使用grep查找一行中的特定模式

Question

I am trying to find a specific pattern in a text file using grep inside a bourne shell script

The style is: word1 word2 word3

I want to print everything that is not of that style. So far I used

grep -e '[[:space:]]\{2,\}' somefile

to find more than 2 empty spaces between the words, but I cannot figure out how to make it so that the 3 word per line limit is retained.

My other method would be to also count how many words there are per line and if it exceeds 3, to print the line. Or to check for a white space at the end of the 3rd word, but I am unsure how that would be formatted.

Answer 1

I'm not sure if that's what you wanted, but here:

 ]$ cat input one one two one two three one two three four ]$ grep -v -e "^[^[:space:]]\\+ [^[:space:]]\\+ [^[:space:]]\\+$" input one one two one two three four 

We match:

• any number of not spaces: [^[:space:]]\\+
• until we get a space
• repeated 3 times
• all this should be in one line: ^...$
• and we negate this with -v option