How can I adjust the length of a column field in b

Question

I've an input.csv file in which columns 2 and 3 have variable lengtt.

100,Short Column, 199
200,Meeedium Column,1254
300,Loooooooooooong Column,35

I'm trying to use the following command to achieve a clean tabulation, but I need to fill the 2nd column with a certain number of blank spaces in order to get a fixed lenght column (let's say that a total lenght of 30 is enough).

awk -F, '{print $1 "\t" $2 "\t" $3;}' input.csv

My current output looks like this:

100   Short Column   199
200   Meeedium Column   1254
300   Loooooooooooong Column   35

And I would like to achieve the following output, by filling 2nd and 3rd column properly:

100   Short Column               199
200   Meeedium Column           1254
300   Loooooooooooong Column      35

Any good idea out there about awk or sed command should be used? Thanks everybody.

Answer 1

Use printf in awk

$ awk -F, '{gsub(/ /, "", $3); printf "%-5s %-25s%5s\n", $1, $2, $3}' file input.csv
100   Short Column               199
200   Meeedium Column           1254
300   Loooooooooooong Column      35

What I have done above, is set the IFS,field separator to ,; since the file has some white-spaces in the 3rd column alone, it mangles, how printf processes the strings, removing it with gsub and formatting in C-style printf.

Answer 2

Solution using perl

$ perl -pe 's/([^,]+),([^,]+),([^,]+)/sprintf "%-6s%-30s%5s", $1,$2,$3/e' input.csv
100   Short Column                   199
200   Meeedium Column               1254
300   Loooooooooooong Column          35

Answer 3

Rather than picking some arbitrary number as the width of each field, do a 2-pass approach where the first pass calculates the max length of each field and the 2nd prints the fields in a width that size plus a couple of spaces between fields:

$ cat tst.awk
BEGIN { FS=" *, *"; OFS="  " }
NR==FNR {
    for (i=1;i<=NF;i++) {
        w[i] = (length($i) > w[i] ? length($i) : w[i])
        if ($i ~ /[^0-9]/) {
            a[i] = "-"
        }
    }
    next
}
{
    for (i=1;i<=NF;i++) {
        printf "%"a[i]w[i]"s%s", $i, (i<NF ? OFS : ORS)
    }
}

$ awk -f tst.awk file file
100  Short Column             199
200  Meeedium Column         1254
300  Loooooooooooong Column    35

The above also uses left-alignment for non-digit fields, right alignment for all-digits fields. It'll work no matter how long the input fields are and no matter how many fields you have:

$ cat file1
100000,Short Column, 199,a
100,Now is the Winter of our discontent with fixed width fields,20000,b
100,Short Column, 199,c
200,Meeedium Column,1254,d
300,Loooooooooooong Column,35,e

$ awk -f tst.awk file1 file1
100000  Short Column                                                   199  a
   100  Now is the Winter of our discontent with fixed width fields  20000  b
   100  Short Column                                                   199  c
   200  Meeedium Column                                               1254  d
   300  Loooooooooooong Column                                          35  e