On Mon, Jun 20, 2011 at 08:39:00PM +1000, Adam Carter wrote:
> >> /bin/sh is a symlink to bash.
> >
> > Which runs as sh when run from the symlink.
>
> I dont understand. "runs as" usually means "runs under the user
> context" to me - are you saying bash has an sh compatibility mode?
Yes, from the bash man page:
If bash is invoked with the name sh, it tries to mimic the startup
behavior of historical versions of sh as closely as possible, while
conforming to the POSIX standard as well. When invoked as an interac‐
tive login shell, or a non-interactive shell with the --login option,
it first attempts to read and execute commands from /etc/profile and
~/.profile, in that order. The --noprofile option may be used to
inhibit this behavior. When invoked as an interactive shell with the
name sh, bash looks for the variable ENV, expands its value if it is
defined, and uses the expanded value as the name of a file to read and
execute. Since a shell invoked as sh does not attempt to read and exe‐
cute commands from any other startup files, the --rcfile option has no
effect. A non-interactive shell invoked with the name sh does not
attempt to read any other startup files. When invoked as sh, bash
enters posix mode after the startup files are read.
W
--
Willie W. Wong ww...@math.princeton.edu
Data aequatione quotcunque fluentes quantitae involvente fluxiones invenire
et vice versa ~~~ I. Newton
