Editing mirc/identifiers/$sha512

{{mirc title|$sha512 identifier}}'''$sha512''' calculates the [[sha512 hash]] of a text, {{mirc|binary variables|binary variable}}, or file. Hash is 160-bits, shown as 40 lower-case hexadecimal characters.

== Synopsis ==
<pre>$sha512(plaintext|&binaryvar|filename,[N])</pre>

== Parameters ==
'''plaintext''' - Used with N = 0, just the string you want the sha512 hash of

'''&binaryvar''' - A binary variable, used with N = 1, return the sha512 hash of the content of the binvar

'''filename''' - A filename, used with N = 2, return the sha512 hash of the content of the file

'''N:''' Optional integer 0-2, where 0 indicates data is treated as plaintext, 1 indicates a &binary variable, 2 treats data as contents of a filename<br />

If the N parameter isn't used, the default 0 is used (which is different than $crc which has default of N=2.)

== Properties ==
None

== Example ==
Echo the SHA1 hash of plain text string ''abc'' to the active window:
<pre>//echo -a $sha1(abc)
or
//echo -a $sha1(abc,0)</pre>
The DATA is case-sensitive, so hash of "abc" is different than hash of "ABC"

Echo the SHA1 hash of the zero-length null string to the active window:
<pre>//echo -a $sha1($null)</pre>

Echo the SHA1 hash of the first 1000 bytes of the mIRC program you're running to the active window:
<pre>//bread $qt($mircexe) 0 1000 &snip | echo -a $sha1(&snip,1)</pre>

Echo the SHA1 hash of the contents of the mIRC program you're running to the active window:
<pre>//echo -a $sha1($mircexe,2)</pre>

Suggested Uses:
* Quick way to compare if 2 files are identical. (First check should always be comparing file sizes.)
* Quick way to check if a file's contents have changed since stored sha1 hash was made.
* Verify downloaded file hasn't been corrupted, matches the sender's original.
<br />
Note that because the default is N=0, '''$sha1($mircexe)''' is the SHA1 hash for the plaintext text string of the drive:\path\filename for the mIRC you're running, and not the hash of the filename contents. This differs from $crc($mircexe) giving the checksum of the filename contents because $crc has default of N=2.<br />
mIRC v7.x Unicode-encodes plaintext before providing to $sha1, so v7.x and v6.x return different answers for //echo -a $sha1($chr(233))<br />

If the text doesn't have Unicode code points above 255, to avoid having Unicode points 128-255 encoded to 2-byte pairs, the text must be fed to $sha1 as a binary variable:<br />

<pre>//bset -ta &string 1 chloé | echo -a $sha1(&string,1)</pre>

== Error Messages ==
Note that $sha1 differs from $crc in that it generates error for non-existent files instead of returning hash of $null string. Also, hex string returned by $sha1 is lowercase while $crc returns uppercase hex.

<pre>* Error accessing file: $sha1</pre>
Either file does not exist, or file permissions don't allow the file to be read. i.e. $sha1(non-existent-file,2) or $sha1(c:\hiberfil.sys,2)

<pre>* Invalid parameters: $sha1</pre>
Either using a zero-length/non-existent binary variable or specifying an N where $int(%N) isn't 0-2.

<pre>Both above errors halt execution of the script</pre>

== Compatibility ==
{{mIRC compatibility|6.3}}

== See also ==
* {{mIRC|$crc}}
* {{mIRC|$md5}}
* {{mIRC|$sha256}}
* {{mIRC|$sha384}}
* {{mIRC|$sha512}}
* [[List of identifiers - mIRC]]
{{mIRC identifier list}}
[[Category:mIRC identifiers|mircini]]