Understand sort and uniq commands (including uniq's-u and-d options)

Understand sort and uniq commands (including uniq's-u and-d options) [plain] catab | sort | uniq & gt; c # cisaunionb union set catab | sort | uniq-d & gt; c # cisaintersectb intersection cat... understand sort and uniq commands (including uniq's-u and-d options) [plain] cat a B | sort | uniq> c # c is a union B union cat a B | sort | uniq-d> c # c is a intersect B intersection cat a B B | sort | uniq-u> c # c is set difference a-B difference set view the content of file a B [root @ hadoop luanshous#] # cat a B LUAN SHOU SHEN 1111 2222 3333 luan kevin 1234 1111 use-c cat a B | sort | uniq-c 2 1111 1 1234 1 2222 1 3333 1 KEVIN 3 LUAN 2 SHEN 2 SHOU cat a B | sort | uniq // Union 1111 1234 2222 3333 kevin luan shen shou cat a B | sort | uniq-d // intersection 1111 luan shen shou cat a B | sort | uniq-u // difference set 1234 2222 3333 KEVIN