Re: SCP Recursive Flag

[Pádraig Brady]

On 03/27/2014 02:24 PM, Colton Peltier wrote:
> Hi,
> 
> While working with some coworkers recently we noticed a strange inconsistency 
> between cp and scp, that caused us some confusion. For the cp tool a -r or -R 
> will do a recursive copy of directories, but for scp only -r will. The -R 
> flag for scp is gives illegal option. What is the reasoning behind this?

cp accepts the non standarized -r for historical reasons.
It's synonymous with the POSIX standardized -R.
Interestingly for rm, POSIX has standardized that -r is equiv to -R.

FreeBSD cp treats -r a bit differently and has this to say in the man page:
  Historic versions of the cp utility had a -r option.  This implementation
  supports that option, however, its behavior is different from historical
  FreeBSD behavior.  Use of this option is strongly discouraged as the
  behavior is implementation-dependent.  In FreeBSD, -r is a synonym for
  -RL and works the same unless modified by other flags.  Historical imple-
  mentations of -r differ as they copy special files as normal files while
  recreating a hierarchy.

scp only accepts -r as it's a separate util not standardized by POSIX.
BTW the openssl utils options can be quite inconsistent and confusing:
  ssh -P22  # use privileged port, use protocol version 2
  ssh -p22  # use port 22
  scp -P22  # use port 22

Pádraig.