picoCTF 2026 writeup-general skills-UNDO

I am backIve been delayed by the shcool work for so long!Today we will begin the picoctf 2026 writeup -- UNDO我回来了被学业耽搁太久了今天我们开始picoctf 2026的题解——UNDOFIRST,we connect the server and it show the hint:base64we all know,the base64 commnd is连接服务器我们得到了base64的提示我们都知道base64的命令是base64 -dCorrect!SECOND,the reverse command is逆转文本的命令是revjust theabbreviationofrev(erse)正是reverse的缩写Correct!THIRD,We need to replace the _ with -use tr command我们需要替换_ 用 -用 ‘tr’ 命令tr - _Correct!FOURTH,Now we should replace the {} with ()我们需要替换{} 用 ()tr () {}Correct!FIFTH,ROT13,just rotate the location of the alphabet to the next 13 lettera→n、b→o…m→zreversen→a、o→b…z→mA→N、B→O…M→ZreverseN→A、O→B…Z→MROT13,就是把字母表上的字母位置向后转13位tr a-zA-Z N-ZA-Mn-za-mnow we get the flag!现在我们得到了flagpicoCTF{Revers1ng_t3xt_Tr4nsf0rmt10ns_3a939318}