MTA:Eir/FileSystem/file/readShort

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Revision as of 08:50, 30 January 2014 by The GTA (talk | contribs) (Created page with "__NOTOC__ This function attempts to read a short (native type) from a file and returns it. The amount of bytes read should be two. ==Syntax== <syntaxhighlight lang="lua"> short file.readShort ...")
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This function attempts to read a short (native type) from a file and returns it. The amount of bytes read should be two.

Syntax

short file.readShort ()

Returns

Returns the short integer if it was successfully read from the file, false otherwise.

Example

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Client

This snippet reads and writes string buffers into a custom file format.

local function writeBuffers( outFile, buffers )
    -- Write header information.
    outFile.writeInt( #buffers ); -- number of buffers
    
    -- Write the buffers.
    for m,n in ipairs( buffers ) do
        local bufferContent = tostring( n );

        -- Write header of buffer.
        outFile.writeShort( #bufferContent ); -- length of buffer

        -- Write the content
        outFile.write( bufferContent );
    end
end

local function readBuffers( inFile )
    local buffers = {};

    -- Read header information.
    local numBuffers = inFile.readInt();

    -- Make sure we read the int correctly.
    -- Fails if the file has less than 4 bytes to read.
    if ( numBuffers ) then
        local n = 1;

        while ( n <= numBuffers ) do
            -- Read buffer header.
            local bufferSize = inFile.readShort();

            -- We always have to add the amount of buffers specified by the header.
            -- Hence we always add a buffer to the result array.
            local buffer = "";

            if ( bufferSize ) then
                -- Read the buffer.
                buffer = inFile.read( bufferSize );
            end

            -- Append the result buffer.
            buffers[n] = buffer;

            n = n + 1;
        end
    end

    return buffers;
end

-- Manager some buffers in a file.
local myBuffers = { "Hello World!", "Cooking eggs on a frying pan", "The American Pizzas taste awesome", "There is no bathroom." };

local theFile = fileCreate( "buffers.dat" );

-- First write the buffers into the file.
writeBuffers( theFile, myBuffers );

-- Now retrieve them again.
theFile.seek( 0, "set" );

myBuffers = readBuffers( theFile );

-- Output the buffers.
for m,n in ipairs( myBuffers ) do
    outputChatBox( n );
end

FileSystem File Functions