Re: Re: The specified CGI application misbehaved by not returning acomplete set of HTTP headers.

Your suggestion to redirect stderr to stdin works splendid. On Mon, 2004-03-22 at 12:44, DvDmanDT wrote: > I would suspect popen() happends to output STDERR, and that dir returns some > STDERR when no files are found, or when the argument is invalid.. And if so, > the STDERR message would get output directly to the webserver, and if it > contains two newlines (which it does really I think), the webserver wouldn't > get a complete set of headers (which it's complaining about)... > > Add this at the end of your command: 2 > &1, like this: > > $ListDir = "dir $Dir\\*.$pattern 2>&1"; > > Also, I think this would be even better: > $ListDir = "dir \"$Dir\\*.$pattern\" 2>&1"; > > Happy coding! > -- > // DvDmanDT > MSN: dvdmandt$hotmail.com > Mail: dvdmandt$telia.com > "B.A.T. Svensson" <B.A.T.Svensson@lumc.nl> skrev i meddelandet > news:1079951719.30259.138.camel@ander... > > I am curious about why the following error: > > > > > > "The specified CGI application misbehaved by not returning a complete > > set of HTTP headers." > > > > is generated while trying to read data from an empty pipe. > > > > > > > > ********************************************************** > > > > DISCUSSION: > > > > I have an (working) application that renders an out put in > > side a table based on the menu selection the user does. > > > > Basically the web pages is organized as such: > > > > +-----------+ > > | PAGE HEAD | > > +-+---------+ > > |M| | > > |E| OUTPUT | > > |N| VIEW | > > |U| | > > . . . > > . . . > > . . . > > +-+---------+ > > | PAGE FOOT | > > +-----------+ > > > > > > > > Now, if I select a certain menu choices, and the system is in a > > certain state (will soon explain this) then the CGI error "The > > specified CGI application misbehaved by not returning a complete > > set of HTTP headers." occurs. > > > > What trigger then the error then, well, it is derived from a > > function like this: > > > > (This function will output its display data the "OUTPUT VIEW".) > > > > function ug_show_files($Dir, $pattern, $Message) > > { > > print "<pre>$Message\r\n"; > > > > $ListDir = "dir $Dir\\*.$pattern"; > > if ($pipe = popen($ListDir, "r")) { > > > > while (!feof($pipe)) { > > $line = trim(fgets($pipe)); > > print "$line\n"; > > } > > > > pclose($pipe); > > } > > > print"<pre>"; > > return "ok"; > > } > > > > The above code list a given directory based on $pattern. > > However whenever no files are found, then the above CGI error > > is generated - but never if there is a content found. I was a > > bit confused about this, since the only difference is that the > > directory listing does not generate an output, so in my point > > of view it should work, but it did not. > > > > > > I boiled down the problem to be related with fgets() - the error > > occurs when the directory listing does not return anything, so I > > thought I would be able to get rid of the error by writing the code > > like this instead: > > > > function ug_show_files($Dir, $pattern, $Message) > > { > > print "<pre>$Message\r\n"; > > > > $ListDir = "dir $Dir\\*.$pattern"; > > if ($pipe = popen($ListDir, "r")) { > > > > $a = fgets($pipe) > > while (!feof($pipe)) { > > $line = trim($a); > > print "$line\n"; > > $a = fgets($pipe); > > } > > pclose($pipe); > > } > > > print"<pre>"; > > return "ok"; > > } > > > > > > However the error persisted whenever the directory list > > was empty so I changed the code to look like this: > > > > function ug_show_files($Dir, $pattern, $Message) > > { > > print "<pre>$Message\r\n"; > > > > $ListDir = "dir $Dir"; > > if ($pipe = popen($ListDir, "r")) { > > > > while (!feof($pipe)) { > > > > $line = trim(fgets($pipe)); > > if (strpos($line, ".$pattern")) { > > print "$line\n"; > > } > > > > } > > pclose($pipe); > > } > > > print"<pre>"; > > return "ok"; > > } > > > > And after this the pages stop returning an error. Now to the > > question; why is it that fgets() generates this CGI error > > when fgets() read from an empty pipe?