Renaming an Uploaded Picture File
in [Perl]
|
Prev: FAQ 9.23 How do I find out my hostname, domainname, or IP address?
Next: FAQ 5.14 How can I translate tildes (~) in a filename?
From: Doug H on 15 Mar 2010 01:11 Thanks to both repliers. After refering to my ISP web pages about using Perl I discovered that one needs to use use CGI::Carp qw(fatalsToBrowser warningsToBrowser); to have errors display. I tried this and it worked--I got statement errors in the script I was trying. However I could not figure out what the errors actually meant. The statements looked okay to me. Then I had to go to do something else and then this evening when I got back to trying it I could not even get these error messages to show! Very discouraging. I do not even know whether using the above line means that I do not have to use the "use CGI;" line as well. In any case I think I will just have to start from scratch and try to get something to run and show errors if I have them in statements. You said > Dahhh, would have been nice to know this tidbit of information from the > beginning, please see "perldoc -q 500". How does one refer to "perldoc -q 500"? Sorry. I have programmed in octal (in 1958 before there were languages), Fortran, Basic, Visual Basic, COBOL, PL1 but am new to Perl and the book I have been using to learn it, seems to disagree with some of the coding I find on the web. It makes it all very exasperating. Doug
From: J�rgen Exner on 15 Mar 2010 02:31
"Doug H" <courses(a)shaw.ca> wrote: >After refering to my ISP web pages about using Perl I discovered that one >needs to use > >use CGI::Carp qw(fatalsToBrowser warningsToBrowser); > >to have errors display. That is not quite correct. Normally error messages will be sent to STDERR and thus be displayed on the terminal together with STDOUT. However because in a web server environment there is no terminal anything sent to STDERR is being redirect to the error log where it can be examined later at your convenience. The above import shortcuts that method and instead -besides other things- redirects the error messages from STDERR to STDOUT, thus including them in the regular response from the CGI program to the web server. >[...] I could not even get these error messages to show! Did you check the web server's error log? >Very discouraging. I do not even >know whether using the above line means that I do not have to use the "use >CGI;" line as well. CGI and CGI::Carp are two totally different modules. >> Dahhh, would have been nice to know this tidbit of information from the >> beginning, please see "perldoc -q 500". > >How does one refer to "perldoc -q 500"? Sorry. I have programmed in octal perldoc is _the_ standard reference for any Perl command, function, tool, module, you name it. It is automatically installed as part of any (correctly) installed Perl installation and you just call it. Use perldoc perldoc to find out more about the program itself and perldoc perl for a top level overview of what information is available. Some helpful option are perltoc: display table of content -q : search the FAQ -f : display the documentation of a specific function ModuleName: display the documentation for module ModuleName perlop: display list and documentation of all operators in Perl perlsyn: syntax definition for Perl There are numerous other documents available, like a reference tutorial, reference documentation, several OO manuals, regular expression tutorial and manual, and and and. As for "perldoc -q 500" just type that command in at your command line. > am new to Perl and the book I have been using to learn it, seems to >disagree with some of the coding I find on the web. It makes it all very >exasperating. There are quite a few poorly written books and many, many examples of really bad code out there. If you really want to know how something is supposed to work then check out perldoc. It is the ultimate although not always easiest to read reference. And it is always up to date and always matching the version of Perl that you installed. jue |