Bashscripts.org

I've recently got back into a bit of shell scripting after starting a new job, and in an effort to speed up the build/configure process I have a script in the making. I have all of the OS/hardware verification automated with no user input necessary. However, in an effort to make this script user friendly for other employees I need a way to ensure the IP they submit is in the correct format under 255 and over 0 for the first octet.

I wrote the basis for it, but when the script runs it does not compare the values and ends up verifying the wrong information. I am not very experienced with shell scripting, and I am not even sure if using a function would work by forcing the user to re-input any invalid data or just continue down the rest of the code. I know there are plenty of better ways to complete this task, but it seemed that it was the easiest way to understand and complete for testing. I am completely open to suggestions, so I thank anyone that can help in any way possible.

Hi SteveC, welcome!

Here's a neat function that I found on another forum that looks pretty clean, using awk:




I hope this helps!
-J

the > character is used to redirect output from a command to a file (or device)
If you want a 'less than' or 'greater than' operator, lose the quotes and use -lt or -gt

Thanks, I'll try and mess with that because I am not too familiar with awk or |egrep and the format in the if statement that validates the numerical values. I'll take a look into some more guides so I can eventually filter different sets of user input. If you have any suggestions for tutorials I would greatly appreciate it.



I actually did use the -... operator at first, but when it didn't work I go rid of it and never tried it again when I revised the actual validation sequence. I knew that the > or >> could replace/send text to a file, but I guess my inexperience didn't think it would effect an if statement. Thanks a lot though that will help with lots of things.



As for anyone else that may happen to look at this thread; if you know of any good tutorials for more advanced coding (with explanations of what the given code does broken down) please leave a link on this post. I'm really sorry if there are guides on the forum I missed (I looked through the stickies for the most part), but I am very new and plan to stick around for a while to learn and hopefully one day help people with their issues.