merge branch "improve robustness/portability 💪" into dev-2.x :

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

bin/a2l

@@ -1,6 +1,6 @@
 #!/bin/bash
 # @Function
-# echo each arguments on one line colorfully.
+# print each arguments on one line colorfully.
 #
 # @Usage
 #   $ ./a2l arg1 arg2
@@ -19,26 +19,22 @@ readonly PROG_VERSION='2.5.0-dev'
 # util functions
 ################################################################################
 
-# NOTE: $'foo' is the escape sequence syntax of bash
-readonly ec=$'\033'      # escape char
-readonly eend=$'\033[0m' # escape end
-
-colorEcho() {
+colorPrint() {
   local color="$1"
   shift
   # check isatty in bash https://stackoverflow.com/questions/10022323
   # if stdout is console, turn on color output.
-  [ -t 1 ] && echo "${ec}[1;${color}m$*${eend}" || echo "$*"
-}
-
-redEcho() {
-  colorEcho 31 "$@"
+  if [ -t 1 ]; then
+    printf "\033[1;${color}m%s\033[0m\n" "$*"
+  else
+    printf '%s\n' "$*"
+  fi
 }
 
 usage() {
   cat <<EOF
 Usage: ${PROG} [OPTION]... ARG...
-echo each arguments on one line colorfully.
+print each arguments on one line colorfully.
 
 Example:
   ${PROG} arg1 arg2
@@ -53,7 +49,7 @@ EOF
 }
 
 progVersion() {
-  echo "$PROG $PROG_VERSION"
+  printf '%s\n' "$PROG $PROG_VERSION"
   exit
 }
 
@@ -94,20 +90,20 @@ readonly args
 # biz logic
 ################################################################################
 
-readonly -a ECHO_COLORS=(33 35 36 31 32 37 34)
+readonly -a ROTATE_COLORS=(33 35 36 31 32 37 34)
 COUNT=0
-rotateColorEcho() {
+rotateColorPrint() {
   local message="$*"
 
   # skip color for white space
   if [[ "$message" =~ ^[[:space:]]*$ ]]; then
-    echo "$message"
+    printf '%s\n' "$message"
   else
-    local color="${ECHO_COLORS[COUNT++ % ${#ECHO_COLORS[@]}]}"
-    colorEcho "$color" "$*"
+    local color="${ROTATE_COLORS[COUNT++ % ${#ROTATE_COLORS[@]}]}"
+    colorPrint "$color" "$*"
   fi
 }
 
 for a in ${args[@]:+"${args[@]}"}; do
-  rotateColorEcho "$a"
+  rotateColorPrint "$a"
 done

bin/ap

@@ -21,25 +21,24 @@ readonly PROG_VERSION='2.5.0-dev'
 # util functions
 ################################################################################
 
-# 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
-
-colorEcho() {
+colorPrint() {
   local color="$1"
   shift
   # check isatty in bash https://stackoverflow.com/questions/10022323
   # if stdout is console, turn on color output.
-  [ -t 1 ] && echo "${ec}[1;${color}m$*${eend}" || echo "$*"
+  if [ -t 1 ]; then
+    printf "\033[1;${color}m%s\033[0m\n" "$*"
+  else
+    printf '%s\n' "$*"
+  fi
 }
 
-redEcho() {
-  colorEcho 31 "$@"
+redPrint() {
+  colorPrint 31 "$*"
 }
 
 die() {
-  redEcho "Error: $*" 1>&2
+  redPrint "Error: $*" >&2
   exit 1
 }
 
@@ -54,10 +53,15 @@ portableReadLink() {
     readlink -f "$file"
     ;;
   Darwin*)
+    local py_args=(-c 'import os, sys; print(os.path.realpath(sys.argv[1]))' "$file")
     if command -v greadlink >/dev/null; then
       greadlink -f "$file"
+    elif command -v python3 >/dev/null; then
+      python3 "${py_args[@]}"
+    elif command -v python >/dev/null; then
+      python "${py_args[@]}"
     else
-      python -c 'import os, sys; print(os.path.realpath(sys.argv[1]))' "$file"
+      die "fail to find command(greadlink/python3/python) to get absolute path!"
     fi
     ;;
   *)
@@ -72,10 +76,12 @@ usage() {
   # shellcheck disable=SC2015
   [ "$exit_code" != 0 ] && local -r out=/dev/stderr || local -r out=/dev/stdout
 
-  (($# > 0)) && redEcho "$*$nl" >$out
+  # NOTE: $'foo' is the escape sequence syntax of bash
+  local nl=$'\n' # new line
+  (($# > 0)) && redPrint "$*$nl" >$out
 
   cat >$out <<EOF
-Usage: ${PROG} [OPTION]... ARG...
+Usage: ${PROG} [OPTION]... [FILE]...
 convert to Absolute Path.
 
