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Generating GUIDs

From MDC

GUIDs are used in Mozilla programming for identifying several types of entities, including XPCOM Interfaces (this type of GUIDs is callled IID), components (CID), and add-ons, like extensions and themes, although add-ons can (and should) be identified with IDs of form extensionname@organization.tld since Firefox 1.5.

Contents

[edit] Canonical form

The common form of a GUID is xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx, where each x stands for a hexadecimal digit. There are a number of tools that can be used to generate a GUID in the canonical form.

[edit] Online tools

[edit] Windows

Windows users can use the GuidGen tool from Microsoft to obtain a GUID. (This tool is also part of MS Visual C++)

[edit] Linux

Use /usr/bin/uuidgen. This can be found in package libuuid1 (Debian).

[edit] Perl

jkeiser's Mozilla tools include a UUID generator with output format of both C++ and IDL style.

[edit] nsIUUIDGenerator

A UUID can be generated from privileged Mozilla code using nsIUUIDGenerator. See the linked page for details.

[edit] COM/XPCOM format

When #define-ing IIDs and CIDs in Mozilla C++ code, you generally use the following format: 

// xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx
#define NS_...ID \
{ 0xXXXXXXXX, 0xXXXX, 0xXXXX, \
  { 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX, 0xXX } }

You can generate code in this format using one of the following tools.

[edit] Online tools

[edit] guidgen

guidgen.exe, part of Microsoft Visual Studio, can generate UUIDs in this format.

[edit] bash

You can put the following into your .bashrc file: 

uuidgen-c++()
{
       local UUID=$(uuidgen)
       echo "// $UUID"
       echo "#define NS__IID \\"
       echo "{ 0x${UUID:0:8}, 0x${UUID:9:4}, 0x${UUID:14:4}, \\"
       echo -n "  { 0x${UUID:19:2}, 0x${UUID:21:2}, 0x${UUID:24:2}, "
       echo -n "0x${UUID:26:2}, 0x${UUID:28:2}, 0x${UUID:30:2}, "
       echo "0x${UUID:32:2}, 0x${UUID:34:2} } }"
}

[edit] Perl 

#!/usr/bin/perl
$uuid = `uuidgen`;
chomp $uuid;
print $uuid, "\n";
@parts = ($uuid =~ /^(.{8})-(.{4})-(.{4})-(..)(..)-(..)(..)(..)(..)(..)(..)$/);
print "{ 0x$parts[0], 0x$parts[1], 0x$parts[2], \\", "\n", " { ";
for (3 .. 9) {
    print "0x$parts[$_], ";
}
print "0x$parts[10] } }", "\n";
Retrieved from "http://developer.mozilla.org/en/docs/Generating_GUIDs"