Portable (cartesian) brace expansion in your shell

5 points by mqudsi

LeahNeukirchen

This doesn't work at all, and neither is a proper cartesian product of two sets...

pl
Hm, it works for me (as long as there are no spaces or newlines in filenames)
```
touch /tmp/{hello,world,"hello world"}
ls $(printf '/tmp/%s\n' "hello" "world" "hello world")
ls: cannot access 'world': No such file or directory
/tmp/hello  /tmp/hello  /tmp/world
```
Using \n in the printf doesn't really help, and quoting either + it would not pass shellcheck.

but a funny workaround nevertheless

use echo instead of printf if your $IFS configuration splits on spaces

Isn't IFS only for loops? Oh no it isn't. I never touch IFS :D but TIL. Wild.
```
IFS=:
ls $(printf '/tmp/%s:' "hello" "world" "hello world")
/tmp/hello  '/tmp/hello world'   /tmp/world
```

tmcb

Bash at least also supports empty values in the expansion. I use it all the time to create backups with mv file{,.old}.

jmtd

I’d like to try {mkdir,chown,chmod} /var/log/{foo,bar,baz}