(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)

stream_set_blockingSet blocking/non-blocking mode on a stream


stream_set_blocking(resource $stream, bool $enable): bool

Sets blocking or non-blocking mode on a stream.

This function works for any stream that supports non-blocking mode (currently, regular files and socket streams).



The stream.


If enable is false, the given stream will be switched to non-blocking mode, and if true, it will be switched to blocking mode. This affects calls like fgets() and fread() that read from the stream. In non-blocking mode an fgets() call will always return right away while in blocking mode it will wait for data to become available on the stream.


Gibt bei Erfolg true zurück. Bei einem Fehler wird false zurückgegeben.



On Windows, this has no affect on local files. Non-blocking IO for local files is not supported on Windows.

Siehe auch

  • stream_select() - Runs the equivalent of the select() system call on the given arrays of streams with a timeout specified by seconds and microseconds
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User Contributed Notes 3 notes

11 years ago
On Windows this function does not work with pipes opened with proc_open (,,
MagicalTux at ookoo dot org
17 years ago
When you use fwrite() on a non-blocking stream, data isn't discarded silently as t dot starling said.

Remember that fwrite() returns an int, and this int represents the amount of data really written to the stream. So, if you see that fwrite() returns less than the amount of written data, it means you'll have to call fwrite() again in the future to write the remaining amount of data.

You can use stream_select() to wait for the stream to be available for writing, then continue writing data to the stream.

Non-blocking streams are useful as you can have more than one non-blocking stream, and wait for them to be available for writing.
ayon at hyurl dot com
7 years ago
It is necessary to be noted that stream_set_blocking() and stream_set_timeout() does not work width standard I/O streams, such as STDIN and STDOUT.
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