Create a new file with same perms and owner as an existing file

Question

What is the best way to create a new, empty file that has the same ownership and perms as an existing file for a Solaris /bin/sh shell script?

This is for rotating a log file away for compression and dump storage.

At the moment I am using:

mv log log_ts && cp -p log_ts log && cp /dev/null log

Is there a better way to do it?

Update: Unfortunately this is on a conservatively built live Sol10 server and no gnu fileutils are available.

Answer 1

I do this in GNU, I guess it would work on Solaris too:

touch new_file && chmod --reference=old_file new_file

Answer 2

You will need do something like this:

PERM=`ls -l $EXISTING | cut -d" " -f1 | cut -c2- `
PERMU=`echo $PERM |cut -c1-3 | sed s/-//g`
PERMG=`echo $PERM |cut -c4-6 | sed s/-//g`
PERMO=`echo $PERM |cut -c7-9 | sed s/-//g`
chmod u="$PERMU" $TARGET
chmod g="$PERMG" $TARGET
chmod o="$PERMO" $TARGET

Naturally this is for Solaris.