UNIX for Dummies Questions & Answers

Hi,

I have a space delimited text file with multiple columns 102 columns. I want to break it up into 100 files labelled 1.txt through 100.txt (n.txt). Each text file will contain the first two columns and in addition the nth column (that corresponds to n.txt). The third file will contain the first three columns and the fourth file will contain columns 1,2 and 4 and so on. How do I go about doing that? Thanks!

Assuming your system will allow 100 concurrent file descriptors to be open at the same time:

Code:

awk '
    {
        for( i = 3; i <= NF; i++ )
            printf( "%s %s %s\n", $1, $2, $(i) ) >i ".txt";
    }
' input-file

Should work.


Per your description 3.txt will contain columns 1,2 and 3; 4.txt will contain 1,2 and 4. There will not be 1.txt nor 2.txt as you indicated you want n.txt where n is the column in addition to 1 and 2. I hope I interpreted that correctly.

---------- Post updated at 22:42 ---------- Previous update was at 22:39 ----------

If your system will not allow 100 concurrently open FDs, then the code below should work -- not as efficient, and you will need to delete all text files if you need to rerun the programme.

Code:

awk '
    {
        for( i = 3; i <= NF; i++ )
        {
            fn = i ".txt";
            printf( "%s %s %s\n", $1, $2, $(i) ) >>fn;
            close( fn );
        }
    }
' input-file