From d33298e52459045ddde4bae619a8da3c3cf7dbd6 Mon Sep 17 00:00:00 2001 From: matz Date: Mon, 29 Dec 2008 09:07:20 +0000 Subject: * ext/io/wait/wait.c (io_nread): returns number of bytes available for read. response to feature request #936 in [ruby-core:20917]. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@21169 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- ext/io/wait/wait.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'ext/io/wait') diff --git a/ext/io/wait/wait.c b/ext/io/wait/wait.c index 24e4141162..b73c9af1ce 100644 --- a/ext/io/wait/wait.c +++ b/ext/io/wait/wait.c @@ -42,6 +42,31 @@ void Init_wait _((void)); EXTERN struct timeval rb_time_interval _((VALUE time)); +/* + * call-seq: + * io.nread -> int + * + * Returns number of bytes that can be read without blocking. + * Returns zero if no information available. + */ + +static VALUE +io_nread(VALUE io) +{ + rb_io_t *fptr; + int len; + ioctl_arg n; + + GetOpenFile(io, fptr); + rb_io_check_readable(fptr); + len = rb_io_read_pending(fptr); + if (len > 0) return len; + if (!FIONREAD_POSSIBLE_P(fptr->fd)) return INT2FIX(0); + if (ioctl(fptr->fd, FIONREAD, &n)) return INT2FIX(0); + if (n > 0) return ioctl_arg2num(n); + return INT2FIX(0); +} + /* * call-seq: * io.ready? -> true, false or nil @@ -137,6 +162,7 @@ io_wait(int argc, VALUE *argv, VALUE io) void Init_wait() { + rb_define_method(rb_cIO, "nread", io_nread, 0); rb_define_method(rb_cIO, "ready?", io_ready_p, 0); rb_define_method(rb_cIO, "wait", io_wait, -1); } -- cgit v1.2.3