问题
I would like to cut two columns from one file and stick them on the end of a second file. The two file have the exact same number of lines
file1.txt
1 2 3 4 5 6 7 8 9 10
1 2 3 4 5 6 7 8 9 10
1 2 3 4 5 6 7 8 9 10
file2.txt
a b c d e f g h i j
a b c d e f g h i j
a b c d e f g h i j
a b c d e f g h i j
So far I have been using
cut -f9-10 file2.txt | paste file1.txt - > file3.txt
which outputs exactly what I want
1 2 3 4 5 6 7 8 9 10 i j
1 2 3 4 5 6 7 8 9 10 i j
1 2 3 4 5 6 7 8 9 10 i j
However I don't want to have to make a new file I would prefer to alter file 1 to the above. I've tried
cut -f9-10 file2.txt | paste file1.txt -
but it simply prints everything on screen. Is there a way of just adding columns 9 and 10 to the end of file1.txt?
回答1:
Use sponge from moreutils! It allows you to soak up standard input and write to a file. That is, to replace a file in-place after a pipe.
cut -f9-10 file2.txt | paste file1.txt - | sponge file1.txt
Note you can also do what you are doing by using paste with a process substitution.
$ paste -d' ' file1.txt <(awk '{print $(NF-1), $NF}' file2.txt) | sponge file1.txt
$ cat file1.txt
1 2 3 4 5 6 7 8 9 10 i j
1 2 3 4 5 6 7 8 9 10 i j
1 2 3 4 5 6 7 8 9 10 i j
This joins file1.txt with two last columns from file2.txt using ' ' as delimiter.
来源：https://stackoverflow.com/questions/30927999/bash-cut-columns-to-one-file-and-save-onto-the-end-of-another-file