Hello,
While working on a port of keyringer, I observed the following behavior
of rm(1) with the -P option: if the file does not have write permission,
the file is removed without being overwritten.
This is not the same behavior as shred(1) (from sysutils/coreutils) which do
not remove the file if it cannot be overwritten. If the -f option is
used with shred(1), the permission of the file are changed to allow
writing if necessary.
Is the current behavior desired? (need to update the manpage?)
Or should `rm -P` and `rm -Pf` have the same behavior as shred. That is:
`rm -P` should fail without removing the file if the file cannot be
overwritten and `rm -Pf` should change the permission and overwrite
file.
Here are excerpts from rm(1) and shred(1) manpages:
rm(1)
-f Attempt to remove the files without prompting for confirmation,
regardless of the file's permissions. If the file does not
exist, do not display a diagnostic message or modify the exit
status to reflect an error. The -f option overrides any previous
-i options.
-P Overwrite regular files before deleting them. Files are
overwritten once with a random pattern. Files with multiple
links will be unlinked but not overwritten.
shred(1)
-f, --force
change permissions to allow writing if necessary
And here is a small test to demonstrate this behavior:
$ echo bar > foo
$ chmod -w foo
$ rm -P foo
override r--r--r-- daimrod/wheel for foo? y
rm: foo: Permission denied
$ ls -l foo
ls: foo: No such file or directory
$ echo bar > foo
$ chmod -w foo
$ rm -Pf foo
rm: foo: Permission denied
$ ls -l foo
ls: foo: No such file or directory
$ echo bar > foo
$ chmod -w foo
$ gshred -u foo
gshred: foo: failed to open for writing: Permission denied
$ ls -l foo
-r--r--r-- 1 daimrod wheel 4 Mar 30 17:45 foo
$ gshred -uf foo
$ ls -l foo
ls: foo: No such file or directory
Best,
