stashes via newCONSTSUB.

Functions

Other Functions

io_import

IO.xs: MODULE = IO — import is a no-op at the XS level. The Perl-level IO.pm does eval "require IO::$_" for each arg.

fgetpos

IO.xs:149-173 fgetpos(handle) PerlIO path: RETVAL = newSV(0); PerlIO_getpos(handle, RETVAL) On failure or null handle: returns &PL_sv_undef.

fsetpos

IO.xs:176-201 fsetpos(handle, pos) Returns 0 on success, -1 on failure.

new_tmpfile

IO.xs:205-230 new_tmpfile(packname = “IO::File”) Creates a PerlIO tmpfile, wraps in a new GV, do_open with “+>&”, blesses the RV into packname. Returns blessed ref or undef.

io_blocking

IO.xs:267-281 io_blocking(handle, blk=-1) XS wrapper: calls io_blocking_impl, returns IV or undef.

ungetc

IO.xs:286-325 ungetc(handle, c) Simplified: we handle the PerlIO path only (no stdio fallback). skipped: UTF-8 multi-byte ungetc path (UVCHR_IS_INVARIANT / Perl_PerlIO_isutf8 / uvchr_to_utf8_flags) — would need full UTF-8 encoding machinery. For now we handle the single-byte invariant case which covers ASCII and the non-utf8-handle path.

ferror

IO.xs:327-346 ferror(handle) Returns Perl_PerlIO_error(in) || (out && in != out && Perl_PerlIO_error(out)).

clearerr

IO.xs:348-373 clearerr(handle) Clears error on both input and output streams. Returns 0 or -1.

untaint

IO.xs:375-394 untaint(handle) No-op in our runtime (taint not supported). Returns 0 if handle valid, -1 otherwise. IO.xs sets IoFLAGS(io) |= IOf_UNTAINT — we just return 0.

fflush

IO.xs:396-411 fflush(handle) Returns 0 on success, -1 on error.

setbuf

IO.xs:413-426 setbuf(handle, …) Non-PERLIO_IS_STDIO path: not_here(”IO::Handle::setbuf”) With PerlIO (our case): if buf is undef, call Perl_PerlIO_setlinebuf. IO.xs only implements this for PERLIO_IS_STDIO; for PerlIO it calls not_here. We implement the Perl_PerlIO_setlinebuf path when buf is undef (common usage), and croak for the PERLIO_IS_STDIO setbuf case.

setvbuf

IO.xs:428-458 setvbuf(handle, buf, type, size) Only available under PERLIO_IS_STDIO && _IOFBF && HAS_SETVBUF. We are PerlIO (not PERLIO_IS_STDIO), so this croaks.

fsync

IO.xs:462-492 fsync(arg) Calls fsync(Perl_PerlIO_fileno(handle)).

getlines

IO.xs:520-565 getlines(…) / getline / gets These call pp_readline internally. For our implementation: getlines (ix=0): reads all lines in list context, croaks in scalar context. getline/gets (ix=1,2): reads one line in scalar context.

getlines_common

Common implementation for getlines/getline/gets. ix=0 → getlines (list context, croak if scalar) ix=1 → getline/gets (scalar context)

sockatmark

IO.xs:567-602 sockatmark(sock) Uses SIOCATMARK ioctl on Linux (HAS_SOCKATMARK path uses sockatmark(3), but ioctl is the fallback and what Linux actually does).