feat(unitproc/bkt-get_path_fork_level):Add Bash function

diff --git a/unitproc/bkt-get_path_fork_level b/unitproc/bkt-get_path_fork_level
new file mode 100755 (executable)
index 0000000..521b42d
--- /dev/null
+++ b/unitproc/bkt-get_path_fork_level
@@ -0,0 +1,74 @@
+#!/bin/bash
+
+get_path_fork_level() {
+    # Desc: Get fork level from two paths
+    # Input:  arg1    str  path
+    #         arg2    str  path
+    # Output: stdout  int  fork level
+    # Version: 0.0.1
+    local path1="$1";
+    local path2="$2";
+
+    # Squeeze multiple slashes and remove trailing slashes
+    path1="$(echo "$path1" | tr -s '/' | sed 's:/*$::' )";
+    path2="$(echo "$path2" | tr -s '/' | sed 's:/*$::' )";
+    
+    # Check for mixed absolute/relative paths
+    if [[ "$path1" =~ ^/ ]] && [[ "$path2" =~ ^/ ]]; then
+        flag_root=true;
+        # Remove initial /
+        path1="$(echo "$path1" | sed -e 's:^/::' )";
+        path2="$(echo "$path2" | sed -e 's:^/::' )";
+    elif [[ ! "$path1" =~ ^/ ]] && [[ ! "$path2" =~ ^/ ]]; then
+        flag_root=false;
+    else
+        declare -p path1 path2 flag_root;
+        echo "FATAL:Mixed relative and absolute paths not supported." 1>&2;
+        return 1;
+    fi;
+
+    # Save path as arrays with `/` as element delimiter
+    local IFS='/';
+    read -ra parts1 <<< "$path1";
+    read -ra parts2 <<< "$path2";
+
+    # Get fork level by counting identical path elements from rootside
+    local fork_level=0;
+    for (( i=0; i<${#parts1[@]} && i<${#parts2[@]}; i++ )); do
+        if [[ "${parts1[i]}" != "${parts2[i]}" ]]; then break; fi;
+        ((fork_level++));
+    done;
+    
+    echo "$fork_level";
+    #declare -p path1 path2 flag_root parts1 parts2 fork_level; # debug
+    return 0;
+}; # Get fork level int from two paths
+
+printf "========Test 1========\n";  # fork at 0
+p1="foo"; p2="bee"; declare -p p1 p2;
+get_path_fork_level "$p1" "$p2";
+printf "========Test 2========\n";  # fork at 1
+p1="foo"; p2="foo/bar"; declare -p p1 p2;
+get_path_fork_level "$p1" "$p2";
+printf "========Test 3========\n";  # fork at 1
+p1="foo"; p2="foo/bar/"; declare -p p1 p2;
+get_path_fork_level "$p1" "$p2";
+printf "========Test 4========\n";  # fork at 2
+p1="foo/bar/baz"; p2="foo/bar"; declare -p p1 p2;
+get_path_fork_level "$p1" "$p2";
+printf "========Test 5========\n";  # fork at 2
+p1="/foo/bar/baz"; p2="/foo/bar"; declare -p p1 p2;
+get_path_fork_level "$p1" "$p2";
+printf "========Test 6========\n";  # ERROR: No mixed
+p1="foo/bar/baz"; p2="/bee/boo/tax"; declare -p p1 p2;
+get_path_fork_level "$p1" "$p2";
+printf "========Test 7========\n";  # fork at 0
+p1="/foo/bar/baz"; p2="/bee/boo/tax"; declare -p p1 p2;
+get_path_fork_level "$p1" "$p2";
+printf "========Test 8========\n";  # # ERROR: No mixed
+p1="/foo/bar/baz"; p2="foo"; declare -p p1 p2;
+get_path_fork_level "$p1" "$p2";
+printf "========Test 9========\n";  # fork at 3
+p1="foo///////////bar////////baz//////"; p2="foo/////////bar/////////baz///bee"; declare -p p1 p2;
+get_path_fork_level "$p1" "$p2";
+