show-busy-java-threads脚本内容及使用过程

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#!/bin/bash
# @Function
# Find out the highest cpu consumed threads of java processes, and print the stack of these threads.
#
# @Usage
#   $ ./show-busy-java-threads
#
# @online-doc https://github.com/oldratlee/useful-scripts/blob/master/docs/java.md#-show-busy-java-threads
# @author Jerry Lee (oldratlee at gmail dot com)
# @author superhj1987 (superhj1987 at 126 dot com)

readonly PROG="`basename $0`"
readonly -a COMMAND_LINE=("$0" "$@")
# Get current user name via whoami command
#   See https://www.lifewire.com/current-linux-user-whoami-command-3867579
# Because if run command by `sudo -u`, env var $USER is not rewritten/correct, just inherited from outside!
readonly USER="`whoami`"

################################################################################
# util functions
################################################################################

# NOTE: $'foo' is the escape sequence syntax of bash
readonly ec=$'\033' # escape char
readonly eend=$'\033[0m' # escape end

colorEcho() {
   
   
    local color=$1
    shift

    # if stdout is console, turn on color output.
    [ -t 1 ] && echo "$ec[1;${color}m$@$eend" || echo "$@"
}

colorPrint() {
   
   
    local color=$1
    shift

    colorEcho "$color" "$@"
    [ -n "$append_file" -a -w "$append_file" ] && echo "$@" >> "$append_file"
    [ -n "$store_dir" -a -w "$store_dir" ] && echo "$@" >> "${store_file_prefix}$PROG"
}

normalPrint() {
   
   
    echo "$@"
    [ -n "$append_file" -a -w "$append_file" ] && echo "$@" >> "$append_file"
    [ -n "$store_dir" -a -w "$store_dir" ] && echo "$@" >> "${store_file_prefix}$PROG"
}

redPrint() {
   
   
    colorPrint 31 "$@"
}

greenPrint() {
   
   
    colorPrint 32 "$@"
}

yellowPrint() {
   
   
    colorPrint 33 "$@"
}

bluePrint() {
   
   
    colorPrint 36 "$@"
}

die() {
   
   
    redPrint "Error: $@" 1>&2
    exit 1
}

logAndRun() {
   
   
    echo "$@"
    echo
    "$@"
}

logAndCat() {
   
   
    echo "$@"
    echo
    cat
}

usage() {
   
   
    local -r exit_code="$1"
    shift
    [ -n "$exit_code" -a "$exit_code" != 0 ] && local -r out=/dev/stderr || local -r out=/dev/stdout

    (( $# > 0 )) && { echo "$@"; echo; } > $out

    > $out cat <<EOF
Usage: ${PROG} [OPTION]... [delay [count]]
Find out the highest cpu consumed threads of java processes,
and print the stack of these threads.
Example:
  ${PROG}       # show busy java threads info
  ${PROG} 1     # update every 1 second, (stop by eg: CTRL+C)
  ${PROG} 3 10  # update every 3 seconds, update 10 times
Output control:
  -p, --pid <java pid>      find out the highest cpu consumed threads from
                            the specified java process.
                            default from all java process.
  -c, --count <num>         set the thread count to show, default is 5.
  -a, --append-file <file>  specifies the file to append output as log.
  -S, --store-dir <dir>     specifies the directory for storing
                            the intermediate files, and keep files.
                            default store intermediate files at tmp dir,
                            and auto remove after run. use this option to keep
                            files so as to review jstack/top/ps output later.
  delay                     the delay between updates in seconds.
  count                     the number of updates.
                            delay/count arguments imitates the style of
                            vmstat command.
jstack control:
  -s, --jstack-path <path>  specifies the path of jstack command.
  -F, --force               set jstack to force a thread dump. use when jstack
                            does not respond (process is hung).
  -m, --mix-native-frames   set jstack to print both java and native frames