Make this project POSIX Compliant.

[calebe94]

Expected Behavior

Make this project POSIX Compliant.

• ShellCheck – shell script analysis tool ;
• 24 Bashism To Avoid for POSIX-Compliant Shell Scripts;
• POSIX compliant shell scripting - HLRS Platforms
• GitHub - koalaman/shellcheck: ShellCheck, a static analysis tool for shell scripts

Current Behavior

Log from shellcheck:

In tmenu line 29:
if [ ! -d "`dirname "$CACHE"`" ]; then
           ^----------------^ SC2006: Use $(...) notation instead of legacy backticked `...`.

Did you mean: 
if [ ! -d "$(dirname "$CACHE")" ]; then


In tmenu line 34:
	if stest -dqr -n "$CACHE" $PATH; then
                                  ^---^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
	if stest -dqr -n "$CACHE" "$PATH"; then


In tmenu line 35:
		stest -flx $PATH | sort -u > "$CACHE"
                           ^---^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
		stest -flx "$PATH" | sort -u > "$CACHE"


In tmenu line 47:
  sub_item="$($TYAML_COMMAND -k $current_path)"
                                ^-----------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
  sub_item="$($TYAML_COMMAND -k "$current_path")"


In tmenu line 51:
    command="$($TYAML_COMMAND -v $current_path)"
                                 ^-----------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    command="$($TYAML_COMMAND -v "$current_path")"


In tmenu line 52:
    if [ -z "$command" ] && [ ! -z "$selected_tag" ]; then
                              ^-- SC2236: Use -n instead of ! -z.


In tmenu line 54:
    elif [ "${command[@]}" != "null" ]; then
           ^-------------^ SC2198: Arrays don't work as operands in [ ]. Use a loop (or concatenate with * instead of @).


In tmenu line 65:
    $TYAML_COMMAND -k $current_path
                      ^-----------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
    $TYAML_COMMAND -k "$current_path"


In tmenu line 71:
  tag_selected="$(list_items | dmenu -p $menu_prompt)"
                                        ^----------^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
  tag_selected="$(list_items | dmenu -p "$menu_prompt")"

For more information:
  https://www.shellcheck.net/wiki/SC2198 -- Arrays don't work as operands in ...
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...
  https://www.shellcheck.net/wiki/SC2006 -- Use $(...) notation instead of le...

Possible Solution

Steps to Reproduce

Context (Environment)

Detailed Description

Possible Implementation