Use awk to print first column, second column and one column every four after that

问题

I have a text file and I want to extract the first column, second column and one column every 3 after that. Also, I want to get rid of row #2. How can I do that using awk or similar?

An example: I have a text file as such:

A B C D E F G H I J .. N (header 1)
A B C D E F G H I J .. N (header 2)
A B C D E F G H I J .. N (row 1)
A B C D E F G H I J .. N (row 2)
A B C D E F G H I J .. N (row n)

I'm trying to get it as

A B F J .. N (header 1)
A B F J .. N (row 1)
A B F J .. N (row 2)
A B F J .. N (row n)

Thanks.

P.s. I've tried playing with the solutions mentioned in How to print every 4th column up to nth column and from (n+1)th column to last using awk? but the solution doesn't work for me

回答1:

$ awk 'NR!=2{out=$1; for (i=2;i<=NF;i+=4) out = out OFS $i; print out}' file
A B F J 1)
A B F J 1)
A B F J 2)
A B F J n)

The above output is messy because of the ...s and comments in your sample input that make it untestable. Always post ACTUAL, testable input/output, not a description or other abstract representation of such. And don't repeat the same data on every line as that makes it hard to map the output fields to the input and so makes it harder to understand your requirements. This would have been a more useful example:

$ cat file
101 102 103 104 105 106 107 108 109 110 111
201 202 203 204 205 206 207 208 209 210 211
301 302 303 304 305 306 307 308 309 310 311
401 402 403 404 405 406 407 408 409 410 411

$ awk 'NR!=2{out=$1; for (i=2;i<=NF;i+=4) out = out OFS $i; print out}' file
101 102 106 110
301 302 306 310
401 402 406 410

来源：https://stackoverflow.com/questions/31950514/use-awk-to-print-first-column-second-column-and-one-column-every-four-after-tha