🚀 go-pugleaf

In article <FRIEDMAN.92Jul24055302@nutrimat.gnu.ai.mit.edu> friedman@gnu.ai.mit.edu (Noah Friedman) writes:
: This is at least one way to (almost) do locking in pure shell script.  I
: suspect other methods are probably more difficult, if not also presently
: impossible.  However, you can write a small C program to do the atomic
: exclusive file creation, returning an exit status that indicates whether it
: succeeded or failed.  Then the rest can probably be done in shell script
: (depending on what else you want to do, that is).
: 
:    Tom or Larry: can perl do this correctly?

I believe exclusive open is actually fairly useless in the presence of
certain Network File Silesystems which shall go unnamed, but perl does
give you access to either flock() or lockf() (the latter via ioctl()).
For a really safe atomic operation, though, use link--I don't think
anyone's found a way to botch that up yet.  But I could become wrong.

Larry Wall
lwall@netlabs.com