refactor: declare var as readonly if possible, more info in Google's Shell Style Guide:

oldratlee · oldratlee · commit 9fd82c16ebfc · 2022-01-29T04:32:46.000+08:00
- 常量和环境变量名 https://zh-google-styleguide.readthedocs.io/en/latest/google-shell-styleguide/naming_conventions/#id4 - 只读变量 https://zh-google-styleguide.readthedocs.io/en/latest/google-shell-styleguide/naming_conventions/#id6
diff --git a/bin/a2l b/bin/a2l
@@ -12,6 +12,7 @@ set -eEuo pipefail
 
 # NOTE: DO NOT declare var PROG as readonly, because its value is supplied by subshell.
 PROG="$(basename "$0")"
+readonly PROG
 readonly PROG_VERSION='2.5.0-dev'
 
 ################################################################################
@@ -87,6 +88,8 @@ while [ $# -gt 0 ]; do
     esac
 done
 
+readonly args
+
 ################################################################################
 # biz logic
 ################################################################################
diff --git a/bin/ap b/bin/ap
@@ -14,6 +14,7 @@ set -eEuo pipefail
 
 # NOTE: DO NOT declare var PROG as readonly, because its value is supplied by subshell.
 PROG="$(basename "$0")"
+readonly PROG
 readonly PROG_VERSION='2.5.0-dev'
 
 ################################################################################
@@ -125,6 +126,7 @@ while [ $# -gt 0 ]; do
 done
 
 [ ${#files[@]} -eq 0 ] && files=(.)
+readonly files
 
 for f in "${files[@]}"; do
     ! [ -e "$f" ] && {
diff --git a/bin/c b/bin/c
@@ -22,6 +22,7 @@ set -eEuo pipefail
 
 # NOTE: DO NOT declare var PROG as readonly, because its value is supplied by subshell.
 PROG="$(basename "$0")"
+readonly PROG
 readonly PROG_VERSION='2.5.0-dev'
 
 ################################################################################
@@ -109,6 +110,8 @@ while [ $# -gt 0 ]; do
     esac
 done
 
+readonly eol quiet args
+
 ################################################################################
 # biz logic
 ################################################################################
diff --git a/bin/cp-into-docker-run b/bin/cp-into-docker-run
@@ -10,6 +10,7 @@
 set -eEuo pipefail
 
 PROG="$(basename "$0")"
+readonly PROG
 readonly PROG_VERSION='2.5.0-dev'
 
 ################################################################################
@@ -163,6 +164,8 @@ while (($# > 0)); do
     esac
 done
 
+readonly container_name docker_user docker_workdir docker_tmpdir docker_command_cp_path verbose args
+
 [ -n "$container_name" ] ||
     usage 1 "No destination docker container name, specified by option -c/--container!"
 
@@ -198,6 +201,11 @@ if [ ! -f "$specified_run_command" ]; then
 fi
 run_command="$(portableReadLink "$run_command")"
 run_command_base_name="$(basename "$run_command")"
+readonly run_command run_command_base_name
+
+run_timestamp="$(date "+%Y%m%d_%H%M%S")"
+readonly run_timestamp
+readonly uuid="${PROG}_${run_timestamp}_${$}_${RANDOM}"
 
 if [ -n "${docker_command_cp_path}" ]; then
     if isAbsolutePath "$docker_command_cp_path"; then
@@ -206,9 +214,8 @@ if [ -n "${docker_command_cp_path}" ]; then
         readonly run_command_in_docker="${docker_workdir:+"$docker_workdir/"}$docker_command_cp_path"
     fi
     run_command_dir_in_docker="$(dirname "$run_command_in_docker")"
+    readonly run_command_dir_in_docker
 else
-    run_timestamp="$(date "+%Y%m%d_%H%M%S")"
-    readonly uuid="${PROG}_${run_timestamp}_${$}_${RANDOM}"
     readonly work_tmp_dir_in_docker="$docker_tmpdir/$uuid"
 
     readonly run_command_in_docker="$work_tmp_dir_in_docker/$run_command_base_name"
diff --git a/bin/find-in-jars b/bin/find-in-jars
@@ -27,6 +27,7 @@ set -eEuo pipefail
 
 # NOTE: DO NOT declare var PROG as readonly, because its value is supplied by subshell.
 PROG="$(basename "$0")"
+readonly PROG
 readonly PROG_VERSION='2.5.0-dev'
 
