note 104836 added to function.hash-file

From: Date: Sun, 10 Jul 2011 11:56:14 +0000
Subject: note 104836 added to function.hash-file
Groups: php.notes 
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I have verified that the output of the "crc32" is the ITU I.363.5 algorithm (a.k.a. AAL5 CRC - popularised by BZIP2 but also used in ATM transmissions - the algorithm is the same as that in POSIX 1003.2-1992 in Cksum but that stuffs the size into the CRC at the end for extra measure). However, the output is expressed in reverse order to many CRC programs. Using the "standard" crctest.txt (numbers 1 to 9 in sequence - google it, it's not hard to find), php will output 181989fc - many other (Intel little endian) programs would output this as fc891918, hence the confusion (that I have had, at least). The crc32b is the 32-bit Frame Check Sequence of ITU V.42 (used in Ethernet and popularised by PKZip). The output from this CRC is popularised in Intel little endian format and would produce cbf43926 on the same file. ---- Server IP: 69.147.83.197 Probable Submitter: 81.31.102.232 ---- Manual Page -- http://www.php.net/manual/en/function.hash-file.php Edit -- https://master.php.net/note/edit/104836 Del: integrated -- https://master.php.net/note/delete/104836/integrated Del: useless -- https://master.php.net/note/delete/104836/useless Del: bad code -- https://master.php.net/note/delete/104836/bad+code Del: spam -- https://master.php.net/note/delete/104836/spam Del: non-english -- https://master.php.net/note/delete/104836/non-english Del: in docs -- https://master.php.net/note/delete/104836/in+docs Del: other reasons-- https://master.php.net/note/delete/104836 Reject -- https://master.php.net/note/reject/104836 Search -- https://master.php.net/manage/user-notes.php

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