shell学习笔记之实际应用一

此脚本是将指定输入格式转换为8字节对齐的文本，供大家参考学习shell

#!/bin/bash
#Extract text in a fixed format, Mainly for input board output

rm -rf $2	#remove file
left="{"
count=1
is_count=0
while read line		#read file
do
		length=${line:12:6} #get substring
		if [ "$length" == "length" ]
		then
				is_count=1
		fi
		if [ $is_count == 1 ]
		then
				let count++
				if [ $count == 4 ]
				then
						count=1
						is_count=0
				fi
				continue
		fi
		head=${line:24:1}
		del_spa=
		if [ "$head" == "$left" ]
		then
				del_spa=$(echo ${line:25:12}${line:40:12}${line:53} | tr -d '[ \t]')
				echo ${del_spa:0:16} >> $2
				echo ${del_spa:16} >> $2
		else
				del_spa=$(echo ${line:24} | tr -d '[ \t]')
				echo ${del_spa:0:16} >> $2
				echo ${del_spa:16} >> $2
		fi
done < $1