## Send commands to `dc`

The `dc` function reads the current line into `dc`, sends the commands to `dc`, and replaces the current line with the stack from `dc`.
If the current line does not exist, the `dc` function sends the commands to `dc` and reads the stack from `dc` into the buffer.

Suppose that the current line is:

    1 2 3 4

The command `<dc +*+` changes the line to:

    15

    # Send commands to dc.
    # usage: <dc [commands]
    function:dc {
    db0
    H-
    ebvar-
    X
    if(*) {
    # Prepare negative numbers for dc.
    s/\(^\|\s+\)-\(\d*\.?\d*\)/$1_$2/gf
    .W !echo $(dc -e "? ~0 f" | tac)
    } else {
    r !echo $(dc -e "~0 f" | tac)
    }
    }

## Send each number on a line to `dc` separately

If the current line contains 1 or more numbers, for each number, the `ldc` function reads the number into `dc`, sends the commands to `dc`, and replaces the number with the stack from `dc`.
If the current line does not contain a number, the `ldc` function sends the commands to `dc` and reads the stack from `dc` into the buffer.

Suppose that the current line is:

    1 2 3 4

The command `<ldc 1 + 2 ^` changes the line to:

    4 9 16 25

    # Send each number on a line separately to dc.
    # usage: <ldc [commands]
    # This function uses the labels y and z.
    function:ldc {
    db0
    H-
    ebvar-
    # Check whether the current line contains a number.
    s/\d/&/f
    if(*) {
    -X
    if(*) {
    ky
    +X
    s/-?\d*\.?\d+/\n&\n/gf
    kz
    'y+,'zg/\d/f s/^-/_/f
    'y+,'zg/\d/f .W !echo $(dc -e "? ~0 f" | tac)
    'y+,'zj
    } else {
    s/-?\d*\.?\d+/\n&\n/gf
    kz
    1,'zg/\d/f s/^-/_/f
    1,'zg/\d/f .W !echo $(dc -e "? ~0 f" | tac)
    1,'zj
    }
    } else {
    r !echo $(dc -e "~0 f" | tac)
    }
    p
    }

## Send commands to dc and count the numbers on the stack

If the current line exists, the `count` function reads the line into `dc`, sends the commands to `dc`, and replaces the current line with the count of the `dc` stack.
If the current line does not exist, the `count` function sends the commands to `dc` and reads the count of the `dc` stack into the buffer.

Suppose that the current line is:

    1 2 3 4

The command `<count` changes the line to:

    4

    # After executing any dc commands, count the numbers on the stack 
    # usage: <count [commands]
    function+count {
    <dc ~0 zSacLa
    }

## Send commands to dc and calculate the sum of the numbers on the stack

If the current line exists, the `sum` function reads the line into `dc`, sends the commands to `dc`, and replaces the current line with the sum of the `dc` stack.
If the current line does not exist, the `sum` function sends the commands to `dc` and reads the sum of the `dc` stack into the buffer.

Suppose that the current line is:

    1 2 3 4

The command `<sum` changes the line to:

    10

    # After executing any dc commands, calculate the sum of the numbers on the stack 
    # usage: <sum [commands]
    function+sum {
    <dc ~0 [+2z>a]sa2z>a
    }

## Send commands to dc and calculate the mean of the numbers on the stack

If the current line exists, the `mean` function reads the line into `dc`, sends the commands to `dc`, and replaces the current line with the mean of the `dc` stack.
If the current line does not exist, the `mean` function sends the commands to `dc` and reads the mean of the `dc` stack into the buffer.

Suppose that the current line is:

    1 2 3 4

The command `<mean 2k` changes the line to:

    2.50

(The `2k` command changed the precision to 2.)

    # After executing any dc commands, calculate the mean of the numbers on the stack 
    # usage: <mean [commands]
    # Use a command like 3k to set the precision to 3.
    function+mean {
    <dc ~0 [+2z>b]sb[zSa2z>bLa/]sc1z>c
    }

## Send commands to dc and calculate the precision-controlled product of the numbers on the stack

If the current line exists, the `kproduct` function reads the line into `dc`, sends the commands to `dc`, and replaces the current line with the precision-controlled product of the `dc` stack.
If the current line does not exist, the `kproduct` function sends the commands to `dc` and reads the precision-controlled product of the `dc` stack into the buffer.

Suppose that the current line is:

    1.1 2.2 3.3 4.4

The command `<kproduct 2k` changes the line to:

    35.13

    # After executing any dc commands, calculate the precision-controlled product of the numbers on the stack 
    # usage: <kproduct [commands]
    # Use a command like 3k to set the precision to 3.
    function+kproduct {
    <dc ~0 [*2z>a]sa2z>a
    }

## Send commands to dc and calculate the product of the numbers on the stack

If the current line exists, the `product` function reads the line into `dc`, sends the commands to `dc`, and replaces the current line with the product of the `dc` stack.
If the current line does not exist, the `product` function sends the commands to `dc` and reads the product of the `dc` stack into the buffer.

Suppose that the current line is:

    1.1 2.2 3.3 4.4

The command `<product` changes the line to:

    35.1384

    # After executing any dc commands, calculate the product of the numbers on the stack 
    # usage: <product [commands]
    function+product {
<dc ~0 [SadXlaX+kLa*2z>b]sb2z>b
    }

## Send commands to dc and calculate the maximum of the numbers on the stack

If the current line exists, the `max` function reads the line into `dc`, sends the commands to `dc`, and replaces the current line with the maximum of the `dc` stack.
If the current line does not exist, the `max` function sends the commands to `dc` and reads the maximum of the `dc` stack into the buffer.

Suppose that the current line is:

    1 2 3 4

The command `<max` changes the line to:

    4

    # After executing any dc commands, calculate the maximum of the numbers on the stack 
    # usage: <max [commands]
    function+max {
    <dc ~0 [sala]sc[dla<csb1z>d]sd[sa1z>dla]se1z>e
    }

## Send commands to dc and calculate the minimum of the numbers on the stack

If the current line exists, the `min` function reads the line into `dc`, sends the commands to `dc`, and replaces the current line with the minimum of the `dc` stack.
If the current line does not exist, the `min` function sends the commands to `dc` and reads the minimum of the `dc` stack into the buffer.

Suppose that the current line is:

    1 2 3 4

The command `<min` changes the line to:

    1

    # After executing any dc commands, calculate the minimum of the numbers on the stack 
    # usage: <min [commands]
    function+min {
    <dc ~0 [sala]sc[dla>csb1z>d]sd[sa1z>dla]se1z>e
    }