Hi,

The reason for the topic title is because I'l be asking various questions in the same thread over a period of time, easier then making a million threads!

Anyway, I'm having a problem with one of my scripts.

What I want to do is read a file that the user inputs.
E.g - stats.txt will open the file.

However, what i want to do, is that if the user doesn't enter a extension of .txt it will automatically add it.

My attempt:

However, this doesn't work. =[

Any help is greatly appreciated.

Saying "it doesn't work" is not very helpful. Post any error messages or warnings the script outputs or describe what the script does do.

In your case I see one problem right away:



$file will end with an input terminator, probably a newline, so it will not be able to open a file named "file.txt\n" which your die statment should have caught and echoed back an error. You need to use chomp() on your input:



from now on, start all your perl script with these two pragmas:



and you can add this one for good measure:



The first two are very important, especially for new perl coders. The third one dplays very verbose messages and is sometimes more useful than the brief messages that perl outputs by default.

If your perl resource material did not mention the need to chomp() input, I would stop using it.

Besides all that, your script looks like it should work once the chomp() is added.

Kevin

Apologies.

Whether we have the:



Or not, we can still bring up the .txt document by typing in the extension.

After adding the warnings, strict and diagnostics, and then running the script again.Without supplying the extension i am faced with the following error.
(BTW, I am using the command line);



With the code being ultimately altered to:

change this line:



to:



$! stores the operating system error message, which you will need to see why the file is not being opened by the perl script. Where are you learning perl from? This is quite useless:

die "Dead";

I hope your perl resource material did not suggest using that useless construct. You should also use the lower precedence "or" for program flow control instead of "||".

I used the:

die "Dead";

As i didn't think it mattered what i actually printed at this time?
Oh so i understand why the $! is now used, thanks.

The error message is now:



This post has been edited by josephman1988: 7 Jul, 2007 - 11:08 AM

The problem is that file "stat" can't be found. I would think you would want to check/add the "txt" extension before trying to open the file. Also, the file has to be in the same directory as the script if you don't use a path to the file when you try and open the file.

I'll check back later, I've got stuff to do.

Omg, trust it to be a simple snippet of code being added in the wrong place.

Thanks for the help mate.

Appreciate your time. =]

If i wanted to put in another feature, where the user has to input a filename with only letters, would i have to put this in the same code block or a separate on?

For E.g -
until ($file =~ m/[a-zA-Z])

How would i repeat this process until the user inputs a valid set of characters?
Would i use a 'redo LOOP:' method or what?

Thanks.

Well, there are a number of ways to do something like this. You sort of have the correct concept. The regexp is not correct though because it is only checking to see if there is at least one of those characters any where in the string. To check the entire string you have to use string anchors:

^ (beginning of string)
$ (end of string)



the {10,20} checks for a min and max length.

That worked like a charm. =]

Last question on this matter I promise!

Say the text file being read has 2 paragraphs, being separated by 2 newlines.

How would I count the paragraphs in the text file and print the results?

One way is to change the input record seperator to "\n\n"

I managed to find a simple way.


But now I'm really confused?
I want to count characters in the file, whitespace and a-z only.
As well as words and sentences.

So i tried the following for words

$c++ if (m/^\w+\s+/);
- This actually counts the lines excluding paragraphs -

Don't know how to count single characters and words though?