sprintf function 2

[jisoo22]

Hello!

I'm having a little trouble with the sprintf() function. What I'm trying to do is create a random number with the rand() function and then turn it into a non-fractional integer (ie 2 instead of 2.5 or whatever). The problem is that I don't quite understand the syntax for the sprintf function. Should my statement be like this:

$random = sprintf(%2c, $random);

Please let me know asap.

Thanks!
Jisoo22

 

[raider2001]

Why don't you use the "int" function?

$Random=int(rand $Max);

 

[raider2001]

Or you could use:

$random=(sprintf "%d", $random);

 

[tsdragon]

Unless you need a formatted number for printing, the int function raider2001 mentioned is probably the best way to go, especially if you want a whole number between 1 and n, and use the int(rand n) form. Note: if you DON'T use a maximum value and you use int, all you will ever get is 1! Tracy Dryden
tracy@bydisn.com

Meddle not in the affairs of dragons,
For you are crunchy, and good with mustard.

 

[jisoo22]

Thanks for the suggestions! I couldn't use "int" before because I read somewhere that it doesn't do rounding. The basic premise of my little perl script is to open up a text document, count the number of lines of text within it, then randomly pick a line and display it. Unfortunately for me the "rand" function that gives me the random line number only gives back floats, so I'd most likely get a partial number like 2.57. So I'm guessing the "Sprintf" statement is the best way to go, correct?

 

[jisoo22]

P.S. Does anyone know the correct statement for printing out the contents in the line number? Is it printf?

Thanks,
Jisoo22

 

[tsdragon]

If you choose a random number between 0 and the number of lines in the file, you don't NEED to round it, Just use int to truncate it, and add 1.

printf will format and print a number. sprintf will format a number and store it in a string, from which you can print it later. Either one will work. Tracy Dryden
tracy@bydisn.com

Meddle not in the affairs of dragons,
For you are crunchy, and good with mustard.

 

[jisoo22]

Ah that clears things up, thanks =) One thing about the printing though, I think I gave the wrong idea! My fault! I want to print what's actually on that line number instead of the actual line number itself. (i.e. it would print out "This is in line 1" if I selected 1). Would printf of sprintf still work?

 

[raider2001]

If you aren't doing any formatting, "print" is the function you want. For formatting, use "printf".

 

[tsdragon]

Unless you need to format a number, just use print. As you read the contents of the text file, store them in an array (say @lines). Then you can print a random line with:

print $lines[rand $#lines],"\n";

In this case you really don't even need the int function, since perl will ignore the fractional part of the subscript anyway. Tracy Dryden
tracy@bydisn.com

Meddle not in the affairs of dragons,
For you are crunchy, and good with mustard.