Penlight

• Index

Examples

• seesubst.lua
• sipscan.lua
• symbols.lua
• test-cmp.lua
• test-data.lua
• test-listcallbacks.lua
• test-pretty.lua
• test-symbols.lua
• testapp.lua
• testclone.lua
• testconfig.lua
• testglobal.lua
• testinputfields.lua
• testinputfields2.lua
• testxml.lua
• which.lua

Libraries

• pl
• pl.Set
• pl.app
• pl.array2d
• pl.class
• pl.compat
• pl.comprehension
• pl.config
• pl.data
• pl.dir
• pl.file
• pl.func
• pl.import_into
• pl.input
• pl.lapp
• pl.lexer
• pl.luabalanced
• pl.operator
• pl.path
• pl.permute
• pl.pretty
• pl.seq
• pl.sip
• pl.strict
• pl.stringio
• pl.stringx
• pl.tablex
• pl.template
• pl.test
• pl.text
• pl.types
• pl.url
• pl.utils
• pl.xml

Classes

• pl.Date
• pl.List
• pl.Map
• pl.MultiMap
• pl.OrderedMap

Manual

• Introduction
• Tables and Arrays
• Strings. Higher-level operations on strings.
• Paths and Directories
• Date and Time
• Data
• Functional Programming
• Additional Libraries
• Technical Choices

which.lua

-- a simple implementation of the which command. This looks for
-- the given file on the path. On windows, it will assume an extension
-- of .exe if no extension is given.
local List = require 'pl.List'
local path = require 'pl.path'
local app = require 'pl.app'

local pathl = List.split(os.getenv 'PATH',path.dirsep)

function which (file)
    local res = pathl:map(path.join,file)
    res = res:filter(path.exists)
    if res then return res[1] end
end

local _,lua = app.lua()
local file = arg[1] or lua -- i.e. location of lua executable
local try

if not file then return print 'must provide a filename' end

if path.extension(file) == '' and path.is_windows then
    try = which(file..'.exe')
else
    try = which(file)
end

if try then print(try) else print 'cannot find on path' end