[email protected] wrote:
> (info "(coreutils) Backup options") should add some examples, for
> "So how do we make a backup file of m?"
> $ ls
> m
> $ cp -b m m #no go
Thanks for the suggestion.
I use this zsh/bash shell function:
backup ()
{
local i
for i in "$@"; do
command cp -bf "$i" "$i"
done
}
but as I inserted the above, I realize it's buggy.
It doesn't propagate failure like you'd expect,
so here's a better one:
backup()
{
local i fail=0
for i in "$@"; do
command cp -bf -- "$i" "$i" || fail=1
done
return $fail
}
That's already almost what info coreutils says:
Make a backup of each file that would otherwise be overwritten or removed.
As a special case, @command{cp} makes a backup of @var{source} when the force
and backup options are given and @var{source} and @var{dest} are the same
name for an existing, regular file. One useful application of this
combination of options is this tiny Bourne shell script:
@example
#!/bin/sh
# Usage: backup FILE...
# Create a @sc{gnu}-style backup of each listed FILE.
for i; do
cp --backup --force -- "$i" "$i"
done
@end example
I'll adjust that to reflect the above improvement:
Do you think that's enough?
> $ cp m n
> $ mv -b n m
