Danilo at 03:00, 23 January 2022

2022-01-23T03:00:17Z

← Older revision		Revision as of 03:00, 23 January 2022
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			<pageclass class="#3cc882" subcaption="File function"></pageclass>
	__NOTOC__		__NOTOC__
	This function attempts to read an unsigned byte (native type) from a file and returns it. The amount of bytes read should be one.		This function attempts to read an unsigned byte (native type) from a file and returns it. The amount of bytes read should be one.

Quiret at 22:49, 19 January 2022

2022-01-19T22:49:15Z

← Older revision		Revision as of 22:49, 19 January 2022
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	-- Write the network identifier.		-- Write the network identifier.
	theFile.writeUByte( info.networkId );		theFile:writeUByte( info.networkId );

	-- Check what we are dealing with.		-- Check what we are dealing with.
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	local numIteration = #data;		local numIteration = #data;
	do		do
	theFile.writeUInt( numIteration );		theFile:writeUInt( numIteration );

	local n = 1;		local n = 1;

Danilo: Created page with "NOTOC This function attempts to read an unsigned byte (native type) from a file and returns it. The amount of bytes read should be one. ==Syntax== unsigned_byte file:readUByte () ==Returns== Returns the unsigned byte if it was successfully read from the file, '''false''' otherwise. ==Example==
This snippet writes a Lua type into a file stream. The lua type can be any..."

2022-01-19T03:30:25Z

Created page with "__NOTOC__ This function attempts to read an unsigned byte (native type) from a file and returns it. The amount of bytes read should be one. ==Syntax== <syntaxhighlight lang="lua"> unsigned_byte file:readUByte () </syntaxhighlight> ==Returns== Returns the unsigned byte if it was successfully read from the file, '''false''' otherwise. ==Example== <section name="Client" class="client" show="true"> This snippet writes a Lua type into a file stream. The lua type can be any..."

New page

__NOTOC__
This function attempts to read an unsigned byte (native type) from a file and returns it. The amount of bytes read should be one.

==Syntax==
<syntaxhighlight lang="lua">
unsigned_byte file:readUByte ()
</syntaxhighlight>

==Returns==
Returns the unsigned byte if it was successfully read from the file, '''false''' otherwise.

==Example==
<section name="Client" class="client" show="true">
This snippet writes a Lua type into a file stream. The lua type can be anything that can be traversed over the network. It must be context-less data.
<syntaxhighlight lang="lua">
-- A table specifying descriptor information about Lua types.
local typeDescriptors = {
["boolean"] = { networkId = 0 },
["number"] = { networkId = 1 },
["string"] = { networkId = 2 },
["table"] = { networkId = 3 },
["nil"] = { networkId = 4 }
};

local function isValidNetworkType( typeName )
return not ( typeDescriptors[typeName] == nil );
end

local function writeLuaData( theFile, data )
-- Get the descriptor for the type.
local typeName = rawtype(data);
local info = typeDescriptors[typeName];

-- Some types cannot be transfered over the network.
if not ( info ) then return; end;

-- Write the network identifier.
theFile.writeUByte( info.networkId );

-- Check what we are dealing with.
if ( typeName == "boolean") then
theFile:writeBoolean( data );
elseif ( typeName == "number" ) then
theFile:writeDouble( data );
elseif ( typeName == "string" ) then
theFile:writeUShort( #data );
theFile:write( data );
elseif ( typeName == "table" ) then
-- First write iterated entries of the table.
local numIteration = #data;
do
theFile.writeUInt( numIteration );

local n = 1;

while ( n <= numIteration ) do
writeLuaData( data[n] );
n = n + 1;
end
end

-- Next write the data entries.
do
-- Construct a data entry table.
local dataTable = {};
local entryCount = 0;

for m,n in pairs( data ) do
if ( isValidNetworkType( rawtype( n ) ) ) then
if not ( rawtype( n ) == "number" ) or ( n <= 0 ) or ( n > numIteration ) then
entryCount = entryCount + 1;

dataTable[entryCount] = {
key = m,
value = n
};
end
end
end

-- Write the amount of data entries.
theFile:writeUInt( entryCount );

-- Write all data entries.
for m,n in ipairs( dataTable ) do
writeLuaData( n.key );
writeLuaData( n.value );
end
end
elseif ( typeName == "nil" ) then
-- Do nothing.
end
end

-- task for the reader: write a function to read the Lua data again.
</syntaxhighlight>
</section>
{{:Modules/FileSystem/file/functions}}

Modules/FileSystem/file/readUByte - Revision history

Danilo at 03:00, 23 January 2022

Quiret at 22:49, 19 January 2022