feat(user/mc_distance_calc.sh):Add minecraft distance calculator

diff --git a/user/mc_distance_calc.sh b/user/mc_distance_calc.sh
new file mode 100755 (executable)
index 0000000..4666d66
--- /dev/null
+++ b/user/mc_distance_calc.sh
@@ -0,0 +1,69 @@
+#!/usr/bin/env bash
+# Desc: Calculates distances between two minecraft coordinates
+# Depends: bash 5.1.16, bc 1.07.1
+# Depends: BK-2020-03: yell(), die(), must()
+# Version: 0.0.2
+# Example: script.sh 0 0 0 1 1 1
+#   Note: results in xyz distance of 1.73205…
+
+yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
+die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
+must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
+checkFlt() {
+    # Desc: Checks if arg is a float
+    # Usage: checkFlt arg
+    # Input: arg: float
+    # Output: - return code 0 (if arg is float)
+    #         - return code 1 (if arg is not float)
+    # Example: if ! checkFlt $arg; then echo "not flt"; fi;
+    # Version: 0.0.2
+    # Depends: yell(), die(), bash 5.0.3
+    # Ref/Attrib: JDB https://stackoverflow.com/a/12643073 float regex
+    local returnState
+
+    #===Process Arg===
+    if [[ $# -ne 1 ]]; then
+       die "ERROR:Invalid number of arguments:$#";
+    fi;
+
+    RETEST1='^[+-]?([0-9]+([.][0-9]*)?|[.][0-9]+)$'; # Regular Expression to test
+    if [[ ! $1 =~ $RETEST1 ]] ; then
+       returnState="false";
+    else
+       returnState="true";
+    fi;
+
+    #===Determine function return code===
+    if [ "$returnState" = "true" ]; then
+       return 0;
+    else
+       return 1;
+    fi;
+} # Checks if arg is float
+main() {
+    x1="$1"; y1="$2"; z1="$3";
+    x2="$4"; y2="$5"; z2="$6";
+    #declare -p x1 y1 z1 x2 y2 z2; # debug
+
+    # Check inputs
+    if ! checkFlt "$x1"; then die "FATAL:Not a float:$x1"; fi;
+    if ! checkFlt "$y1"; then die "FATAL:Not a float:$y1"; fi;
+    if ! checkFlt "$z1"; then die "FATAL:Not a float:$z1"; fi;
+    if ! checkFlt "$x2"; then die "FATAL:Not a float:$x2"; fi;
+    if ! checkFlt "$y2"; then die "FATAL:Not a float:$y2"; fi;
+    if ! checkFlt "$z2"; then die "FATAL:Not a float:$z2"; fi;
+
+    # Calculate distances
+    dist_xyz_eq="sqrt( ($x2 - $x1)^2 + ($y2 - $y1)^2 + ($z2 - $x1)^2 )";
+    dist_xyz="$(printf "%s\n" "$dist_xyz_eq" | bc -l;)";
+    #declare -p dist_xyz_eq dist_xyz; # debug
+    
+    dist_xz_eq=" sqrt( ($x2 - $x1)^2 + ($z2 - $z1)^2 ) ";
+    dist_xz="$(printf "%s\n" "$dist_xz_eq" | bc -l;)";
+    declare -p dist_xz_eq dist_xz; # debug
+
+    printf "dist_xyz:%s\n" "$dist_xyz";
+    printf "dist_xz:%s\n" "$dist_xz";
+}; # Main program
+
+main "$@";