如何抓取过滤结果的数量

Question

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I use grep -E '^[ 0-9]{6}$' to grab strings of 5 digits (numbers or space) in files

It returns:

71 051
17 293
017299
862610

But is it possible to extract only the 2 first occurrences? If possible like this in this example "71051-17293"?

Answer 1

Two options to grep only two lines max:

$ grep -Em2 '^[ 0-9]{6}$'
71 051
17 293
$ grep -E '^[ 0-9]{6}$' | head -n2
71 051
17 293