d stands for data. d-rs is a combination of features from grep, awk sed, and other unix tools, to easily edit piped data.

How to use

Let's say a file exists with the following contents:

# Hours

x: 3 hours
y: 3.5 hours
z: 15 hours
w: 1.5 hours

You can use d to find how many hours there are in total with:

cat hours.txt | d f float | d r sum

Gives 23.

So what happened here?

d has 4 main subcommands

• filter (or find, it's pretty much the same operation for d)
• map
• reduce
• split

Each of the commands can be abbreviated (by f, m, r or s respectively).

So what happened in the example? first we find all the floats, then we reduce using the sum operator.

In general, you can

• find things using custom or a number of built-in regexes
• map things using custom or a number of built-in regexes, or a python expression (more may come)
• reduce things using the sum, product or join operators (more may come)
• split things based on a single character or word (no regexes supported yet)

python mapping

using d m p (d map python) you can tell d to run a line of python for every line in the input. Your line will be ran in a context where:

• There is an i or inp variable available which contains the current line
• There is an o or out variable which when written to becomes the result of the expression (using __repr__ to convert it to a string)
• Alternatively, you can print the result of your expression. If you do, the values in o/out are ignored, to prevent multiple outputs from the expression.

No state is kept between mapping lines.

TODO list

• more built-in regexes
• finding commonly used units (for example, disk sizes in the format 500KiB) and automatically convert to their base units (500Kib --> 512000)
• built-in n-to-m base conversion