On Wed, Mar 20, 2019 at 07:49:34AM +0700, Robert Elz wrote: > However, using files for here docs makes here docs unusable in a shell > running in single user mode with no writable filesystems (whatever is > mounted is read only, until after file system checks are finished).
Meanwhile, proposals based around /dev/fd/* would also make here docs unusable in a shell running early in the boot process, before all file systems are mounted. Just like that one time L. Walsh tried to write a bash boot script that used <() to populate an array, and it failed because she was running it too early in the boot sequence, and /dev/fd/ wasn't available yet. So, my counterpoints are: 1) Leave it alone. It's fine. 2) Don't use bash for scripts that run early in the boot sequence. 3) Whatever features you *do* use in boot scripts, make sure they're available at the point in the boot sequence when the script runs. 4) Whatever features you use in scripts *in general*, make sure you understand how they work. Even if Chet changed how here docs work in bash 5.1, nobody would be safe to use those features in their "I'm feeding a password with a here string" scripts for at least 20 years, because there will still be people running older versions of bash for at least that long. Thus, leave it alone.
