bash實作兩個檔案的并交減集合操作：
A U B = cat a.txt b.txt | sort | uniq
A ^ B = cat a.txt b.txt | sort | uniq -d
A - B = cat a.txt b.txt b.txt | sort | uniq–u
bash實作兩個檔案的并交減集合操作：
A U B = cat a.txt b.txt | sort | uniq
A ^ B = cat a.txt b.txt | sort | uniq -d
A - B = cat a.txt b.txt b.txt | sort | uniq–u
![linux-svn解除安裝與安裝[圖]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)