Merge pull request #3872 from stevengj/readwritable

add more isreadable/iswriteable/isreadonly functions

base/io.jl

@@ -22,6 +22,8 @@ else
     error("seriously? what is this machine?")
 end
 
+isreadonly(s) = isreadable(s) && !iswriteable(s)
+
 ## binary I/O ##
 
 # all subtypes should implement this
@@ -243,6 +245,8 @@ close(s::IOStream) = ccall(:ios_close, Void, (Ptr{Void},), s.ios)
 isopen(s::IOStream) = bool(ccall(:ios_isopen, Cint, (Ptr{Void},), s.ios))
 flush(s::IOStream) = ccall(:ios_flush, Void, (Ptr{Void},), s.ios)
 isreadonly(s::IOStream) = bool(ccall(:ios_get_readonly, Cint, (Ptr{Void},), s.ios))
+iswriteable(s::IOStream) = !isreadonly(s)
+isreadable(s::IOStream) = true
 
 truncate(s::IOStream, n::Integer) =
     (ccall(:ios_trunc, Int32, (Ptr{Void}, Uint), s.ios, n)==0 ||

base/iobuffer.jl

@@ -73,6 +73,9 @@ end
 
 read{T}(from::IOBuffer, ::Type{Ptr{T}}) = convert(Ptr{T}, read(from, Uint))
 
+isreadable(io::IOBuffer) = io.readable
+iswriteable(io::IOBuffer) = io.writable
+
 # TODO: IOBuffer is not iterable, so doesn't really have a length.
 # This should maybe be sizeof() instead.
 #length(io::IOBuffer) = (io.seekable ? io.size : nb_available(io))

base/stream.jl

@@ -177,6 +177,13 @@ function TTY(fd::RawFD; readable::Bool = false)
     ret
 end
 
+# note that uv_is_readable/writeable work for any subtype of
+# uv_stream_t, including uv_tty_t and uv_pipe_t
+isreadable(io::Union(NamedPipe,PipeServer,TTY)) =
+    bool(ccall(:uv_is_readable, Cint, (Ptr{Void},), io.handle))
+iswriteable(io::Union(NamedPipe,PipeServer,TTY)) =
+    bool(ccall(:uv_is_writable, Cint, (Ptr{Void},), io.handle))
+
 show(io::IO,stream::TTY) = print(io,"TTY(",uv_status_string(stream),", ",
     nb_available(stream.buffer)," bytes waiting)")