paste命令
默认情况下分隔符为tab,可通过-d指定分隔符，-s则会让每个文件占用一行，见下面示例
合并文件 paste file1 file2
/mnt/d/code/vim_learn cat a.txt
kkfsaf
zhou_andy
/mnt/d/code/vim_learn cat b.txt
1
2
/mnt/d/code/vim_learn paste b.txt a.txt
1 kkfsaf
2 zhou_andy
/mnt/d/code/vim_learn paste -d : b.txt a.txt
1:kkfsaf
2:zhou_andy
/mnt/d/code/vim_learn cat a.txt
kkfsaf
zhou_andy
/mnt/d/code/vim_learn paste -s a.txt
kkfsaf zhou_andy
