fix(user/bkdatev):Make compatible with Bash 3.2.57

- Note: In Bash 5.1, a negative length argument in a parameter
  substitution (i.e. the `$len` in `${myVar:$start_idx:$len}`) causes
  the last characters of the $myVar string to be truncated which is
  convenient in various applications. However, a negative length in Bash
  3.2.57 (a macOS machine I happen to have) throws an error; for
  compatibility, I've instead added an additional arithemetical
  operation to calculate the positive length that corresponds to a
  truncation by 2 of the total string length.

diff --git a/user/bkdatev b/user/bkdatev
old mode 100755 (executable)
new mode 100644 (file)
index f2f92ec..3cc96d9
--- a/user/bkdatev
+++ b/user/bkdatev
@@ -2,7 +2,7 @@
 # Desc: Baltakatei's verbose date command
 # Usage: bkdatev [args]
 # Example: bkdatev --date="2001-09-11T09:02:59-04"
-# Version: 0.3.0
+# Version: 0.3.1
 # Ref/Attrib: [1] "ISO 8601". Wikipedia. https://en.wikipedia.org/wiki/ISO_8601
 #             [2] "Changing the Locale in Wine" https://stackoverflow.com/a/16428951
 #             [3] "Shanghai vs Beijing" https://bugs.launchpad.net/ubuntu/+source/libgweather/+bug/228554
@@ -83,7 +83,9 @@ get_tz_offset() {
     #last2="$(rev <<< $ntz)" && last2="${last2:0:2}" && last2="$(rev <<< "$last2")";
     if [[ "$last2" == "00" ]]; then
         ## ntz_out is truncated by 2 characters
-        ntz_out="${ntz:0:-2}";
+       len_ntz="${#ntz}";
+       len_ntz_out="$(( len_ntz - 2 ))";
+       ntz_out=""${ntz:0:$len_ntz_out};
     else
         ## ntz_out is ntz with semicolon inserted after HH
         ntz_out="$(insertStr "$ntz" 3 ":" )";