Problems with PRINTF...

[Mike Button]

Hey All,

I have a text document that has 7 columns. The document is a result of echo'ing a group of variables. The document has up to 100 lines, but when I view the data it is not aligned great. It is all jagged and over the place, making it hard to view. Someone has told me that I can use PRINTF to specify column widths and tab delimeters to clean things up, but after revewing the man pages on PRINTF I am lost. Is there anyone that can help me??

Thanks,
Mike Button

P.S. The columns are like this.
1 -> string
2 - 7 -> numeric (1 -5 max per column)

[John Poff · Accepted solution]

Hi Mike,

One way to do it is with awk. With printf, you specify the type of field and the length of the field. For strings, you use the %s parameter. For numbers, you have several choices, but you'll probably want the %d parameter for decimal integers. Something like this might work:

awk '{printf("%20s %6d %6d %6d %6d %6d %6d\n", $1, $2, $3, $4, $5, $6, $7)}' myfile

The \n adds a new line. You can also use \t to insert tab characters, but specifying the field lengths usually makes things print pretty cleanly without any tabs.

I know you can use printf in shell scripts but I haven't played with it. The printf in awk is pretty much like the one in C and Perl, and it gets the job done for me.

JP

[Mike Button]

Thanks for the suggestion, but after trying it, why I get is one line from my document and then one line that looks like this, 20s %6d %6d %6d %6d %6d %6d

Any suggestion, here is my command:

awk '{print ("20s %6d %6d %6d %6d %6d %6d\n", $1, $2, $3, $4, $5, $6, $7)}' myfile >myfile2

[John Poff]

Hi,

You typed 'print' instead of 'printf', and your first parameter should be %20s instead of just 20s. Try it that way and see what you get.

JP

[Mike Button]

Ever have one of those days...Thanks a lot...Things look great.

Mike

[susan gregory_1]

Hi Mike,
You don't have to do that in awk, you can do the same thing in your C program.

printf("%20s%7d\n", mystring, myint);

will put the string right justified starting at the 20th column and the integer at right justified at the 17th column.