Description:
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Hello, I would like to use "php -a" (php cli interactive mode) and input via a fifo.

it seems that while using it with a Character Device / Terminal.
it will behave accordingly.

but while piping its stdin .. it won't interact - it will block its stdout.

due to the fact it is an interactive mode, I can only assume its a misbehavior, I wouldn't expect interactive mode to block.


Reproduce code:
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1. mkfifo fifo
2. cat fifo | strace php -a

3. cat > fifo
<?php echo "Hello World"; ?>

4. strace will reveal it been read, but nothing will be written back unless about 8K buffer stack is full, or EOF.



Expected result:
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I expect "interactive mode" not to block while piping its STDIN. (without a Character Device / Terminal)


Actual result:
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It would block unless EOF reached OR about 8K buffer is filled up.

and only then, it will write back to stdout.