--[[

General Lua Libraries for Lua 5.1, 5.2 & 5.3

Copyright (C) 2002-2018 stdlib authors

]]

--[[--

Additions to the core io module.

The module table returned by `std.io` also contains all of the entries from

the core `io` module table. An hygienic way to import this module, then,

is simply to override core `io` locally:

local io = require 'std.io'

@corelibrary std.io

]]

local _ = require 'std._base'

local argscheck = _.typecheck and _.typecheck.argscheck

local catfile = _.io.catfile

local leaves = _.tree.leaves

local split = _.string.split

_ = nil

local _ENV = require 'std.normalize' {

'io',

_G = _G, -- FIXME: don't use the host _G as an API!

concat = 'table.concat',

dirsep = 'package.dirsep',

format = 'string.format',

gsub = 'string.gsub',

input = 'io.input',

insert = 'table.insert',

io_type = 'io.type',

merge = 'table.merge',

open = 'io.open',

output = 'io.output',

popen = 'io.popen',

stderr = 'io.stderr',

stdin = 'io.stdin',

write = 'io.write',

}

--[[ =============== ]]--

--[[ Implementation. ]]--

--[[ =============== ]]--

local M

local function input_handle(h)

if h == nil then

return input()

elseif type(h) == 'string' then

return open(h)

end

return h

end

local function slurp(file)

local h, err = input_handle(file)

if h == nil then

argerror('std.io.slurp', 1, err, 2)

end

if h then

local s = h:read('*a')

h:close()

return s

end

end

local function readlines(file)

local h, err = input_handle(file)

if h == nil then

argerror('std.io.readlines', 1, err, 2)

end

local l = {}

for line in h:lines() do

l[#l + 1] = line

end

h:close()

return l

end

local function writelines(h, ...)

if io_type(h) ~= 'file' then

write(h, '\n')

h = output()

end

for v in leaves(ipairs, {...}) do

h:write(v, '\n')

end

end

local function process_files(fn)

-- N.B. 'arg' below refers to the global array of command-line args

if len(arg) == 0 then

insert(arg, '-')

end

for i, v in ipairs(arg) do

if v == '-' then

input(stdin)

else

input(v)

end

fn(v, i)

end

end

local function warnfmt(msg, ...)

local prefix = ''

local prog = rawget(_G, 'prog') or {}

local opts = rawget(_G, 'opts') or {}

if prog.name then

prefix = prog.name .. ':'

if prog.line then

prefix = prefix .. str(prog.line) .. ':'

end

elseif prog.file then

prefix = prog.file .. ':'

if prog.line then

prefix = prefix .. str(prog.line) .. ':'

end

elseif opts.program then

prefix = opts.program .. ':'

if opts.line then

prefix = prefix .. str(opts.line) .. ':'

end

end

if #prefix > 0 then

prefix = prefix .. ' '

end

return prefix .. format(msg, ...)

end

local function warn(msg, ...)

writelines(stderr, warnfmt(msg, ...))

end

--[[ ================= ]]--

--[[ Public Interface. ]]--

--[[ ================= ]]--

local function X(decl, fn)

return argscheck and argscheck('std.io.' .. decl, fn) or fn

end

M = {

--- Diagnostic functions

-- @section diagnosticfuncs

--- Die with error.

-- This function uses the same rules to build a message prefix

-- as @{warn}.

-- @function die

-- @string msg format string

-- @param ... additional arguments to plug format string specifiers

-- @see warn

-- @usage

-- die('oh noes!(%s)', tostring(obj))

die = X('die(string, [any...])', function(...)

error(warnfmt(...), 0)

end),

--- Give warning with the name of program and file(if any).

-- If there is a global `prog` table, prefix the message with

-- `prog.name` or `prog.file`, and `prog.line` if any. Otherwise

-- if there is a global `opts` table, prefix the message with

-- `opts.program` and `opts.line` if any.

