.Dd Created:2025-10-15|Updated:2025-10-15|
.de ocsi
\\$*
,
..
.de oxr
.ocsi .Xr \\$*
..
.de oit
.It
\\$*
..
.de obdi
.Bl -dash -compact
.oit \\$*
..
.de obdl
.Bd -literal -compact
\\$*
..
.de onote
.Bl -hang -compact
.oit \\$*
.El
..
.de ocomm
.Bl -diag -compact
.oit \\$*
.El
..
.de opsy
.Pp
.Sy - \\$*
..
.de obc
.Bl -column \\$*
..
.de obc2
.obc opt desc
..
.de obc3
.obc option arguments description
..
.Dt DC oh
.Os OpenBSD , linux |
.Nm dc 
.Nd desk calculator - rpn
.Sh DESCRIPTION
It's a stack calculator using Reverse Polish Notation.
Values are pushed into a stack and operations pop values from the stack in reverse order.
.Ss
.Ss Example
To get the result of 1 + 2:
.obdl 1 2 + f
3
.Ed
.Bl -enum -compact
.oit 1 is pushed into the stack.
.oit 2 is pushed into the stack.
.oit + pops the top two values from the stack, adds them and the result is pushed into the stack.
.oit f prints the complete stack.
.El
.Ss Another example
To get the result of 2 * 3 + 4:
.obdi one way to do it:
.obdl 2 3 * 4 + f
10
.Ed
.D1 + pops 4 and *, therefore * pops 2 and 3, multiplies them and 6 is sent into the stack resulting in 6 4 +.
.oit another way to do it:
.obdl 4 2 3 * + f
10
.Ed
.D1 + pops * which pops 2 and 3 to get 6 which is pushed into the stack resulting in 4 6 +.
.El
.Ss Scripting
dc can be called with file:
.Li dc filename
.Sh OPERATIONS
The common operation are supported: + - * / ^.
.obc2
.It % Ta | pops the top two values, divides the second popped value by the first one and pushes the remainder into the stack. Eg.: 8 4 % fc 0, 8 5 % fc 3.
.It ~ Ta | similar but returns the quotient and remainder: 8 4 ~ fc 0 2, 8 5 ~ fc 3 1
.It v Ta | pops the top value off the stack and calculates the square root.
.El
.Sh PRINTING
.obc2
.It f Ta | prints stack.
.It p Ta | prints value on top of the stack with newline.
.It n Ta | prints value on top of the stack without newline.
.El
.Sh STACK
.obc2
.It c Ta | clears the stack.
.It r Ta | swap the top two values of the stack.
.It d Ta | duplicates value on top of the stack.
.El
.Sh REGISTERS
.obc2
.It sr Ta | pops the top value off the stack and stores it into the register r. (r can be any single character)
.It Sr Ta | same as s but overwrites the original value of the register.
.It lr Ta | loads a copy of the value of register r.
.It Lr Ta | loads the value of register r removing it from the register.
.El
.Sh PARAMETERS
.obc2
.It k Ta | pop the top value off the stack and use it as the precision parameter.
.El
.Sh STRINGS
Strings can be stored as [string], this can be used to store strings or operations as macros which can be saved as a macro.
.Ss Example
.obdl [the string]p
the string
[2 2 +]Sa
laxp
4
.Ed
.Ss Macros
Macros can be invoked based on conditions:
.obc2
.It >r Ta | compare the top two values of the stack and runs r if the top value of the stack is greater.
.It !>r Ta | similar but runs r if the top value is not greater. (less or equal)
.It <r Ta | runs r if the top value is lower than the seconf value..
.It !<r Ta | runs r if the top value is not lower than the second value. (greater or equal)
.It =r Ta | runs r if the top two values of the stack are equal.
.It !=r Ta | runs r if the top two values of the stack are not equal.
.El
.Sy Examples:
.Pp
Considering the top two values 1 2, r could run with the following comparisons:
>r, !<r, !=r.
r will not run with the following comparisons:
!>r, <r, =r.
.obdl
[runs]Sa
[lap]Sb
1 2 >b
runs
1 2 !>b
1 2 <b
1 2 !<b
runs
1 2 =b
1 2 !=b
runs
.Ed
.Sh SEE ALSO
.opsy OpenBSD manpages:
.Xr dc 1
.Sh AUTHORS
.An -nosplit
.Xr ohazot oh |
.Xr about oh |
.Lk https://ohazot.com ohazot.com
.Aq Mt admin@ohazot.com