mv command - don't overwrite files

Question

I want to mv files and not overwrite duplicates. The -b switch only makes a single backup file, whereas I may have many.

According to the mv man page:

The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX. The version control method may be selected via the --backup option or through the VERSION_CONTROL environment variable. Here are the values:

none, off: never make backups (even if --backup is given)
numbered, t: make numbered backups
existing, nil: numbered if numbered backups exist, simple otherwise
simple, never: always make simple backups

I think I want to use the 'existing, nil' option... but I can't figure out how to call that.

If my command is:

mv $src $dest

How can I implement the 'existing, nil' option?

This answer has a good response about using cp instead of mv: http://unix.stackexchange.com/a/9902 — Connor Leech, Oct 26 '15 at 01:20

score 8 · Accepted Answer · answered Jan 23 '15 at 19:01

To enable existing or nil (or any of the other options), pass them as values for the --backup option:

mv --backup=existing "$src" "$dest"
mv --backup=nil "$src" "$dest"

Be warned that this does not do what you want:

$ mkdir foo bar
$ cp blah/* foo
$ cp blah/* bar
$ mv --backup=nil bar/* foo/* -t blah
mv: will not overwrite just-created ‘blah/a.jpg’ with ‘foo/a.jpg’
mv: will not overwrite just-created ‘blah/b.ogv’ with ‘foo/b.ogv’
mv: will not overwrite just-created ‘blah/cd ef.JpG’ with ‘foo/cd ef.JpG’

You actually want numbered/t:

$ mv --backup=numbered bar/* foo/* -t blah
$ ls blah 
a.jpg  a.jpg.~1~  a.jpg.~2~  b.ogv  b.ogv.~1~  b.ogv.~2~  cd ef.JpG  cd ef.JpG.~1~  cd ef.JpG.~2~

that seems really cryptic. What is the backup option for? – Connor Leech Oct 26 '15 at 01:21 — Connor Leech, Oct 26 '15 at 01:21
@ConnorLeech to control the backup settings? – muru Oct 26 '15 at 04:08 — muru, Oct 26 '15 at 04:08

score 0 · Answer 2 · answered Jan 23 '15 at 19:00

0

mv --backup=existing $src $dest

or

mv --backup=nil $src $dest

answered Jan 23 '15 at 19:00

Florian Diesch

87,389

After many attempts, I got the syntax working -- but the nil option did not work. --backup=t does though. THANKS! – BeMy Friend Jan 23 '15 at 19:05

score 0 · Answer 3 · edited Jan 23 '15 at 19:10

0

mv --backup=t "$src/$file" "$dest"

edited Jan 23 '15 at 19:10

muru

197,895
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485
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answered Jan 23 '15 at 19:04

BeMy Friend

1,093

for details see man mv – Elder Geek Jan 23 '15 at 20:46

mv command - don't overwrite files

3 Answers3