If you're interacting with stateful systems (which you usually are with this kind of command), --dry-run can still have a race condition. The tool tells you what it would do in the current situation, you take a look and confirm that that's alright. Then you run it again without --dry-run, in a potentially different situation. That's why I prefer Terraform's approach of having a "plan" mode. It doesn't just tell you w…
Totally agree, and this is covered in an (identically named?) Google Research blog [1].
Just last week I was writing a demo-focused Python file called `safetykit.py`, which has its first demo as this:
def praise_dryrun(dryrun: bool = True) -> None:
...
def gather(paths):
files = []
for pattern in paths:
files.extend(glob.glob(pattern))
return files
def execute(files):
for f in files:
os.remove(f)
files = gather([os.path.join(tmp_dir, "*.txt")])
if dryrun:
print(f"Would remove: {files}")
else:
execute(files)