Awk: compare version strings

bgstack15 — Wed, 28 Oct 2020 12:43:44 GMT

When I was working on my dpkg for notepad++, I discovered that the naming convention changed for the release assets. So starting with version 7.9, the filenames include ".portable" instead of ".bin." I don't care about the change, but I need my automatic downloader to handle it. So, I had to add some logic for checking if the requested version number is greater than or equal to 7.9. But there is another layer of sub- version to deal with, because I know the previous release was 7.8.9. So I whipped up some awk to help me.

echo "7.8.9" | awk -v 'maxsections=3' -F'.' 'NF < maxsections {printf("%s",$0);for(i=NF;i<maxsections;i++)printf("%s",".0");printf("\n")} NF >= maxsections {print}' | awk -v 'maxdigits=2' -F'.' '{print $1*10^(maxdigits*2)+$2*10^(maxdigits)+$3}'

The output will look like:

Which can then just be compared as a number with 70900 and then I can use the new naming convention. The tunables in this snippet include the awk variables: maxsections, and maxdigits. If the input version strings were to contain large numbers, such as "7.20.5" or "6028.423.2143" then you can increase the maxdigits. I realize that the second awk statement only handles a hard-coded amount of 3 sections. I need to figure out how to improve it so it can dynamically handle the number of sections defined in "maxsections" and handle the output when the maxsections is lower than the amount of fields being printed.

Compare two files in hexadecimal view

bgstack15 — Fri, 13 Sep 2019 12:40:51 GMT

Just a quick and dirty list for myself. When I was looking for hexeditors with a file-compare view, these came up. All three of these options seem useful in slightly different ways. vbindiff dhex vimdiff and :%!xxd Vimdiff just calls vim with a bunch of preset options.

vimdiff file1 file2

Once inside, you have to convert each file with :%!xxd and then after making any changes, convert back with :%!xxd -r before saving. Slightly clunky, and I'm sure there's a way to automate all that. But I was only making select changes. And a few keystrokes isn't so bad.

Knowledge Base (Posts about compare)

Awk: compare version strings

Compare two files in hexadecimal view