How to zero-pad a char-formatted number that is greater than 16 digits?

[Cat_Dreamer]

I am trying to left-zero-pad an existing list of character-formatted numbers. The numbers vary from 6 digits to 20 digits. I want to zero-pad them to a length of 25.

The problem that I am having is that every method I can find to zero-pad involves using input() to change the character-formatted numbers to a number format. Because some of my numbers are greater than 16 digits, I am losing precision when I do that. It rounds up any numbers past the sas-recognized 16 limit. 

Is there any way to concatenate 0's to the left of a character-formatted field (up to 25 chars) while keeping it a character-formatted field??

[Kurt_Bremser]

outvar = "0000000000000000000000000";
invar = left(invar); /* removes leading blanks */
substr(outvar,26-length(invar)) = invar;

[heather_g]

I don't have time at the moment to write out all the SAS code, but yes, there are ways.

One way, in a data step - 

use the LENGTH() function to determine the original length of the character variable, then subtract that length from your total expected digits (fiddle with this, you probably have to add 1 in there). Then use the REPEAT() function to repeat zeroes to that number, and concatenate those zeroes with the original variable to create a new variable using one of the CAT() functions (forget if it's CATS or CATT or CATX). All of those functions can be found explained in the internet documentation.

[ballardw]

This link has several methods for a shorter string and a "less than" length requirement.

Should have somethings that are easy enough to make work with longer strings.

https://communities.sas.com/t5/SAS-Programming/convert-character-value-quot-1X11-quot-to-quot-000001...