Re: Redirecting XS stdout

You shouldn't be using C IO lib, you should be using Perl's. (Well, I think so at least. I have no experience in this area.)

Update: Yup, that does the trick:

void c_output() {
    PerlIO_printf(PerlIO_stdout(), "###c_output");
}
void c_output_newline() {
    PerlIO_printf(PerlIO_stdout(), "###c_output_newline\n");
}
[download]

>set PERLIO=stdio

>perl a.pl
===============dry run============
        printing [perl_output_newline]
***perl_output_newline
        calling  [c_output_newline]
###c_output_newline
        printing [perl_output]
***perl_output  calling  [c_output]
###c_output
=============test_global==========
        printing [perl_output_newline]
        calling  [c_output_newline]
        printing [perl_output]
        calling  [c_output]
test_global buffer:
(***perl_output_newline\n###c_output_newline\n***perl_output###c_outpu
+t)


>set PERLIO=perlio

>perl a.pl
===============dry run============
        printing [perl_output_newline]
***perl_output_newline
        calling  [c_output_newline]
###c_output_newline
        printing [perl_output]
        calling  [c_output]
***perl_output###c_output
=============test_global==========
        printing [perl_output_newline]
        calling  [c_output_newline]
        printing [perl_output]
        calling  [c_output]
test_global buffer:
(***perl_output_newline\n###c_output_newline\n***perl_output###c_outpu
+t)
[download]

Comment on Re: Redirecting XS stdout Select or Download Code

Replies are listed 'Best First'.
Re^2: Redirecting XS stdout by Anonymous Monk on Feb 21, 2010 at 01:12 UTC
perlclib has a nice list of Internal replacements for standard C library functions	[reply]
Re^2: Redirecting XS stdout by innominate (Beadle) on Feb 21, 2010 at 05:33 UTC
++ You know what, that's just the key I needed! I'm trying to wrap some C with as little modification as possible (staying current with the upstream). I didn't want to replace any IO calls directly, but after seeing your PerlIO call it dawned on me to simply override the stdio calls with PerlIO. `#define fprintf(fh,...) PerlIO_printf(fh,__VA_ARGS__); #define stdout PerlIO_stdout() #define stderr PerlIO_stderr()` [download] Thanks!	[reply] [d/l]
Re^3: Redirecting XS stdout by ikegami (Patriarch) on Feb 21, 2010 at 06:18 UTC
Exactly. You'd think something like this already exists. Maybe it does. (Google code search?)	[reply]
Re^4: Redirecting XS stdout by cdarke (Prior) on Feb 21, 2010 at 08:24 UTC
Maybe it does fakesdio.h It is part of the base perl source code. See also perlsdio.h.	[reply]
Re^4: Redirecting XS stdout by innominate (Beadle) on Feb 21, 2010 at 08:18 UTC
I think I've figured out why I didn't stumble on this method before.. After redefining the macros, I discovered the code I'm wrapping is taking the "return early, return often" concept to the extreme by way of exits. Oh well, back to the drawing board! Thanks again :)	[reply]