Bash scripting problems
Matthew Miller
mattdm at mattdm.org
Sat Jan 8 21:45:21 UTC 2005
On Sat, Jan 08, 2005 at 05:39:58PM -0400, Jorge Fábregas wrote:
> On Saturday 08 January 2005 1:28 pm, Alexander Dalloz wrote:
> > sh != bash
> Hello there!
> I wouldn't say so :)
> sh is actually a link to bash.
> ls -l /bin/sh
> lrwxrwxrwx 1 root root 4 Jul 2 2004 /bin/sh -> bash
Yes, but bash acts differently in that case:
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
interactive 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 execute 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.
--
Matthew Miller mattdm at mattdm.org <http://www.mattdm.org/>
Boston University Linux ------> <http://linux.bu.edu/>
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