Re: [Gnuplot-info] gnuplot as cgi - output http headers

[Leo B. <l_b...@us...>]

>   I am wondering  if it is possible to make gnuplot to output
>   "Content-Type: image/svg+xml" to use gnuplot scripts directly with cgi.
>
>   E.g. for this
>
>	   #!/usr/bin/gnuplot
>	   set terminal svg
>	   plot sin(x)
>
>   I  currently have to use a wrapper:
>
>	   #!/bin/bash
>	   echo "Content-Type: image/svg+xml"
>	   echo
>	   $PWD/myplot.gnu

If you set up a naming convention, this can be made to work. Call your
script graphics.sh and for each gnuplot script, foo.gnu, have a
symlink foo.sh to graphics.sh. Change the last line to

gnuplot ${0/%gnu/sh}

Now only one script is needed.

>
>   But having a wrapper script for each gnuplot script is not ideal.
>   I tried to add this to the gnuplot script:
>
>	   print "Content-Type: image/svg+xml"
>	   print ""
>
>   but then this goes to STDERR instead of STDOUT so next I also added
>
>	   set output "STDOUT"
>
>   but then only the header is displayed and the svg data is missing.


set output "STDOUT"

redirects the output to a file named STDOUT.
The following works for me. All output is sent to stdout.

# send printed output to stdout
set print "-"
print "Content-Type: image/svg+xml"
print ""
set terminal svg
plot [0:2*pi] sin(x)

Leo