gzip File Access Functions

1. Overview

This library supports reading and writing files in gzip (.gz) format with an interface similar to that of stdio, using the functions that start with "gz". The gzip format is different from the zlib format. gzip is a gzip wrapper, documented in RFC 1952, wrapped around a deflate stream

2. Module

2.1. Example Usage

require "gzfile"

local gzf = gzfile.open("foo.gz")
for line in gzf:lines() do
    -- process line
end
gzf:close()

2.2. Functions

2.2.1. open

local gzf, err = gzfile.open(filename, mode, buffer_size)

Opens a file in the specified mode

Arguments

• filename (string) File to open.
• mode (string) defaults to "rb"
• buffer_size (unsigned) Internal buffer size (default 8192)

Return

• gzf (userdata object/nil)
• err (nil/string)

2.2.2. version

require "gzfile"
local v = gzfile.version()
-- v == "0.0.1"

Returns a string with the running version of the gzfile module.

Arguments

• none

Return

• Semantic version string

2.3. Methods

2.3.1. lines

local iter = gzf:lines(max_bytes)

Creates an iterator to read the file one line at a time.

Arguments

• max_bytes (unsigned) The maximum number of bytes allowed in a line after which the line is truncated (default 1MB).

Return

• line (string/nil) Returs nil at EOF

2.3.2. close

gzf:close()

Closes the open file

Arguments

• none

Return

• none