refactor/robust(uq): use printf 💪 instead of echo; use `if-else…

…` instead of `&&-||`; use `${var#}` instead of `awk`

NOTE:

- the `echo` option(e.g. -e -n) may effect correctness, `printf` is more robust 💪
- about `&&-||` see shell check:
  https://www.shellcheck.net/wiki/SC2015

bin/uq

@@ -38,20 +38,28 @@ readonly PROG_VERSION='2.5.0-dev'
 ################################################################################
 
 # NOTE: $'foo' is the escape sequence syntax of bash
-readonly ec=$'\033'      # escape char
-readonly eend=$'\033[0m' # escape end
-readonly nl=$'\n'        # new line
-
-redEcho() {
-  [ -t 1 ] && echo "${ec}[1;31m$*$eend" || echo "$*"
+readonly nl=$'\n' # new line
+
+redPrint() {
+  # -t check: is a terminal device?
+  if [ -t 1 ]; then
+    printf "\033[1;31m%s\033[0m\n" "$*"
+  else
+    printf '%s\n' "$*"
+  fi
 }
 
-yellowEcho() {
-  [ -t 1 ] && echo "${ec}[1;33m$*$eend" || echo "$*"
+yellowPrint() {
+  # -t check: is a terminal device?
+  if [ -t 1 ]; then
+    printf "\033[1;33m%s\033[0m\n" "$*"
+  else
+    printf '%s\n' "$*"
+  fi
 }
 
 die() {
-  redEcho "Error: $*" 1>&2
+  redPrint "Error: $*" 1>&2
   exit 1
 }
 
@@ -82,7 +90,7 @@ usage() {
   # shellcheck disable=SC2015
   [ "$exit_code" != 0 ] && local -r out=/dev/stderr || local -r out=/dev/stdout
 
-  (($# > 0)) && redEcho "$*$nl" >$out
+  (($# > 0)) && redPrint "$*$nl" >$out
 
   cat >$out <<EOF
 Usage: ${PROG} [OPTION]... [INPUT [OUTPUT]]
@@ -121,7 +129,7 @@ EOF
 }
 
 progVersion() {
-  echo "$PROG $PROG_VERSION"
+  printf '%s\n' "$PROG $PROG_VERSION"
   exit
 }
 
@@ -156,7 +164,7 @@ while (($# > 0)); do
   --all-repeated=*)
     uq_opt_all_repeated=1
 
-    uq_opt_repeated_method=$(echo "$1" | awk -F= '{print $2}')
+    uq_opt_repeated_method=${1#--all-repeated=}
     [[ $uq_opt_repeated_method == 'none' || $uq_opt_repeated_method == 'prepend' || $uq_opt_repeated_method == 'separate' ]] ||
       usage 1 "$PROG: invalid argument ‘${uq_opt_repeated_method}’ for ‘--all-repeated’${nl}Valid arguments are:$nl  - ‘none’$nl  - ‘prepend’$nl  - ‘separate’"
 
@@ -209,7 +217,7 @@ done
   usage 2 "printing all duplicate lines(-D, --all-repeated) and unique lines(-u, --unique) is meaningless"
 
 [[ $uq_opt_all_repeated == 1 && $uq_opt_repeated_method == none && ($uq_opt_count == 0 && $uq_opt_only_repeated == 0) ]] &&
-  yellowEcho "[$PROG] WARN: -D/--all-repeated=none option without -c/-d option, just cat input simply!" >&2
+  yellowPrint "[$PROG] WARN: -D/--all-repeated=none option without -c/-d option, just cat input simply!" >&2
 
 # NOTE: DO NOT declare var uq_max_input_size as readonly in ONE line!
 uq_max_input_size="$(convertHumanReadableSizeToSize "$uq_max_input_human_readable_size")" ||