Misc.
PHP Manual

Changelog

The following changes have been made to classes/functions/methods of this extension.

VersionFunctionDescription
7.3.0definecase_insensitive has been deprecated and will be removed in version 8.0.0.
7.2.0packfloat and double types supports both Big Endian and Little Endian.
 unpackfloat and double types supports both Big Endian and Little Endian.
7.1.0unpackThe optional offset has been added.
7.0.15,7.1.1packThe "e", "E", "g" and "G" codes were added to enable byte order support for float and double.
7.0.0definearray values are allowed.
5.6.3packThe "q", "Q", "J" and "P" codes were added to enable working with 64-bit numbers.
5.5.0packThe "Z" code was added with equivalent functionality to "a" for Perl compatibility.
 unpackChanges were made to bring this function into line with Perl: The "a" code now retains trailing NULL bytes. The "A" code now strips all trailing ASCII whitespace (spaces, tabs, newlines, carriage returns, and NULL bytes). The "Z" code was added for NULL-padded strings, and removes trailing NULL bytes.
5.3.4sleepBefore PHP 5.3.4, on Windows, sleep always returns NULL when sleep has occurred, regardless of whether the sleep was interrupted or not.
5.3.0time_nanosleepThis function is now available on Windows platforms.
 time_sleep_untilThis function is now available on Windows platforms.
5.0.5php_check_syntaxThis function was removed from PHP.
5.0.3php_check_syntaxCalling exit after php_check_syntax resulted in a Segfault.
5.0.1php_check_syntaxerror_message is passed by reference.
4.2.1highlight_fileThis function is now also affected by safe_mode and open_basedir.

Misc.
PHP Manual