一個shell寫的urldecode代碼

轉自：http://aaronw.me/static/779.html

這是第一種方法：(標點符號會漏掉)

#!/bin/shawk ‘BEGIN {hextab=”0123456789ABCDEF”for ( i=1; i<=255; ++i ) ord [i] = sprintf(“%c”,i);}{decoded = “”for ( i=1; i<=length ($0); ++i ) {c = substr ($0, i, 1)if ( c ~ /[a-zA-Z0-9.-]/ ) {decoded = decoded c             # safe character} else if ( c == ” ” ) {decoded = decoded “+”   # special handling} else if ( c == “%” ) {hi= substr($0,i+1,1);low=substr($0,i+2,1);i++;i++decoded = decoded ord[(index(hextab,hi)-1)*16+index(hextab,low)-1]}}}END {print decoded}‘

這是第二種方法：

#/bin/shawk ‘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);}print i;}’