文件名：url_decode.sh
#/bin/sh
awk'BEGIN{
for(i=0;i<10;i++)
hex[i]=i;
hex["A"]=hex["a"]=10;
hex["B"]=hex["b"]=11;
hex["C"]=hex["c"]=12;
hex["D"]=hex["d"]=13;
hex["E"]=hex["e"]=14;
hex["F"]=hex["f"]=15;
}
{
gsub(/\+/,"");
i=$0;
while(match(i,/%../)){
if(RSTART>1);
printf"%s",substr(i,1,RSTART-1);
printf"%c",hex[substr(i,RSTART+1,1)]*16+hex[substr(i,RSTART+2,1)];
i=substr(i,RSTART+RLENGTH);
}
printi;
}'

echo $url | ./url_decode.sh