What does “wget -O” mean?

Question

I have an wget command like this in my shell script:

reponse=\"`wget -O- http:localhost:8080/app/index.html`\"

I don\'t understand the -O-

Answer 1

Depending on your system you should be able to find reference by typing man wget. The GNU Wget man page says this of the -O|--output-document flag:

If - is used as file, documents will be printed to standard output, disabling link conversion. (Use ./- to print to a file literally named -.)

And continues…

Use of -O is not intended to mean simply "use the name file instead of the one in the URL;" rather, it is analogous to shell redirection: wget -O file http://foo is intended to work like wget -O - http://foo > file; file will be truncated immediately, and all downloaded content will be written there.

It's not uncommon to see combined with -q and written as -q0- or -q0 - followed by a uri. It validates against the POSIX standard so, yeah, I'd say it's a standard thing for shell scripting.