Count number of lines in a Fixed length file with a specific character in 12th Position in each line

Question

I have a Fixed length file, it is a large file with millions of records. The length of the record in each line is 19. In each line 12th character corresponds to a particular status for which I need to get the count of each status in the file. Eg:

XXXXXXXXXXX**1**XXXXXXXXX        
XXXXXXXXXXX**2**XXXXXXXXX      
XXXXXXXXXXX**3**XXXXXXXXX   
XXXXXXXXXXX**4**XXXXXXXXX

I need to do get the count of lines with 1 in 12th character of line, 2,3, and 4.

I'm using java as programming language.

@aleb2000: I tried this in terminal and find it to be working in terminal but I dont know how to do it from java. grep -c -e "^...........4" — normalindon1, Dec 05 '16 at 15:37
You say that the length of each line is 19 but your lines have a length of 21... — aleb2000, Dec 05 '16 at 16:19
If you're using java why did you tag it with awk? If you're happy with an awk solution why are you telling us you're using java? [edit] your question to clean that up and show a [mcve] including concise, testable sample input and expected output. — Ed Morton, Dec 06 '16 at 01:22

Anton Balaniuc · Answer 1 · 2016-12-05T16:20:40.953

0

You can try to use Files class:

Files.lines(path_to_fle).filter(s -> s.charAt(11) == '1').count();

But probably it will be more efficient if you will use grep for this?

edited Dec 05 '16 at 16:20

answered Dec 05 '16 at 15:40

Anton Balaniuc

10,889
1
35
53

More efficient? cut -c 12 file | sort | uniq -c But that doesn't get it done in java... – ivanivan Dec 05 '16 at 16:00
to get the 12th char you have to write `s.charAt(11)` since the count of the chars start at 0. – aleb2000 Dec 05 '16 at 16:17

aleb2000 · Accepted Answer · 2016-12-05T16:37:21.620

This is a bit longer than the one provided by @Anton.

public class Test {

    public static void main(String[] args) throws IOException {
        File file = new File("myfile.txt");
        String[] lines = Files.readAllLines(file.toPath()).toArray(new String[0]);
        lines = Arrays.stream(lines).map(l -> l.replaceAll("^.{11}(\\d).*$", "$1")).toArray(String[]::new);

        long n1 = Arrays.stream(lines).filter(s -> s.equals("1")).count();
        long n2 = Arrays.stream(lines).filter(s -> s.equals("2")).count();
        long n3 = Arrays.stream(lines).filter(s -> s.equals("3")).count();
        long n4 = Arrays.stream(lines).filter(s -> s.equals("4")).count();

        System.out.println("n1 = " + n1 + ", n2 = " + n2 + ", n3 = " + n3 + ", n4 = " + n4);
    }

}

Count number of lines in a Fixed length file with a specific character in 12th Position in each line

2 Answers2