.TH PFC 1 pfc\-VERSION
.SH NAME
pfc \- postfix calculator
.SH SYNOPSIS
.B pfc
.SH DESCRIPTION
pfc is an interactive postfix, or reverse Polish notation, calculator.
.
.SH USAGE
.
.SS Keyboard commands
.
.TP
.B Shift-q
Quit.
.
.TP
.B [0..9]
Enter a digit into the input buffer.
pfc works with floating point numbers so the
.B .
character is OK as well.
.
.TP
.B Backspace
Remove a digit from the input buffer.
.
.TP
.B Enter
Push the number in the input buffer to the stack.
.
.TP
.B Shift-j
Swap the bottom (most recently pushed) item on the stack with the input buffer.
If the input buffer is empty this simply moves the most recently pushed item
back into the input buffer.
.
.TP
.B Shift-k
The same as
.BR Shift-j .
.
.TP
.B Shift-d
Delete the contents of the input buffer.
.
.TP
.B Shift-c
Delete the contents of the input buffer and the stack.
.
.TP
.B Shift-a
Toggle between degree and radian mode.
.
.TP
.B Shift-n
Negation. If there is a number in the buffer, negate it. Otherwise, negate the
bottom number in the stack.
.
.SS Operators
.
.TP
.B +
Addition.
.
.TP
.B -
Subtraction.
.
.TP
.B *
Multiplication.
.
.TP
.B /
Division.
.
.TP
.B %
Modulo/remainder.
.
.TP
.B ^
Exponentiation.
.
.SS Functions
.
.TP
.B sin
Sine function.
.
.TP
.B cos
Cosine function.
.
.TP
.B tan
Tangent function.
.
.TP
.B asin
Inverse sine function.
.
.TP
.B acos
Inverse cosine function.
.
.TP
.B atan
Inverse tangent function.
.
.TP
.B deg
Convert radians to degrees.
.
.TP
.B rad
Convert degrees to radians.
.
.SS Constants
.
.TP
.B pi
Archimedes’ constant (π).
.
.TP
.B e
Euler’s number (e).