 ################################################################################
@@ -229,12 +230,14 @@ while (($# > 0)); do
     esac
 done
 
+readonly separator regex_mode ignore_case_option use_absolute_path only_print_file_name print_matched_files show_responsive args
+
 # shellcheck disable=SC2178
 dirs=${dirs:-.}
 # shellcheck disable=SC2178
-extensions=${extensions:-jar}
+readonly extensions=${extensions:-jar}
 
-(("${#args[@]}" == 0)) && usage 1 "No find file pattern!"
+(("${#args[@]}" == 0)) && usage 1 "Missing file pattern!"
 (("${#args[@]}" > 1)) && usage 1 "More than 1 file pattern: ${args[*]}"
 readonly pattern="${args[0]}"
 
@@ -249,6 +252,7 @@ for d in "${dirs[@]}"; do
 done
 # set dirs to Absolute Path
 $use_absolute_path && dirs=("${tmp_dirs[@]}")
+readonly dirs
 
 # convert extensions to find -iname options
 find_iname_options=()
@@ -257,6 +261,7 @@ for e in "${extensions[@]}"; do
         find_iname_options=(-iname "*.$e") ||
         find_iname_options=("${find_iname_options[@]}" -o -iname "*.$e")
 done
+readonly find_iname_options
 
 ################################################################################
 # Check the existence of command for listing zip entry!
@@ -291,6 +296,8 @@ __prepareCommandToListZipEntries() {
     else
         die "NOT found command to list zip entries: zipinfo, unzip or jar!"
     fi
+
+    readonly command_to_list_zip_entries is_use_zip_cmd_to_list_zip_entries
 }
 __prepareCommandToListZipEntries
 
diff --git a/bin/rp b/bin/rp
@@ -14,6 +14,7 @@ set -eEuo pipefail
 
 # NOTE: DO NOT declare var PROG as readonly, because its value is supplied by subshell.
 PROG="$(basename "$0")"
+readonly PROG
 readonly PROG_VERSION='2.5.0-dev'
 
 ################################################################################
@@ -112,6 +113,7 @@ else
 fi
 
 [ -f "$relativeTo" ] && relativeTo="$(dirname "$relativeTo")"
+readonly files relativeTo
 
 for f in "${files[@]}"; do
     ! [ -e "$f" ] && {
diff --git a/bin/show-busy-java-threads b/bin/show-busy-java-threads
@@ -21,6 +21,7 @@
 
 # NOTE: DO NOT declare var PROG as readonly, because its value is supplied by subshell.
 PROG="$(basename "$0")"
+readonly PROG
 readonly PROG_VERSION='2.5.0-dev'
 # choosing between $0 and BASH_SOURCE
 # https://stackoverflow.com/a/35006505/922688
@@ -35,6 +36,7 @@ readonly -a COMMAND_LINE=("${BASH_SOURCE[0]}" "$@")
 #
 # NOTE: DO NOT declare var USER as readonly, because its value is supplied by subshell.
 USER="$(whoami)"
+readonly USER
 
 ################################################################################
 # util functions
@@ -219,6 +221,7 @@ ARGS=$(
     echo
     usage 1
 }
+readonly ARGS
 eval set -- "${ARGS}"
 
 count=5
@@ -265,7 +268,7 @@ while true; do
         shift
         ;;
     -l | --lock-info)
-        more_lock_info=-l
+        lock_info=-l
         shift
         ;;
     -h | --help)
@@ -281,16 +284,19 @@ while true; do
     esac
 done
 
-update_delay=${1:-0}
+readonly count cpu_sample_interval force mix_native_frames lock_info
+readonly update_delay=${1:-0}
 isNonNegativeFloatNumber "$update_delay" || die "update delay($update_delay) is not a non-negative float number!"
 
 [ -z "$1" ] && update_count=1 || update_count=${2:-0}
 isNaturalNumber "$update_count" || die "update count($update_count) is not a natural number!"
+readonly update_count
 
 if [ -n "$pid_list" ]; then
     pid_list="${pid_list//[[:space:]]/}" # delete white space
     isNaturalNumberList "$pid_list" || die "pid(s)($pid_list) is illegal! example: 42 or 42,99,67"
 fi
+readonly pid_list
 
 # check the directory of append-file(-a) mode, create if not exist.
 if [ -n "$append_file" ]; then
@@ -307,6 +313,7 @@ if [ -n "$append_file" ]; then
         fi
     fi
 fi
+readonly append_file
 
 # check store directory(-S) mode, create directory if not exist.
 if [ -n "$store_dir" ]; then
@@ -317,6 +324,7 @@ if [ -n "$store_dir" ]; then
         mkdir -p "$store_dir" || die "fail to create directory $store_dir(specified by option -S, for storing output files)!"
     fi
 fi
+readonly store_dir
 
 isNonNegativeFloatNumber "$cpu_sample_interval" || die "cpu sample interval($cpu_sample_interval) is not a non-negative float number!"
 
