You are correct,
julia> open("foo" ,"w") do file
libcf = Libc.FILE(file)
ccall(:fprintf, Int, (Ptr{Void}, Cstring), libcf.ptr, "hello,
world\n")
display(readstring("foo"))
close(libcf)
display(readstring("foo"))
end
""
"hello, world\n"
julia>
On Wednesday, March 9, 2016 at 5:43:06 PM UTC-6, Erik Schnetter wrote:
>
> I assume that `Libc.FILE(foo)` creates a new file descriptor that is
> independent of `file`, and which needs to be closed as well.
>
> -erik
>
> On Wed, Mar 9, 2016 at 3:07 PM, Samuel Massinon
> <[email protected] <javascript:>> wrote:
> > Tried looking for a solution but couldn't find anything. If I'm doing
> > anything wrong please let me know. :)
> >
> > If I run the following,
> > foo = open("foo" ,"w")
> > ccall(:fprintf, Int, (Ptr{Void}, Cstring), Libc.FILE(foo).ptr, "hello,
> > world\n")
> > flush(foo)
> > close(foo)
> > foo will exists as a file in my current directory, but will not contain
> > "hello, world\n", only when I exit julia will it write to foo.
> >
> > When I add
> > ccall(:fflush, Int, (Ptr{Void},), C_NULL)
> > at the end, then foo will contain "hello, world\n".
> >
> > Here's the example output.
> > samuelmassinon ~$ cat foo
> > cat: foo: No such file or directory
> > samuelmassinon ~$ julia
> > _
> > _ _ _(_)_ | A fresh approach to technical computing
> > (_) | (_) (_) | Documentation: http://docs.julialang.org
> > _ _ _| |_ __ _ | Type "?help" for help.
> > | | | | | | |/ _` | |
> > | | |_| | | | (_| | | Version 0.5.0-dev+3075 (2016-03-09 17:54 UTC)
> > _/ |\__'_|_|_|\__'_| | Commit 597dc7b (0 days old master)
> > |__/ | x86_64-apple-darwin15.2.0
> >
> > julia> foo = open("foo" ,"w")
> > IOStream(<file foo>)
> >
> > julia> ccall(:fprintf, Int, (Ptr{Void}, Cstring), Libc.FILE(foo).ptr,
> > "hello, world\n")
> > 13
> >
> > julia> flush(foo)
> > IOStream(<file foo>)
> >
> > julia> close(foo)
> >
> > shell> cat foo
> >
> > julia> exit()
> > samuelmassinon ~$ cat foo
> > hello, world
> >
> >
> > I don't think I should have to use fflush to write to a file from c. Is
> > there a better way of doing this that isn't hacky?
> >
> > Thanks!
>
>
>
> --
> Erik Schnetter <[email protected] <javascript:>>
> http://www.perimeterinstitute.ca/personal/eschnetter/
>
