shell 拆分字符串

如题： 打印前46个字符，后面按567个字符为一次交易 
文本文件如下：

000800048031000   2016121520161215PROD00000001300B80062122602000874285260000000003001561214230030296869ECC001    00000100003648031000   00031000   541177025509898110254114153TAIHE            000000000000000000000000000001871178801020000   01020000   003     1   00C000000000010  0000 000000016F4E7412ABAE096B072001601000C00000000000701FE33F0123456707010103900000010A010000004400307EC1DF                          00137C00161214156Y100000000000300156 250940000000000000      26A000000333010101                003000000000ECC001                                    0000000048031000    0000000048031000    0000000048031000    0000000048031000    00000000            00000000            00000000            00000000            00000000            00000000                                                                                                    D0000000232 00000000 00000000 00000000                                                                                                    300B80062122602000874285260000000003001561214230029297435ECC001    00000100048348031000   00031000   541177025511898110254114153TAIHE            000000000000000000000000000001871177801020000   01020000   003     1   00C000000000010  0000 00000001F5BB5F8333526916072001601000C00000000000CDA9395D0123456707010103900000010A01000000410026DBE246                          00157C00161214156Y100000000000300156 250940000000000000      26A000000333010101                003000000000ECC001                                    0000000048031000    0000000048031000    0000000048031000    0000000048031000    00000000            00000000            00000000            00000000            00000000            00000000                                                                                                    D0000000232 00000000 00000000 00000000                                                                                                    300B80062122602000874285260000000003001561214230027296115ECC001    00000100003548031000   00031000   541177025509898110254114153TAIHE            000000000000000000000000000001871176601020000   01020000   003     1   00C000000000010  0000 000000013DE0F72F2CDC1F3C072001601000C00000000000594D2B5E0123456707010103900000010A0100000047005A9114F1                          00117C00161214156Y100000000000300156 250940000000000000      26A000000333010101                003000000000ECC001                                    0000000048031000    0000000048031000    0000000048031000    0000000048031000    00000000            00000000            00000000            00000000            00000000            00000000                                                                                                    D0000000232 00000000 00000000 00000000                                                                                                    300B80062122602000874285260000000003001561214230031296116ECC001    00000100048448031000   00031000   541177025511898110254114153TAIHE            000000000000000000000000000001871180601020000   01020000   003     1   00C000000000010  0000 00000001EA2BCC000C1DD14A072001601000C000000000002E0F242E0123456707010103900000010A010000003800187FFCA3                          00177C00161214156Y100000000000300156 250940000000000000      26A000000333010101                003000000000ECC001                                    0000000048031000    0000000048031000    0000000048031000    0000000048031000    00000000            00000000            00000000            00000000            00000000            00000000                                                                                                    D0000000232 00000000 00000000 00000000                                                                                                    0018000000000000600000000000000000000000000000000

脚本如下：

#!/bin/env bash

export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin

mydate=$(date +'%y%m%d'）
FILE=/user/INF${mydate}51B
LINE=`cat $FILE`
echo ${LINE:0:46}
echo ${LINE:46:-1} > userline
/usr/bin/awk -F '?' '{line="";for(i=0;i<=length($0);i++){line=substr($0,i,i+567);i=i+567; print line}}' userline
rm -rf userline