A erlang script to change pairs

pair

#!/usr/bin/env escript

my_name()  -> "Andrzej Sliwa".
my_email() -> "andrzej.sliwa@my_domain.com".

pairs() ->
  [{"an-ar",
    [{left, my_name()}, {right, "Artur Kowalski"},
     {email, "andrzej+artur@my_domain.com"}]},
  {"an-jan",
    [{left, my_name()}, {right, "Jan Kowalski"},
     {email, "andrzej+jan@my_domain.com"}]}].

main(["help"]) -> usage();
main(["-h"])   -> usage();
main(["/h"])   -> usage();
main([]) ->
    switch_git_config(my_name(), my_email());
main([PairName]) ->
    Pair  = proplists:get_value(PairName, pairs()),
    Left  = proplists:get_value(left, Pair),
    Right = proplists:get_value(right, Pair),
    Email = proplists:get_value(email, Pair),
    Name = io_lib:format("~s + ~s", [Left, Right]),
    switch_git_config(Name, Email),
    io:format("Pairing ~s~n", [Name]).

usage() ->
    io:format("./pair [name]: pair two people~n"),
    io:format("./pair       : switch to just me~n").

switch_git_config(Name, Email) ->
    cmd("git config user.name '~s'", [Name]),
    cmd("git config user.email ~s", [Email]).

cmd(Command, Args) ->
    io:format("~s", [os:cmd(io_lib:format(Command, Args))]).