Shell Script — Get all files modified after <date>

Question

as simple as:

find . -mtime -1 | xargs tar --no-recursion -czf myfile.tgz

where find . -mtime -1 will select all the files in (recursively) current directory modified day before. you can use fractions, for example:

find . -mtime -1.5 | xargs tar --no-recursion -czf myfile.tgz

If you have GNU find, then there are a legion of relevant options. The only snag is that the interface to them is less than stellar:

• -mmin n (modification time in minutes)
• -mtime n (modification time in days)
• -newer file (modification time newer than modification time of file)
• -daystart (adjust start time from current time to start of day)
• Plus alternatives for access time and 'change' or 'create' time.

The hard part is determining the number of minutes since a time.

One option worth considering: use touch to create a file with the required modification time stamp; then use find with -newer.

touch -t 200901031231.43 /tmp/wotsit
find . -newer /tmp/wotsit -print
rm -f /tmp/wotsit

This looks for files newer than 2009-01-03T12:31:43. Clearly, in a script, /tmp/wotsit would be a name with the PID or other value to make it unique; and there'd be a trap to ensure it gets removed even if the user interrupts, and so on and so forth.

You can do this directly with tar and even better:

tar -N '2014-02-01 18:00:00' -jcvf archive.tar.bz2 files

This instructs tar to compress files newer than 1st of January 2014, 18:00:00.

This will work for some number of files. You want to include "-print0" and "xargs -0" in case any of the paths have spaces in them. This example looks for files modified in the last 7 days. To find those modified before the last 7 days, use "+7".

find . -mtime -7 -print0 | xargs -0 tar -cjf /foo/archive.tar.bz2

As this page warns, xargs can cause the tar command to be executed multiple times if there are a lot of arguments, and the "-c" flag could cause problems. In that case, you would want this:

find . -mtime -7 -print0 | xargs -0 tar -rf /foo/archive.tar

You can't update a zipped tar archive with tar, so you would have to bzip2 or gzip it in a second step.