-- @function warn

-- @string msg format string

-- @param ... additional arguments to plug format string specifiers

-- @see die

-- @usage

-- local OptionParser = require 'std.optparse'

-- local parser = OptionParser 'eg 0\nUsage: eg\n'

-- _G.arg, _G.opts = parser:parse(_G.arg)

-- if not _G.opts.keep_going then

-- require 'std.io'.warn 'oh noes!'

-- end

warn = X('warn(string, [any...])', warn),

--- Path Functions

-- @section pathfuncs

--- Concatenate directory names into a path.

-- @function catdir

-- @string ... path components

-- @return path without trailing separator

-- @see catfile

-- @usage

-- dirpath = catdir('', 'absolute', 'directory')

catdir = X('catdir(string...)', function(...)

return(gsub(concat({...}, dirsep), '^$', dirsep))

end),

--- Concatenate one or more directories and a filename into a path.

-- @function catfile

-- @string ... path components

-- @treturn string path

-- @see catdir

-- @see splitdir

-- @usage

-- filepath = catfile('relative', 'path', 'filename')

catfile = X('catfile(string...)', catfile),

--- Remove the last dirsep delimited element from a path.

-- @function dirname

-- @string path file path

-- @treturn string a new path with the last dirsep and following

-- truncated

-- @usage

-- dir = dirname '/base/subdir/filename'

dirname = X('dirname(string)', function(path)

return(gsub(path, catfile('', '[^', ']*$'), ''))

end),

--- Split a directory path into components.

-- Empty components are retained: the root directory becomes `{'', ''}`.

-- @function splitdir

-- @param path path

-- @return list of path components

-- @see catdir

-- @usage

-- dir_components = splitdir(filepath)

splitdir = X('splitdir(string)', function(path)

return split(path, dirsep)

end),

--- IO Functions

-- @section iofuncs

--- Process files specified on the command-line.

-- Each filename is made the default input source with `io.input`, and

-- then the filename and argument number are passed to the callback

-- function. In list of filenames, `-` means `io.stdin`. If no

-- filenames were given, behave as if a single `-` was passed.

-- @todo Make the file list an argument to the function.

-- @function process_files

-- @tparam fileprocessor fn function called for each file argument

-- @usage

-- #! /usr/bin/env lua

-- -- minimal cat command

-- local io = require 'std.io'

-- io.process_files(function() io.write(io.slurp()) end)

process_files = X('process_files(function)', process_files),

--- Read a file or file handle into a list of lines.

-- The lines in the returned list are not `\n` terminated.

-- @function readlines

-- @tparam[opt=io.input()] file|string file file handle or name;

-- if file is a file handle, that file is closed after reading

-- @treturn list lines

-- @usage

-- list = readlines '/etc/passwd'

readlines = X('readlines(?file|string)', readlines),

--- Perform a shell command and return its output.

-- @function shell

-- @string c command

-- @treturn string output, or nil if error

-- @see os.execute

-- @usage

-- users = shell [[cat /etc/passwd | awk -F: '{print $1;}']]

shell = X('shell(string)', function(c) return slurp(popen(c)) end),

--- Slurp a file handle.

-- @function slurp

-- @tparam[opt=io.input()] file|string file file handle or name;

-- if file is a file handle, that file is closed after reading

-- @return contents of file or handle, or nil if error

-- @see process_files

-- @usage

-- contents = slurp(filename)

slurp = X('slurp(?file|string)', slurp),

--- Write values adding a newline after each.

-- @function writelines

-- @tparam[opt=io.output()] file h open writable file handle;

-- the file is **not** closed after writing

-- @tparam string|number ... values to write(as for write)

-- @usage

-- writelines(io.stdout, 'first line', 'next line')

writelines = X('writelines(?file|string|number, [string|number...])', writelines),

}

return merge(io, M)

--- Types

-- @section Types

--- Signature of @{process_files} callback function.

-- @function fileprocessor

-- @string filename filename

-- @int i argument number of *filename*

-- @usage

-- local fileprocessor = function(filename, i)

-- io.write(tostring(i) .. ':\n===\n' .. io.slurp(filename) .. '\n')

-- end

-- io.process_files(fileprocessor)