Richard Luckhurst wrote:
Hi AllI am a perl newbie. I have a small perl script that is actually a cgi-bin script. I am told that until a recent server change over it ran fine however now it produces no output. I have tried running it from a command line and redirecting the input it would have received as a cgi-bin script from a text file. I am getting a couple of "Use of uninitialized value in concatenation (.) or string" errors and I can not see why. The script is as follows #!/usr/bin/perl # # log-errors cgi-bin script to display the last 2000 lines of an error log. # domain is the domain name of the virtual apache server # require '/www/server/cgi-bin/cgi-lib.pl'; &ReadParse(*in); $domain = $in{'domain'}; print "Content-type: text/html\n\n"; print "<html><head><title>Exodus Web Server Log</title></head>\n"; print "<body link=\"blue\" vlink=\"blue\">\n"; print "<font size=\"4\"><b>Last 2000 Lines of the Error log for: $domain</b></font><br>\n"; print "<font size=\"1\"><br></font>Go to <a href=\"#bottom\"><i>End of log</i></a><br><br>\n"; $tail = `tail -n2000 /var/log/httpd/$domain-error_log 2>/dev/null | tac`; $tail =~ s/</<\;/g; $tail =~ s/>/>\;/g; print "<pre>$tail<\/pre>\n"; print "<a name=\"bottom\"></a>"; print "<br><b>End of log</b><br>\n"; print "</body></html>\n"; exit 0; When I run the script from the command line with the command perl -w log-err* < test.txt Where test.txt contains domain=www.resmaster.com I get the following output Content-type: text/html <html><head><title>Exodus Web Server Log</title></head> <body link="blue" vlink="blue"> Use of uninitialized value in concatenation (.) or string at log-errors line 10. <font size="4"><b>Last 2000 Lines of the Error log for: </b></font><br> <font size="1"><br></font>Go to <a href="#bottom"><i>End of log</i></a><br><br> Use of uninitialized value in concatenation (.) or string at log-errors line 12. <pre></pre> <a name="bottom"></a><br><b>End of log</b><br> </body></html> It seems that the value of the domain is not being passed in correctly and it is not being passed down through the script. When I run the script as a cgi-bin script called from a web page I get the html code produced by the print statements but I get nothing from the $tail variable. This is what I would expect as I get nothing between the <pre></pre> tags when I run it from a command line. I would appreciate any help in sorting out this problem.
Hello Richard You are right that your problem is almost certainly because $domain is not being set up properly, but the error lies in the ReadParse() subroutine in the cgi-lib.pl file which you don't show. You are looking at a very old piece of Perl programming which is doing things in ugly ways, so please don't try to learn anything from its methods! Rob -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] <http://learn.perl.org/> <http://learn.perl.org/first-response>
