I am trying to pipe a jpg filename to the Image Magick display command. As in “cat myfile | display”. “myfile” contains a jpg filename. It returns the error “display: no decode delegate for this image format `/tmp/magick-XXPOGHGV’ @ error/constitute.c/ReadImage/532”. What am I doing wrong? If I invoke display with the jpg filename, it works just fine.
Thanks.
Reading
man display
I see that it should be invoked as
display [options] input-file
Thus the input file is a field in the command line. What you do is sending text to stdin of the display program, but nowhere is said that it does read anything from stdin.
I guess it will work when you do
display $(cat myfile)
or even shorter
display $(<myfile)
On 2011-10-03 22:26, ionmich wrote:
>
> I am trying to pipe a jpg filename to the Image Magick display command.
> As in “cat myfile | display”. “myfile” contains a jpg filename. It
> returns the error “display: no decode delegate for this image format
> `/tmp/magick-XXPOGHGV’ @ error/constitute.c/ReadImage/532”. What am I
> doing wrong? If I invoke display with the jpg filename, it works just
> fine.
Not all programs accept input that way.
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” at Telcontar)
On Mon, 03 Oct 2011 20:26:03 +0000, ionmich wrote:
> If I invoke display with the jpg filename, it works just fine.
Piping the name in from a file is not the same as invoking with the
filename.
What you’re doing is telling it the contents of the file are the image
data.
Jim
–
Jim Henderson
openSUSE Forums Administrator
Forum Use Terms & Conditions at http://tinyurl.com/openSUSE-T-C
Thank you very much. My incorrect assumption was that “display” accepts stdin. I will be more careful in future.