From 206d940e798d3f4d6f3ac54c91e2e4784b70bb3f Mon Sep 17 00:00:00 2001
From: Akemi Izuko <akemi@noway.moe>
Date: Mon, 10 Oct 2022 20:09:07 -0600
Subject: [PATCH] Add 'runk' calculator function

---
 bash/.bash_functions | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/bash/.bash_functions b/bash/.bash_functions
index 7040de0..a0f6a2e 100644
--- a/bash/.bash_functions
+++ b/bash/.bash_functions
@@ -57,6 +57,38 @@ viw() {
   fi
 }
 
+# Ronald's Universal Number Kruncher, standardized syntax for unix calculators
+# Syntax features:
+#   ^ and ** both work for exponentiation
+#   log()  is base 10
+#   ln()   is base e
+#   log2() is base 2
+# Careful when changing order or sed might sed itself!
+runk() {
+  local calc_ver="$(echo "$@" | sed \
+    -e 's#log2(\([^)]\+\))#(log(\1)/log(2))#g' \
+  )"
+  local py_ver="$(echo "$@" | sed \
+    -e 's#\^#**#g' \
+    -e 's#\(log([^)]\+)\)#(\1/log(10))#g' \
+    -e 's#ln(\([^)]\+\))#log(\1)#g' \
+  )"
+  local bc_ver="$(echo "$@" | sed \
+    -e 's#\*\*#^#g' \
+    -e 's#ln(\([^)]\+\))#l(\1)#g' \
+    -e 's#log(\([^)]\+\))#(l(\1)/l(10))#g' \
+    -e 's#log2(\([^)]\+\))#(l(\1)/l(2))#g' \
+  )"
+
+  if command -v calc &>/dev/null; then
+    calc "$calc_ver"
+  elif command -v python3 &>/dev/null; then
+    python3 -c "from math import *; print($py_ver)"
+  else
+    echo "$bc_ver" | bc --mathlib
+  fi
+}
+
 # Better exiting ====================================================
 # Don't exit with background jobs still running. Particularly for Qemu
 function exit () {