 Example:
@@ -91,7 +97,7 @@ EOF
 }
 
 progVersion() {
-  echo "$PROG $PROG_VERSION"
+  printf '%s\n' "$PROG $PROG_VERSION"
   exit
 }
 
@@ -115,7 +121,6 @@ while [ $# -gt 0 ]; do
     ;;
   -*)
     usage 2 "${PROG}: unrecognized option '$1'"
-    break
     ;;
   *)
     # if not option, treat all follow files as args
@@ -128,10 +133,20 @@ done
 [ ${#files[@]} -eq 0 ] && files=(.)
 readonly files
 
+################################################################################
+# biz logic
+################################################################################
+
+has_error=false
+
 for f in "${files[@]}"; do
-  ! [ -e "$f" ] && {
-    echo "$f does not exists!"
-    continue
-  }
-  portableReadLink "$f"
+  if [ -e "$f" ]; then
+    portableReadLink "$f"
+  else
+    redPrint "error: $f does not exists!" >&2
+    has_error=true
+  fi
 done
+
+# set exit status
+! $has_error

bin/c

@@ -35,12 +35,14 @@ readonly PROG_VERSION='2.5.0-dev'
 # util functions
 ################################################################################
 
-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 "$*"
+printErrorMsg() {
+  # check isatty in bash https://stackoverflow.com/questions/10022323
+  # if stdout is console, print with red color.
+  if [ -t 1 ]; then
+    printf "\033[1;31m%s\033[0m\n\n" "Error: $*"
+  else
+    printf '%s\n\n' "Error: $*"
+  fi
 }
 
 usage() {
@@ -49,7 +51,7 @@ usage() {
   # shellcheck disable=SC2015
   [ "$exit_code" != 0 ] && local -r out=/dev/stderr || local -r out=/dev/stdout
 
-  (($# > 0)) && redEcho "$*$nl" >$out
+  (($# > 0)) && printErrorMsg "$*" >$out
 
   cat >$out <<EOF
 Usage: ${PROG} [OPTION]... [command [command_args ...]]
@@ -73,7 +75,7 @@ EOF
 }
 
 progVersion() {
-  echo "$PROG $PROG_VERSION"
+  printf '%s\n' "$PROG $PROG_VERSION"
   exit
 }
 
@@ -106,7 +108,7 @@ while [ $# -gt 0 ]; do
     break
     ;;
   -*)
-    usage 2 "${PROG}: unrecognized option '$1'"
+    usage 2 "unrecognized option '$1'"
     ;;
   *)
     # if not option, treat all follow args as command

bin/coat

@@ -15,26 +15,22 @@ set -eEuo pipefail
 #   check isatty in bash https://stackoverflow.com/questions/10022323
 [ ! -t 1 ] && exec cat "$@"
 
-# NOTE: $'foo' is the escape sequence syntax of bash
-readonly ec=$'\033'      # escape char
-readonly eend=$'\033[0m' # escape end
-
-readonly -a ECHO_COLORS=(33 35 36 31 32 37 34)
+readonly -a ROTATE_COLORS=(33 35 36 31 32 37 34)
 COUNT=0
-rotateColorEcho() {
+rotateColorPrint() {
   local message="$*"
 
   # skip color for white space
   if [[ "$message" =~ ^[[:space:]]*$ ]]; then
-    echo "$message"
+    printf '%s\n' "$message"
   else
-    local color="${ECHO_COLORS[COUNT++ % ${#ECHO_COLORS[@]}]}"
-    echo "${ec}[1;${color}m$message$eend"
+    local color="${ROTATE_COLORS[COUNT++ % ${#ROTATE_COLORS[@]}]}"
+    printf "\033[1;${color}m%s\033[0m\n" "$message"
   fi
 }
 
