blink.sh

#!/usr/bin/bash

# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ #
#     脚本名称: blink.sh                                                       #
#     脚本用途: 打字机输出仿真                                                 #
#     开发作者: 木哥                                                           #
#     当前版本: 1.0                                                            #
#     更新日志:   <版本号>  |      <更新时间>     | <更新内容>                 #
#                   1.0     | 2023-06-05 23:00:00 | 脚本初始化                 #
# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ #

SCALES=2000
DELAY_SLEEP=200  # 光标闪烁的时间间隔
DELAY_START=1000 # 输入前等待时间
DELAY_END=2000   # 输入完毕后等待时间

# 打字间隔最高时间随机取值
DELAY_TYPES=(2 2 3 3 5 5 5 8 8 8 8 10 10 10 10 10 10 20 20 20)

# 控制并发命名管道
lock_fifo="/tmp/blink_$$.lock.fifo"
mkdir -p $(dirname "$lock_fifo")
mkfifo $lock_fifo
exec 10<>$lock_fifo
echo >&10

# ------------------------------------------------------- #

sleep_interval() {
    sleep $(echo "$1/$SCALES" | bc -l)
}

interrupt() {
    clean
    exit 1
}

clean() {
    tput cnorm # 恢复光标
    exec &>>/dev/null
    kill $pid_cursor
    kill $pid_type
    rm $lock_fifo
}

# ------------------------------------------------------- #

trap interrupt SIGINT SIGHUP

tput civis # 隐藏光标

# 光标闪烁进程
{
    while :; do
        # 光标闪烁 - 下划线
        sleep_interval $DELAY_SLEEP
        read -u 10
        {
            if [ "$s" = "e" ]; then
                break
            fi
            echo -n "█"
            echo 1 >&10
        }

        # 光标闪烁 - 空置
        sleep_interval $DELAY_SLEEP
        read -u 10 s
        {
            [ "$s" = 1 ] && echo -ne "\b"
            if [ "$s" = "e" ]; then
                break
            fi
            echo -ne " \b"
            echo 0 >&10
        }
    done
} 2>/dev/null &
pid_cursor=$!

# 稍作停顿
sleep_interval $DELAY_START

# 打字进程
{
    while IFS= read -r line; do
        # 空行
        if ((${#line} == 0)); then
            read -u 10
            {
                echo
                echo 2 >&10
            }
        fi

        # 遍历每个字符
        for ((i = 0; i < ${#line}; i++)); do
            cur_char=${line:$i:1}
            if [[ ! "$cur_char" =~ ^[[:space:]]*$ ]]; then
                delay_type_select=${DELAY_TYPES[ $((RANDOM % ${#DELAY_TYPES[@]})) ]}
                sleep_interval $((RANDOM % delay_type_select))
            fi
            read -u 10 s
            {
                [ "$s" = 1 ] && echo -ne "\b"
                echo -n "${line:$i:1}"
                # 如输出至一行中最后一个字符，直接输出"\n"
                ((i == ${#line} - 1)) && echo
                echo 2 >&10
            }
        done

    done

} 2>/dev/null
pid_type=$!

clean
exit 0