sh 解码条形码文件，提取有用的base64信息并解码base64

Posted 2021-05-07

#!/bin/bash 

# decode a barcode file, extract useful base64 information and decode the base64
# Usage: decodebar64.sh /path/to/bar_img_file
#        ln -s /path/to/decodebar64.sh $HOME/bin/decodebar64.sh

BASE_DIR="$HOME/data/scripts/base64"
DECODE_STR_FILE="$BASE_DIR/decodebase64.py"

if [ "$#" -lt 1 ]
    then
        echo "Lack specific arg ..." 
        echo "Usage: $0 /path/to/bar_img_file"
        exit 0
fi

if [ ! -f "$1" ]; then
    echo "File $1 does not exist, exit."
    exit 0
fi

codestr=$(zbarimg "$1")

echo "codestr: $codestr "
if [ -z "$codestr" ]; then
    echo "Empty decoded content, exit."  
    exit 0
fi 

strlength=${#codestr}
echo "strlength: $strlength"

endindex=$(($strlength-13))
#echo "endindex: $endindex"

b64str=${codestr:13}
echo "b64str: $b64str"
    
decodedstr=$("$DECODE_STR_FILE" "$b64str")
#decodedstr=$(./decodebase64.py "$b64str")
if [ -z "$decodedstr" ]; then
    echo "Couldn't decode, exit."
    exit 0
fi
        
echo "Decodedstr: $decodedstr"