 # Bash read line does not read leading spaces
 # https://stackoverflow.com/questions/29689172
 cat "$@" | while IFS= read -r line; do
-  rotateColorEcho "$line"
+  rotateColorPrint "$line"
 done

bin/cp-into-docker-run

@@ -17,18 +17,17 @@ readonly PROG_VERSION='2.5.0-dev'
 # util functions
 ################################################################################
 
-# 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() {
+redPrint() {
   # -t check: is a terminal device?
-  [ -t 1 ] && echo "${ec}[1;31m$*$eend" || echo "$*"
+  if [ -t 1 ]; then
+    printf "\033[1;31m%s\033[0m\n" "$*"
+  else
+    printf '%s\n' "$*"
+  fi
 }
 
 die() {
-  redEcho "Error: $*" 1>&2
+  redPrint "Error: $*" 1>&2
   exit 1
 }
 
@@ -47,10 +46,15 @@ portableReadLink() {
     readlink -f "$file"
     ;;
   Darwin*)
+    local py_args=(-c 'import os, sys; print(os.path.realpath(sys.argv[1]))' "$file")
     if command -v greadlink >/dev/null; then
       greadlink -f "$file"
+    elif command -v python3 >/dev/null; then
+      python3 "${py_args[@]}"
+    elif command -v python >/dev/null; then
+      python "${py_args[@]}"
     else
-      python -c 'import os, sys; print(os.path.realpath(sys.argv[1]))' "$file"
+      die "fail to find command(greadlink/python3/python) for readlink!"
     fi
     ;;
   *)
@@ -65,7 +69,9 @@ usage() {
   # shellcheck disable=SC2015
   [ "$exit_code" != 0 ] && local -r out=/dev/stderr || local -r out=/dev/stdout
 
-  (($# > 0)) && redEcho "$*$nl" >$out
+  # NOTE: $'foo' is the escape sequence syntax of bash
+  local nl=$'\n' # new line
+  (($# > 0)) && redPrint "$*$nl" >$out
 
   cat >$out <<EOF
 Usage: ${PROG} [OPTION]... command [command-args]...
@@ -100,7 +106,7 @@ EOF
 }
 
 progVersion() {
-  echo "$PROG $PROG_VERSION"
+  printf '%s\n' "$PROG $PROG_VERSION"
   exit
 }
 
@@ -235,7 +241,7 @@ trap cleanupWhenExit EXIT
 ########################################
 
 logAndRun() {
-  $verbose && echo "[$PROG] $*" 1>&2
+  $verbose && printf '%s\n' "[$PROG] $*" 1>&2
   "$@"
 }
 

bin/echo-args

@@ -6,20 +6,37 @@
 # @author Jerry Lee (oldratlee at gmail dot com)
 set -eEuo pipefail
 
-readonly ec=$'\033'      # escape char
-readonly eend=$'\033[0m' # escape end
+digitCount() {
+  # argument 1(num) is always a non-negative integer in this script usage,
+  # so NO argument validation logic.
+  local num="$1" count=0
+  while ((num != 0)); do
+    ((++count))
+    ((num = num / 10))
+  done
+  echo "$count"
+}
+
+digit_count=$(digitCount $#)
+readonly arg_count=$# digit_count
+
+readonly red='\033[1;31m'
+readonly blue='\033[1;36m'
+readonly normal='\033[0m'
 
-echoArg() {
-  local index="$1" count="$2" value="$3"
+printArg() {
+  local idx="$1" value="$2"
 
   # if stdout is console, turn on color output.
-  [ -t 1 ] &&
-    echo "${index}/${count}: ${ec}[1;31m[$eend${ec}[1;36;40m$value$eend${ec}[1;31m]$eend" ||
-    echo "${index}/${count}: [${value}]"
+  if [ -t 1 ]; then
+    printf "%${digit_count}s/%s: ${red}[${blue}%s${red}]${normal}\n" "$idx" "$arg_count" "$value"
+  else
+    printf "%${digit_count}s/%s: [%s]\n" "$idx" "$arg_count" "$value"
+  fi
 }
 
-echoArg 0 $# "$0"
+printArg 0 "$0"
 idx=1
 for a; do
-  echoArg $((idx++)) $# "$a"
+  printArg $((idx++)) "$a"
 done