add calc script

1 files changed, 16 insertions, 0 deletions

diff --git a/calc b/calc
new file mode 100755
index 0000000..d307962
--- /dev/null
+++ b/calc
@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+# Simple calculator
+result=""
+result="$(printf "scale=10;$*\n" | bc --mathlib | tr -d '\\\n')"
+#                       └─ default (when `--mathlib` is used) is 20
+#
+if [[ "$result" == *.* ]]; then
+  # improve the output for decimal numbers
+  printf "$result" |
+  sed -e 's/^\./0./'        `# add "0" for cases like ".5"` \
+      -e 's/^-\./-0./'      `# add "0" for cases like "-.5"`\
+      -e 's/0*$//;s/\.$//'   # remove trailing zeros
+else
+  printf "$result"
+fi
+printf "\n"