如何从合并的文件中提取文件

Question

I want to separate a merged file into two files. The file:

file.dat

i =100
1 2 3
i =1
-1 -2 -3
i =101
1 2 3
i =102
1 2 3
i =103
1 2 3
i =2
-1 -2 -3 
....

The mixed indices are

1,2,3,4, ...,99 

and

100, 101, 102, 103,...,200.

The indices appear alternately, but there is no rule. The data

1 2 3 

and

-1 -2 -3 

just denote the data block in each step.

Could you give an idea to separate the merged file into two files with respect to the indices?

Answer 1

If you just want the data blocks appended to two different files, depending on which group of indexes it belongs to, this should work:

# separate.awk

{
  if ($1 == "i")
  {
    split($2,a,"=");
    i = a[2];
  }

  if (i < 100)
    print > "1-99.dat";
  else
    print > "100-200.dat"
}

---

$ awk -f separate.awk file.dat

$ cat 1-99.dat
i =1
-1 -2 -3
i =2
-1 -2 -3 

$ cat 100-200.dat
i =100
1 2 3
i =101
1 2 3
i =102
1 2 3
i =103
1 2 3

Answer 2

This awk should do it for you:

awk -F= '/=/{f="a.txt";if($2>99)f="b.txt";next} {print >f}' file.dat

First, it sets the field separator to = . Then it checks if the line contains an equals sign, and if so, it is time to set the name of the output file to either "a.txt" or "b.txt" depending on the number after the equals sign. Then on subsequent records we just write to the file we last selected.