Selecting lines which match any word from a list with grep

Can grep pick lines if at least one element from a list of words appeared? For example

grep "hello开发者_如何学Go world" file1 

grep must give me all lines which have either the word hello or the word world or both of them.

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grep "hello\|world" file1

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put your patterns in some file patterns.txt, one pattern per line, and run

grep -Ff patterns.txt file1

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How about

grep -r "hello\|world" file1

That's a recursive grep by the way. It searches recursively for the term "hello world" in file1. It can also apply to a directory like so:

grep -r "hello\|world" dir/dir2/

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Try this,

echo "hello world "| grep -o  "\bworld\b" 

output is

world 

or

grep -E 'hello|world' filename