Beefy Boxes and Bandwidth Generously Provided by pair Networks
Welcome to the Monastery
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
I wanted to add a bit that I have learned to help you when you start to program and have errors.

It is always good to make sure the file you are opening opens. Because if it doesn't the program will just keep running with no errors and you will not get your desired results. The easiest way to do this is.

open (FILE, "file") || die "file could not be opened";
Then as you program more you will probably do something more like this in all of your programs.

$file = "some_file.txt"; open(FILE,"$file") or &Error($!);
And then at the end of your code where you put your subs put this.

sub Error { $error = shift or $error = "unknown"; print "Sorry, but there was an error. Could not open $file"; print "Error: $error"; &End; }
Another thing that is good to do is to make sure that your close is successful.
close FILE or die "Could not close $file";
And as before you can write special subroutines to help specify your error for closing. This is very helpful when writing CGI scripts and making them look good when they do not open or close files.

LeGo


In reply to RE: File Input and Output by LeGo
in thread File Input and Output by root

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others wandering the Monastery: (1)
As of 2021-10-16 05:28 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    My first memorable Perl project was:







    Results (69 votes). Check out past polls.

    Notices?