#!/bin/bash


[ -z $1 ]  echo "Input is invalid! "  exit 1

txt=($(cat $1|sed 's/ \+/_/g'))

lines=${#txt[@]}

max_show=10   #最多显示行数（超过总行数则设为总行数）

[ ${max_show} -gt ${lines} ]  max_show=${lines}

hlt_line=3  #高亮显示位置（不超过总行1/2，设为3实际是第4行）

[ ${hlt_line} -gt $(( lines / 2 )) ]  hlt_line=$(( lines / 2 ))

sTTY=$(stty -g)  #保存终端设置


clear

echo -ne "\033[?25l" #隐藏光标


spaces() {

local i j n

i=0; n=0

for (( j=0; j = ${lines}; j++ ));do

[ $i -lt ${#txt[$j]} ]  (( i = ${#txt[$j]} ))  (( n = $j ))

done

echo ${txt[$n]}|sed 's/./  /g'

}


space_line=$(spaces)


#传递的参数是欲显示行的序数：show 1 表示第一行高亮显示

show() {

local i j text crt_line

j=$1


for (( i=0; i  max_show; i++ ));do

crt_line=$(( j + i - hlt_line ))

if [ $i -eq ${hlt_line} ]  [ ${crt_line} -ge 0 ]  [ ${crt_line} -le ${lines} ];then

text="\033[;32m"${txt[${crt_line}]}"\033[0m"

elif [ ${crt_line} -lt 0 ] || [ ${crt_line} -gt ${lines} ];then

text=${space_line}

else

text=${txt[${crt_line}]}

fi

echo -ne "\033[$((i+3));0H${space_line}"

echo -ne "\033[$((i+3));6H${text}"

done

}


#测试

for (( j = 0; j  lines + hlt_line +1 ; j++ ));do

show $j

sleep 1

done

echo ""

stty ${sTTY} #恢复终端设置

echo -e "\033[?25h\033[0;0H" #恢复光标