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@@ -1,4 +1,8 @@ |
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local mtar = {} |
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local versions = {} |
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versions[0] = {nlf = ">I2", flf = ">I2"} -- original version format |
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versions[1] = {nlf = ">I2", flf = ">I8"} -- extended file size format |
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mtar.versions = versions |
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local function cleanPath(path) |
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local pt = {} |
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@@ -12,8 +16,9 @@ local function cleanPath(path) |
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return table.concat(pt,"/") |
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end |
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function mtar.genHeader(fname,len) -- string number -- string -- generate a header for file *fname* when provided with file length *len* |
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return string.format("%s%s%s", string.pack(">I2",fname:len()), fname, string.pack(">I2",len)) |
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function mtar.genHeader(fname,len,version) -- string number -- string -- generate a header for file *fname* when provided with file length *len* |
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version=version or 1 |
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return string.format("\255\255%s%s%s%s", string.char(version), string.pack(versions[version].nlf,fname:len()), fname, string.pack(versions[version].flf,len)) |
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end |
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function mtar.iter(stream) -- table -- function -- Given buffer *stream*, returns an iterator suitable for use with *for* that returns, for each iteration, the file name, a function to read from the file, and the length of the file. |
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@@ -27,14 +32,17 @@ function mtar.iter(stream) -- table -- function -- Given buffer *stream*, return |
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while remain > 0 do |
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remain=remain-#stream:read(math.min(remain,2048)) |
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end |
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local version = 0 |
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local nlen = string.unpack(">I2", stream:read(2) or "\0\0") |
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if nlen == 0 then |
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return |
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elseif nlen == 65535 then -- versioned header |
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version = string.byte(stream:read(1)) |
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nlen = string.unpack(versions[version].nlf, stream:read(string.packsize(versions[version].nlf))) |
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end |
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local name = cleanPath(stream:read(nlen)) |
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local fsize = string.unpack(">I2", stream:read(2)) |
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remain = fsize |
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return name, read, fsize |
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remain = string.unpack(versions[version].flf, stream:read(string.packsize(versions[version].flf))) |
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return name, read, remain |
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end |
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end |
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