How can I create a simple file versioning via shell script?

Question

Is it possible to make a copy of a file if the content has changed to achieve a simple versioning?

myFolderInclSubfolderBackupWithVersioning.sh < source folder> < dest >

e.g folder on source

• file1.jpg 100K (today)

folder on destination, like external HDD:

• file1.jpg size 100K (today)
• file1(2).jpg size 99K (yesterday)
• file1(1).jpg size 101K (2 monts ago)

Thank you!

Answer 1

The following setting will work:

• a working directory work (can have subdirectories)
• a backup directory backup alongside the working directory (in a real case you might have the backup directory in an external drive)

This command will backup from work to backup:

cp -r --backup=t work/* backup/

Example

$ find
.
./work
./work/file:name
./work/foo.sh
./work/file-0
./work/dollarfraga1
./work/dollarfraga2
./work/sub
./work/sub/hello
./work/dollarfraga
./backup
$ cp -r --backup=t work/* backup/
$ find
.
./work
./work/file:name
./work/foo.sh
./work/file-0
./work/dollarfraga1
./work/dollarfraga2
./work/sub
./work/sub/hello
./work/dollarfraga
./backup
./backup/file:name
./backup/foo.sh
./backup/file-0
./backup/dollarfraga1
./backup/dollarfraga2
./backup/sub
./backup/sub/hello
./backup/dollarfraga
$ cp -r --backup=t work/* backup/
$ find
.
./work
./work/file:name
./work/foo.sh
./work/file-0
./work/dollarfraga1
./work/dollarfraga2
./work/sub
./work/sub/hello
./work/dollarfraga
./backup
./backup/file:name
./backup/dollarfraga1.~1~
./backup/foo.sh
./backup/dollarfraga.~1~
./backup/file-0
./backup/file:name.~1~
./backup/dollarfraga1
./backup/dollarfraga2.~1~
./backup/file-0.~1~
./backup/dollarfraga2
./backup/sub
./backup/sub/hello
./backup/sub/hello.~1~
./backup/dollarfraga
./backup/foo.sh.~1~
$ cp -r --backup=t work/* backup/
$ find
.
./work
./work/file:name
./work/foo.sh
./work/file-0
./work/dollarfraga1
./work/dollarfraga2
./work/sub
./work/sub/hello
./work/dollarfraga
./backup
./backup/file:name
./backup/foo.sh.~2~
./backup/dollarfraga1.~1~
./backup/file-0.~2~
./backup/foo.sh
./backup/file:name.~2~
./backup/dollarfraga1.~2~
./backup/dollarfraga2.~2~
./backup/dollarfraga.~1~
./backup/file-0
./backup/dollarfraga.~2~
./backup/file:name.~1~
./backup/dollarfraga1
./backup/dollarfraga2.~1~
./backup/file-0.~1~
./backup/dollarfraga2
./backup/sub
./backup/sub/hello
./backup/sub/hello.~2~
./backup/sub/hello.~1~
./backup/dollarfraga
./backup/foo.sh.~1~

It is possible to use cp like this, but I would recommend, that you learn rsync, which is a much more advanced tool for copying directory structures including backup, or maybe some dedicated backup tool. rsync and those other tools will only copy files that are new or have changed.