AWK学习总结（三） Records and Fields

AWK 记录和域

The NR Variable

% awk '{print NR, $0}'  employees

1 Tom Jones       4424      5/12/66     543354

2 Mary Adams      5346      11/4/63     28765

3 Sally Chang     1654      7/22/54     650000

4 Billy Black     1683      9/23/44     336500

NR 加入行号。逐行加一

$0 代表整行

NF 文件列数

% awk  '{print $0, NF}'  employees

Tom Jones        4444     5/12/66     543354     5

Mary Adams       5346      11/4/63     28765      5

Sally Chang      1654      7/22/54     650000     5

Billy Black      1683      9/23/44     336500     5

-F

% cat employees

Tom Jones:4424:5/12/66:543354

Mary Adams:5346:11/4/63:28765

Sally Chang:1654:7/22/54:650000

Billy Black:1683:9/23/44:336500

% awk –F: '/Tom Jones/{print $1, $2}'  employees2

Tom Jones  4424

eg2

% awk –F'[ :\t]'  '{print $1, $2, $3}' employees

Tom Jones 4424

Mary Adams 5346

Sally Chang 1654

Billy Black 1683

总结：学习了NR NF 变量  学会使用-F參数