Forum OpenACS Q&A: Re: Help for using HTMLDOC to output pdf file/download pdf file

Running exec on htmldoc would successfully execute the shell commands, but return this error:

  child process exited abnormally

This would ruin my ns_returnfile since output was sent to the browser before the 200 header.

I discovered htmldoc returns 1 on success to stdout which is returned by catch and exec. Just catch the error and do nothing with it.

# Download the pdf
set file_name_pdf [ns_tmpnam]
append file_name_pdf ".pdf"

if {[catch {exec echo \ $html\  | /usr/share/htmldoc/htmldoc --webpage --quiet -f $file_name_pdf -} errmsg]} {
#Do nothing with the error and we're good.

ns_returnfile 200 application/pdf $file_name_pdf

return filter_return

Oh, and concerning the strangeness with
  echo \[space]$html\[space]
This is the only way to simulate shell quotes with exec. Curly braces and \" do not seem to work. Remember that $html must be escaped - "[{ etc!

More info on exec:

Hope this helps someone.