CGI: print a gif directly from a print statement

[meraxes]

I want to have a CGI script return a simple 1x1 transparent gif. However, I wanted to avoid opening the gif file, reading the contents, printing the contents and then closing the file.

I tried this (on a windows nt box), but it didn't work:

print "Content-type: image/gif\n\n";
binmode(STDOUT);
print 0x47, 0x49, 0x46, 0x38, 0x39, 0x61, 0x01, 0x00, 0x01, 0x00, 0x80
+, 0x00, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x2c, 0x00, 0x00, 0
+x00, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x02, 0x02, 0x44, 0x01, 0x00
+, 0x3B;

The print statement is the hex representation of a 1x1 transparent gif file. Why didn't this work and is there something similar I can do?

Many thanks,
meraxes

[impossiblerobot]

All you're printing with your print statement is a list of the decimal equivalents of the hex numbers you've listed (instead of the character representation).
You could use pack, but in the past, I've done this using:


print "\x47\x49\x46\x38 . . .



Impossible Robot

[MZSanford]

Actually, jcrewn just did something similar here as part of a homenode picture rotation program. It should cover the issue.

---

i had a memory leak once, and it ruined my favorite shirt.

[dws]

On Win32, you need to declare binmode before printing "\r\n", otherwise, you'll actually get "\r\r\n", which will confuse the Browser. You also need to pack the bytes.

See On-demand single-pixel GIFs for a working example (it was developed on Win32).

[Anonymous Monk]

Thanks MZSanford, impossiblerobot. I see now the error of my ways :)

Seems I'm going to have to dig deeper into some of my books and do better research before asking these questions.

Thanks,
meraxes