ZSH: calc function

.zshrc

@@ -173,3 +173,20 @@ alias gcf="git commit --fixup=@"
 alias ga="git add"
 alias gp="git push"
 
+# Simple calculator
+function calc() {
+        local 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"
+}