scp not tolerant of extraneous shell messages

[Steve VanDevender]

Bryan Henderson writes:
 > My indication that it is interactive was the fact that it ran .bashrc,
 > which is specifically intended to set up an interactive shell session.

.bash_login is for interactive login sessions.  .bashrc is read by any
invocation of bash.  This is similar to the distinction between .login
and .cshrc in csh.  .bashrc should generate no output.  Commands invoked
in .bash_login can generate output or even prompt for input.