Add 'math', 'roll', and 'sum' programs

README.md

@@ -181,6 +181,16 @@ lwjgl-fix
 ---
 On Arch Linux, fix lwjgl.jar in minecraft
 
+math
+---
+CLI calculator. Outputs the result of simple math expresisons. Example:
+
+    math 2+2
+
+Outputs:
+
+    2+2 = 4
+
 markov
 ---
 Markov-chain input on a per-word basis
@@ -292,6 +302,18 @@ retry
 ---
 Retry a command 5 times or until it succeeds
 
+roll
+---
+Rolls D&D dice.
+
+Usage:
+
+    roll "d6 + 4"
+
+Output:
+
+    1d6+4 = 8
+
 rtmux
 ---
 
@@ -346,6 +368,10 @@ static-ip
 ---
 Set up a static ip on linux
 
+sum
+---
+Adds a list of numbers, one per line.
+
 tag_images
 ---
 Tag images in a directory interactively, using 'feh'. One button resizes, another tags the image using an interactive program. I use this for processing scanned images.

math

@@ -0,0 +1,4 @@
+#!/usr/bin/env python
+import sys
+s = "".join(sys.argv[1:])
+print(s, "=", eval(s))

roll

@@ -0,0 +1,29 @@
+#!/usr/bin/env python3
+import random, re, sys
+s = "".join(sys.argv[1:]).replace(" ", "")
+
+REGEX = "(\d*)d(\d+)([-+]\d+)?"
+m = re.match(REGEX, s)
+if m:
+    dice, sides, modifier = m.group(1), m.group(2), m.group(3)
+    if dice:
+        dice = int(dice)
+    else:
+        dice = 1
+    sides = int(sides)
+    if modifier and modifier.startswith("+"):
+        modifier = int(modifier[1:])
+    elif modifier and modifier.startswith("-"):
+        modifier = int(modifier)
+    else:
+        modifier = 0
+    result = modifier
+    for i in range(sides):
+        result += random.randint(1, sides)
+    if modifier >= 0:
+        s = "{}d{}+{}".format(dice, sides, modifier)
+    else:
+        s = "{}d{}{}".format(dice, sides, modifier)
+    print(s, "=", result)
+else:
+    print(s, "INVALID")

sum

@@ -0,0 +1,2 @@
+#!/bin/sh
+paste -sd+ - | bc