@@ -349,13 +357,15 @@ elif command -v jstack &>/dev/null; then
 else
     die "jstack NOT found by JAVA_HOME(${JAVA_HOME:-not set}) setting and PATH!${nl}Use -s option set jstack path manually."
 fi
+readonly jstack_path
 
 ################################################################################
 # biz logic
 ################################################################################
 
 # NOTE: DO NOT declare var run_timestamp as readonly, because its value is supplied by subshell.
 run_timestamp="$(date "+%Y-%m-%d_%H:%M:%S.%N")"
+readonly run_timestamp
 readonly uuid="${PROG}_${run_timestamp}_${$}_${RANDOM}"
 
 readonly tmp_store_dir="/tmp/${uuid}"
@@ -520,7 +530,7 @@ printStackOfThreads() {
         local jstackFile="${store_file_prefix}$((update_round_num + 1))_jstack_${pid}"
         [ -f "${jstackFile}" ] || {
             # shellcheck disable=SC2206
-            local -a jstack_cmd_line=("$jstack_path" ${force} $mix_native_frames $more_lock_info ${pid})
+            local -a jstack_cmd_line=("$jstack_path" ${force} $mix_native_frames $lock_info ${pid})
             if [ "${user}" == "${USER}" ]; then
                 # run without sudo, when java process user is current user
                 logAndRun "${jstack_cmd_line[@]}" >"${jstackFile}"
diff --git a/bin/tcp-connection-state-counter b/bin/tcp-connection-state-counter
@@ -12,6 +12,7 @@ set -eEuo pipefail
 
 # NOTE: DO NOT declare var PROG as readonly, because its value is supplied by subshell.
 PROG="$(basename "$0")"
+readonly PROG
 readonly PROG_VERSION='2.5.0-dev'
 
 ################################################################################
diff --git a/bin/uq b/bin/uq
@@ -24,6 +24,7 @@ set -eEuo pipefail
 
 # NOTE: DO NOT declare var PROG as readonly, because its value is supplied by subshell.
 PROG="$(basename "$0")"
+readonly PROG
 readonly PROG_VERSION='2.5.0-dev'
 
 ################################################################################
diff --git a/bin/xpl b/bin/xpl
@@ -21,6 +21,7 @@ set -eEuo pipefail
 
 # NOTE: DO NOT declare var PROG as readonly, because its value is supplied by subshell.
 PROG="$(basename "$0")"
+readonly PROG
 readonly PROG_VERSION='2.5.0-dev'
 
 readonly nl=$'\n' # new line
@@ -61,6 +62,7 @@ progVersion() {
 ################################################################################
 
 declare -a args=()
+selected=false
 while [ $# -gt 0 ]; do
     case "$1" in
     -s | --selected)
@@ -88,28 +90,30 @@ while [ $# -gt 0 ]; do
     esac
 done
 
+readonly args selected
+
 ################################################################################
 # biz options
 ################################################################################
 
 # open one file
 openOneFile() {
-    local file="$1"
+    local file="$1" slt="${selected}"
 
     case "$(uname)" in
     Darwin*)
-        [ -f "${file}" ] && selected=true
-        open ${selected:+-R} "$file"
+        [ -f "${file}" ] && slt=true
+        open ${slt:+-R} "$file"
         ;;
     CYGWIN*)
-        [ -f "${file}" ] && selected=true
-        explorer ${selected:+/select,} "$(cygpath -w "${file}")"
+        [ -f "${file}" ] && slt=true
+        explorer ${slt:+/select,} "$(cygpath -w "${file}")"
         ;;
     *)
         if [ -d "${file}" ]; then
             nautilus "$(dirname "${file}")"
         else
-            if [ -z "${selected}" ]; then
+            if [ -z "${slt}" ]; then
                 nautilus "$(dirname "${file}")"
             else
                 nautilus "${file}"
