An erlang implementation of the UN*X dc(1) (desk calculator).

Run from a pipe:
$ echo '2 2+f' | ./dc

Run interactively:
$ ./dc

From an erlang shell (the first 10 numbers in the fibonacci sequence):
1> {St,D} = dc:eval("[sbsa lalb lalb+]sf 0 1[lfx z10>l]slllx"), ok.
ok
2> St.
[34,21,13,8,5,3,2,1,1,0]
3> dict:to_list(D).
[{"b","\r"},
 {"l",["lfx z10>l"]},
 {"f",["sbsa lalb lalb+"]},
 {"a",[21]}]
4>

Operators implemented:
+, -, *, /, %, _, ^, v, c, d, r, q, Q, p, f, z, x
<r, =r, >r, sr, lr, Sr, Lr

Push a string to the stack:
[hello world!]

Push three numbers to the stack:
1 2 3

RTFM:
$ man 1 dc