example.lua

-- Just in case the user has luash installed as well
package.path = "./?.lua;" .. package.path

-- Remember that all arguments to print() are
-- automatically tostring'd.

local sh = require('sh')
local whoami, pwd, wc, ls, sed, echo, tr = sh("whoami", "pwd", "wc", "ls", "sed", "echo", "tr")

-- both the below print "ls is /bin/ls"
print((sh/"type ls")())
print(sh/"type ls") -- Works because print() invokes __tostring
print(sh%"type ls") -- % always returns a string.

local ref = sh/"type ls"
assert(type(ref) == "table")
print(ref) -- Invokes __tostring
ref() -- Invokes __call

local ret = sh._'pwd'
print(ret)

local stringReturn = sh%"type ls"
assert(stringReturn == "ls is /bin/ls")
local typec = sh.command("type")
local convoluted = tostring(typec("ls"))
assert(convoluted == stringReturn)



local echo = sh/"echo"
print(echo("division operator test"))

-- any shell command can be called as a function
print('User:', whoami())
print('Current directory:', pwd())

-- commands can be grouped into the pipeline as nested functions
print('Files in /bin:', wc(ls('/bin'), '-l'))
print('Files in /usr/bin:', wc(ls('/usr/bin'), '-l'))
print('files in both /usr/bin and /bin:', wc(ls('/usr/bin'), ls('/bin'), '-l'))

-- commands can be chained as in unix shell pipeline
print(ls('/bin'):wc("-l"))
-- Lua allows to omit parens
ls '/bin' : wc '-l' : print()

-- intermediate output in the pipeline can be stored into variables
local sedecho = sed(echo('hello', 'world'), 's/world/Lua/g')
print('output:', sedecho)
print('exit code:', sedecho.__exitcode)
local res = tr(sedecho, '[[:lower:]]', '[[:upper:]]')
print('output+tr:', res)

-- command functions can be created dynamically. Optionally, some arguments
-- can be prepended (like partially applied functions)
local e = sh.command('echo')
local greet = sh.command('echo hello')
print(e('this', 'is', 'some', 'output'))
print(greet('world'))
print(greet('foo'))

-- sh module itself can be called as a function
-- it's an alias for sh.command()
print((sh/"type ls")())