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class GFile

methods

GFile.flush

function GFile.flush()

This function takes no parameters and flushes all output to working file. The same as calling 'gzflush(file, Z_FINISH)' so writing to the file will most likely not work as expected. This is subject to change in the future if there is a strong reason for it to happen.

Reference:

GFile.read

function GFile.read(
  format1,
  ...
)

Reads the file file, according to the given formats, which specify what to read. For each format, the function returns a string with the characters read, or nil if it cannot read data with the specified format. When called without formats, it uses a default format that reads the entire next line (see below).

The available formats are

*a reads the whole file, starting at the current position. On end of file, it returns the empty string. *l reads the next line (skipping the end of line), returning nil on end of file. This is the default format. number reads a string with up to that number of characters, returning nil on end of file. If number is zero, it reads nothing and returns an empty string, or nil on end of file.

Unlink io.read, the *n format will not be available.

Reference:

GFile.lines

function GFile.lines()

Returns an iterator function that, each time it is called, returns a new line from the file. Therefore, the construction for line in file:lines() do ... end will iterate over all lines of the file. (Unlike gzip.lines, this function does not close the file when the loop ends.)

Reference:

GFile.seek

function GFile.seek(
  whence,
  offset
)

Sets and gets the file position, measured from the beginning of the file, to the position given by offset plus a base specified by the string whence, as follows:

set base is position 0 (beginning of the file); cur base is current position;

In case of success, function seek returns the final file position, measured in bytes from the beginning of ---the file. If this function fails, it returns nil, plus a string describing the error. The default value for whence is cur, and for offset is 0. Therefore, the call file:seek() returns the ---current file position, without changing it; the call file:seek("set") sets the position to the beginning of ---the file (and returns 0); and the call file:seek("end") sets the position to the end of the file, and ---returns its size.

This function is subject to limitations imposed by gzseek function from zlib library, such as the inability to use end as the base for seeking and the inability to seek backwards when writing.

Reference:

GFile.write

function GFile.write(
  value1,
  ...
)

Write the value of each of its arguments to the filehandle file.

The arguments must be strings or numbers. To write other values, use tostring or string.format before write

Example:

local g_file = gzip.open('test.gz', 'wb9')
assert(g_file)
for i = 1, 10 do
  g_file:write('This is line ' .. i, '\n')
end
g_file:close()

Reference:

GFile.close

function GFile.close()

Close the file.

Example:

local g_file = gzip.open('test.gz', 'wb9')
assert(g_file)
for i = 1, 10 do
  g_file:write('This is line ' .. i, '\n')
end
g_file:close()