【Shell】脚本代码改写pipes.sh易读版本

悠悠 2024-04-03 09:45 24阅读 0赞

源脚本不太利于学生学习，故整改大部分代码，便于学生学习：

整改后脚本（31行）：

#!/bin/bash
    
    screen_width=$(tput cols) 
    screen_height=$(tput lines)
    path_array="┃┏ ┓┛━┓  ┗┃┛┗ ┏━"
    
    random_number=0 
    direction=0
    position_x=0
    position_y=0
    tput reset #重置终端属性为默认值
    tput civis #光标不可见
    while ! read -t0.01 -n1; 
    do
    	# New position:
    	#echo "direction: $direction, random_number: $random_number"
    	((${
        direction}%2)) && ((position_x+=-${
        direction}+2)) || ((position_y+=${
        direction}-1))
    
    	# Loop on edges (change color on loop):
    	((${
        position_x}>screen_width||${
        position_x}<0||${
        position_y}>screen_height||${
        position_y}<0))
    	((position_x=(position_x+screen_width)%screen_width))
    	((position_y=(position_y+screen_height)%screen_height))
    
    	# New random direction:
    	((random_number=RANDOM%13-1))
    	((random_number=(${
        random_number}>1||${
        random_number}==0) ? ${
        direction}:${
        direction}+${
        random_number}))
    	((random_number=(${
        random_number}<0)?3:${
        random_number}%4))
    
    	# Print:
    	tput cup ${
        position_y} ${
        position_x} #将光标移动到任意 X 或 Y 坐标
    	echo -ne "\033[1;31m"
    	echo -n "${path_array:direction*4+random_number:1}"
    	direction=${
        random_number}
    done

整改前脚本（78行）：

作者：林果皞
    链接：https://www.zhihu.com/question/30854445/answer/114873278
    来源：知乎
    著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。
    
    #!/bin/bash
    # The author of the original script is unknown to me. The first entry I can
    # find was posted at 2010-03-21 09:50:09 on Arch Linux Forums (doesn't mean the
    # poster is the author at all):
    #
    #   Post your handy self made command line utilities (Page 37) / Programming & Scripting / Arch Linux Forums
    #
    # I, Yu-Jie Lin, made a few changes and additions:
    #
    #   -p, -t, -R, and -C
    #
    #   Screenshot: http://flic.kr/p/dRnLVj
    #   Screencast: http://youtu.be/5XnGSFg_gTk
    #
    # And push the commits to Gist:
    #
    #   https://gist.github.com/4689307
    #
    # I, Devin Samarin, made a few changes and additions:
    #
    #   -r can be 0 to mean "no limit".
    #   Reset cursor visibility after done.
    #   Cleanup for those people who want to quit with ^C
    #
    #   Pushed the changes to https://gist.github.com/4725048
    #   hole1: https://gist.githubusercontent.com/livibetter/4689307/raw/949e43fe2962c2c97c8b1d974ff93dd053d9bd37/pipes.sh
    #   hole2: Fun On The Terminal Part 2
    
    p=1
    f=75 s=13 r=2000 t=0
    w=$(tput cols) h=$(tput lines)
    # ab -> idx = a*4 + b
    # 0: up, 1: right, 2: down, 3: left
    # 00 means going up   , then going up   -> ┃
    # 12 means going right, then going down -> ┓
    sets=(
        "┃┏ ┓┛━┓  ┗┃┛┗ ┏━"
        "│╭ ╮╯─╮  ╰│╯╰ ╭─"
        "│┌ ┐┘─┐  └│┘└ ┌─"
        "║╔ ╗╝═╗  ╚║╝╚ ╔═"
    )
    v="${sets[0]}"
    RNDSTART=0
    NOCOLOR=0
    
    OPTIND=1
    while getopts "p:t:f:s:r:RCh" arg; do
    case $arg in
        p) ((p=(OPTARG>0)?OPTARG:p));;
        t) ((OPTARG>=0 && OPTARG<${
        #sets[@]})) && v="${sets[OPTARG]}";;
        f) ((f=(OPTARG>19 && OPTARG<101)?OPTARG:f));;
        s) ((s=(OPTARG>4 && OPTARG<16 )?OPTARG:s));;
        r) ((r=(OPTARG>=0)?OPTARG:r));;
        R) RNDSTART=1;;
        C) NOCOLOR=1;;
        h) echo -e "Usage: $(basename $0) [OPTION]..."
            echo -e "Animated pipes terminal screensaver.\n"
            echo -e " -p [1-]\tnumber of pipes (D=1)."
            echo -e " -t [0-$((${
          #sets[@]} - 1))]\ttype of pipes (D=0)."
            echo -e " -f [20-100]\tframerate (D=75)."
            echo -e " -s [5-15]\tprobability of a straight fitting (D=13)."
            echo -e " -r LIMIT\treset after x characters, 0 if no limit (D=2000)."
            echo -e " -R \t\trandom starting point."
            echo -e " -C \t\tno color."
            echo -e " -h\t\thelp (this screen).\n"
            exit 0;;
        esac
    done
    
    cleanup() {
        
        tput rmcup
        tput cnorm
        exit 0
    }
    trap cleanup SIGHUP SIGINT SIGTERM
    
    for (( i=1; i<=p; i++ )); do
        c[i]=$((i%8)) n[i]=0 l[i]=0
        ((x[i]=RNDSTART==1?RANDOM*w/32768:w/2))
        ((y[i]=RNDSTART==1?RANDOM*h/32768:h/2))
    done
    
    tput smcup
    tput reset
    tput civis
    while ! read -t0.0$((1000/f)) -n1; do
        for (( i=1; i<=p; i++ )); do
            # New position:
            ((${
        l[i]}%2)) && ((x[i]+=-${
        l[i]}+2,1)) || ((y[i]+=${
        l[i]}-1))
    
            # Loop on edges (change color on loop):
            ((${
        x[i]}>w||${
        x[i]}<0||${
        y[i]}>h||${
        y[i]}<0)) && ((c[i]=RANDOM%8))
            ((x[i]=(x[i]+w)%w))
            ((y[i]=(y[i]+h)%h))
    
            # New random direction:
            ((n[i]=RANDOM%s-1))
            ((n[i]=(${
        n[i]}>1||${
        n[i]}==0)?${
        l[i]}:${
        l[i]}+${
        n[i]}))
            ((n[i]=(${
        n[i]}<0)?3:${
        n[i]}%4))
    
            # Print:
            tput cup ${
        y[i]} ${
        x[i]}
            [[ $NOCOLOR == 0 ]] && echo -ne "\033[1;3${c[i]}m"
            echo -n "${v:l[i]*4+n[i]:1}"
            l[i]=${
        n[i]}
        done
        ((r>0 && t*p>=r)) && tput reset && tput civis && t=0 || ((t++))
    done
    
    cleanup

https://www.zhihu.com/question/30854445  
运行效果：  
![在这里插入图片描述][4901cf376da74f40b3d9c63ed53d9118.png]

[4901cf376da74f40b3d9c63ed53d9118.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/03/24e039d2e79d44deb531438ad0c2c4a5.png