why curl can't expand variable inside the loop, but echo can?

Question

I need to include variable inside curl

for fname in "assets/*.drx"; do
    echo $fname
    curl -F file=@"$fname" "http://someurl.com/"    
    echo $fnamename
done

Result:

assets/5baa5caa414f1d7786e86d03_1545903119.11.drx
curl: (26) couldn't open file "assets/*.drx"
assets/5baa5caa414f1d7786e86d03_1545903119.11.drx

It seems curl uses glob expression, but echo uses actual filename. Why does curl behave like this? Why does echo see the actual variable and how can I use the filename inside curl?

Answer 1

You've quoted the * wildcard, preventing the shell from expanding it.

for fname in assets/*.drx; do
    printf '%s\n' "$fname"
    curl -F file=@"$fname" "http://someurl.com/"    
done

The fname variable was assigned the literal text assets/*.drx. When you used it unquoted in the echo, the shell dutifully expanded it.