[kayson]

> sudo echo $NUM_PAGES > /proc/sys/vm/nr_hugepages

This won't work :) echo will run as root but the redirection is still running as the unprivileged user. Needs to be run from a privileged shell or by doing something like sudo sh -c "echo $NUM_PAGES > /proc/sys/vm/nr_hugepages"

The point gets across, though, technicality notwithstanding.

[thayne]

Or

    echo $NUM_PAGES | sudo tee /proc/sys/vm/nr_hugepages 

I've always found it odd that there isn't a standard command to write stdin to a file that doesn't also write it to stdout. Or that tee doesn't have an option to supress writing to stdout.

[axiolite]

You forgot the "sudo" before "tee"

> write stdin to a file that doesn't also write it to stdout

You mean like "dd of=/path/file" ?

[zdragnar]

I physically/literally squinted when I saw disk destroyer.

I know it's useful for other things, but it has become a fearful instinct at this point.

[goestin]

If my memories serves me right it was meant to be "Copy Convert" but "cc" was already taken for "C Compiler" so they went to the next letter in the alphabet (alpha beta), hence "dd". Thanks for listening to my TED talk of useless and probably false information :)

edit: i will be stealing disk destroyer, though

[axiolite]

    According to Dennis Ritchie, the name is an allusion to the DD statement found in IBM's Job Control Language (JCL), where DD is short for data definition  https://en.wikipedia.org/wiki/Dd_%28Unix%29#History

[vbezhenar]

I've always thought that there should be `cat -o output-file` flag for that. GNU coreutils have miriads of useless flags and missing one actually useful flag LoL.

And probably `echo -o output-file` as well.

[TheDong]

> I've always found it odd that there isn't a standard command to write stdin to a file that doesn't also write it to stdout

If you happen to have moreutils installed, you can do that with pee

    echo $NUM_PAGES | sudo pee 'cat > /proc/sys/vm/nr_hugepages'

[direwolf20]

why not write sh -c then?

[TheDong]

Because 'sh' isn't in moreutils and is harder to remember, next question.

Why use something portable when you can use cat pee?

[semiquaver]

Personally? Because I hate the smell.

[wang_li]

It’s not an option or feature because it’s built into the shell. Just slap a > /dev/null on the end.

[thayne]

That works, but it feels wasteful to needlessly copy it, and it is verbose.

[timetoogo]

Great point, I was running as root so I didn't pick this up. Corrected, thank you!