Re^2: Calling strace -f

I tried commenting out that line, and I get:

...
ioctl(0, SNDCTL_TMR_TIMEBASE or TCGETS, 0xbf99e438) = -1 EINVAL (Inval
+id argument)
fstat64(0, {st_mode=S_IFIFO|0600, st_size=0, ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
+ 0) = 0xb7b62000
read(0, "load(\'jslint.js\');\nfoo=0;\nEND\nqu"..., 1024) = 38
read(0,
[download]

So, it's not even to the point where it's processing the information coming from perl. It hasn't even loaded jslint.js yet. I think I get it. So let's see if I'm understanding this properly:

While perl may be properly autoflushing, the interpreter is still buffering its read. Since the socket(?) is still open, it doesn't know to close it and flush.

When it does close it and flush, it is acutally waiting to make use of the rest of the string ("foo=0;\nEND\n") AFTER the readline loop. So it would be as if I had done something like this (which also freezes):

$ echo -e "load('jslint.js');\nfoo=0;\nEND\n" |/usr/bin/js
[download]

Hence, the rock and hard place are that, if I don't close $JSWRITE in a timely manner, the interpreter won't know to flush its read buffer and continue, but if I do close $JSWRITE, there's nothing for the readline() loop to read from anymore.

So it's not so much that my Perl code isn't outputting correctly, it's that the interpreter is accepting/buffering input in an incompatible way?

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Re^3: Calling strace -f by almut (Canon) on Nov 19, 2008 at 22:26 UTC
if I don't close $JSWRITE in a timely manner, the interpreter won't know to flush its read buffer and continue, but if I do close $JSWRITE, there's nothing for the readline() loop to read from anymore. I think you nailed it.	[reply]
Re^3: Calling strace -f by ikegami (Patriarch) on Nov 20, 2008 at 01:58 UTC
Update: Ignore this post. I misunderstood the issue Buy why is it calling `close(0)`? And why is it different when it's connected to a terminal? SIGPIPE? I see three possible solutions: Fooling it into thinking its talking to a terminal. Sending `"\n"x4096` after `"END"`. Maing `js` read from a file, not from a pipe.	[reply] [d/l] [select]
Re^3: Calling strace -f by ikegami (Patriarch) on Nov 20, 2008 at 02:25 UTC
So the solution is to not read from STDIN. Pass a file name instead of the file contents. Read more... to_js_str_literal (846 Bytes) `my $js_script_qfn = to_js_str_literal($script_qfn); print $JSWRITE <<"__END__"; var filename = $js_script_qfn; load('jslint.js'); END __END__` [download] Well, don't know if scoping allows that exactly, but you get the idea. Update: I suppose you could pass the file contents in the same manner. `print $JSWRITE map "$_\n", "var file = [", ( map " ".to_js_str_literal($_), <$fh> ), "];", "load('jslint.js');", "END";` [download]	[reply] [d/l] [select]