shell 初始化二进制文件

项目中需要创建一个二进制文件，文件大小为512kb，文件的每一个字节初始化为0xff，没找到比较方便的工具，就l写了个shell脚本，顺便熟悉下shell编程。

#!/bin/bash

# author: lizhi <ddgooo@hotmail.com>
# date: 2012-09-25-11:33
# file: create-my-file.sh
# description: create binary file and init dada and size;
# eg. size:1KB name:test file created by command:
# ./create-my-file.sh test -byte ff 1024
# every byte value 0xFF

if [ $# -ne 4 ];then
echo "Use format: $0 filename datatype[-string -decimal -octal -hex -bit -byte] initdata initcount"
echo "datatype: define the \"initdata\" data \type,used:"
echo " -string fill file with any bytes string data "
echo " -decimal fill file with 4 bytes decimal number "
echo " -octal fill file with 4 bytes octal number"
echo " -hex fill file with 4 bytes byte data,eg. ffffffff "
echo " -bit fill file with 1 byte data,eg. 11101101 "
echo " -byte fill file with 1 byte data,eg. ff "
echo "initdata: set the init data,fill file with this dada"
echo "initcount: filled count"
exit 1
fi

filename=$1
datatype=$2
initdata=$3
initcount=$4

echo "filename=$filename datatype=$datatype initdata=$initdata initcount=$initcount"

# string data type
if [ "$datatype" == "-string" ]; then
datalen='expr length $initdata'
echo "data length $datalen"
counter=0
while [ "$counter" -lt "$initcount" ]
do
echo -n $initdata >> $filename
((counter++))
echo "counter=$counter initdata=$initdata"
done
exit 0
fi

# other data type

hexdata=$initdata
if [ "$datatype" == "-decimal" ]; then
hexdata=`echo "ibase=10; obase=16; $initdata" | bc`
elif [ "$datatype" == "-octal" ]; then
hexdata=`echo "ibase=8; obase=16; $initdata" | bc`
elif [ "$datatype" == "-bit" ]; then
hexdata=`echo "ibase=2; obase=16; $initdata" | bc`
elif [ "$datatype" != "-byte" ] && [ "$datatype" != "-hex" ]; then
echo "datatype error"
exit 1
fi
echo "hexdata=$hexdata"

# format data as FFFFFFFF
format_hexdata=`printf "%08x" 0x$hexdata`
echo "format_hexdata=$format_hexdata"
# sed parttern
if [ "$datatype" == "-bit" ] || [ "$datatype" == "-byte" ]; then
sed_partten="`echo $format_hexdata | sed 's/[0-9a-zA-Z]\{2\}/& /g' | awk '{print "\\\\x"$4}'`"
else
sed_partten="`echo $format_hexdata | sed 's/[0-9a-zA-Z]\{2\}/& /g' | awk '{print "\\\\x"$4 "\\\\x"$3 "\\\\x"$2 "\\\\x"$1}'`"
fi
echo "sed_partten=$sed_partten"

# write file,begin 0pos write 1byte
counter=0
while [ $counter -lt $initcount ]
do
echo -e -n "$sed_partten" >> $filename # -n: No Newline; -e: enable interpretation of backslash escapes
((counter++))
done

 echo "successed"

exit 0