[SOLVED] BASH replace line

trintukaz · 10-09-2011, 01:19 AM

anyone?

David the H. · 10-09-2011, 01:20 AM

Again, test the contents of the variable first, in the shell, and only run the command if it has the value you want in it.

trintukaz · 10-09-2011, 01:39 AM

Can you write me an example. I almost finished work and I still can't solve this problem.

David the H. · 10-09-2011, 01:46 AM

:sigh:

It's a simple if test, one of the most basic parts of shell scripting.

http://mywiki.wooledge.org/BashGuide..._and_.5B.5B.29

Go back to the start and read through the whole guide too, while you're at it.

Now please stop asking us to do your work for you, and try to learn something. We've given you everything you need to figure out your problem...so figure it out.

If, after really trying, you still can't quite make it work, post the code you have and we'll help you improve it.

trintukaz · 10-09-2011, 02:02 AM

If I asked write contact book script for me that would be "asking us to do your work for you", but I am asking just show solution for only one situation. Or maybe you don't know answer? Then just tell.

grail · 10-09-2011, 02:40 AM

I can vouch for the fact that not only does David know the solution but could write it in several different ways.

However, he is trying to help you to learn not only how to solve this issue but also further ones. It seems quite obvious you want the solution
given to you and then when you hit the next problem you will also be back to have it solved for you as well.

As with most questions asked here, show us what you have tried and where you are stuck? You have been provided a number of links that
can help you solve this issue. I will provide yet another link:

http://tldp.org/LDP/abs/html/

This has more information on bash and the option to use an 'if' is included in its pages.

trintukaz · 10-09-2011, 02:51 AM

When you don't have a lot of time those links are useless.

lithos · 10-09-2011, 05:20 AM

try IF
like:

Code:

if ( [ "$fname" = "" ] )
then
... nothing...

elseif ( [ "$fname" != "" ] )
then 
... do the search/replace to the file

fi

and all the other fields ($sname $number $email) can be done like so.

grail · 10-09-2011, 05:42 AM

Quote:

When you don't have a lot of time those links are useless.

Hmmm ... now this sounds like homework that you have left to the last minute.

trintukaz · 10-09-2011, 06:00 AM

Nope. I hate when I don't finish job it is like headache ;D

trintukaz · 10-09-2011, 06:25 AM

Really please help i have been searching for solution half day. I need to make that $recnum should be for example 1-1000 else script do nothing because if I not enter any number it deletes all contacts.

theNbomr · 10-09-2011, 10:47 AM

Code:

if [ -z $recnum ]; then
   echo "Invalid null record number entry"
   exit 1
fi

You would have found this in the link already posted for you, but I'll narrow it down for this case:
http://tldp.org/LDP/abs/html/testconstructs.html

Telling someone that you don't have time to read the answer is a bit insulting. Those who do have the answers for you had to take the time to do the reading so they would have the answers. It isn't obvious how your time is more valuable than theirs, especially given that you are the one who gets all of the tangible benefit from getting the answer.

--- rod.

David the H. · 10-09-2011, 02:47 PM

I enjoy helping people with their scripts, really I do ... but only if they appear to be really interested in learning what I have to teach, and are willing to meet me half-way.

What I do not appreciate is being used as free tech support. If that's all you're interested in, then go pay someone to do the work. It's not my fault or my concern if you're low on time.

I'm sure I'm not alone in this attitude.

It really comes down to the way you present yourself. A person I would enjoy helping would say things like this:

I read the link, but I don't quite understand it. Here's what I tried. I think it should output "foo", but it's not working for me. Where am I going wrong? <posts example code>

Thanks for your help. This is what I came up with, and it seems to work. Are there any problems with it? <posts example code>

I see, so if you "foo" the "bar", then the "baz" will "bum", right? But what happens if you "bar" the "foo", like this? <posts example code>

This person shows interest in learning, and is participating in a two-way conversation. I would go out of my way to research things so we could both learn.

On the other hand, here's what a person I wouldn't want to help sounds like:

I can't find what I need
Can you write me an example?
Do you know how to fix this problem?
Sorry. I don't understand.
anyone?
When you don't have a lot of time those links are useless.

He also doesn't post any work of his own, or display any evidence that he's read any documentation or tried any of the links or advice previously given. Such a person just sounds like a time-sink.

I think you really need to read Eric S. Raymond's excellent guide on how to properly ask questions:

http://www.catb.org/~esr/faqs/smart-questions.html

And please try to understand that I'm not saying these things to be rude, I'm saying them to help you. This is a community where people come together to help each other learn and solve problems. Present yourself in the right way, and you'll be amazed at how friendly and helpful we can be. But selfish and demanding behavior isn't welcome.