bfox@AUREL.CALTECH.EDU (Brian Fox) (07/20/89)
Date: Wed, 19 Jul 89 09:03:56 EDT
From: barratt@dash.mitre.org (Jeff Barratt)
Brian,
Nice job on bash.
We're running v1.02 on Sun 3's w OS4.01.
Problem: "declare -x" and "typeset -x" do NOT seem to export. A
separate "export vars" is required.
Thanks. This turned out to be a simple problem and fix. In
builtins.c, function declare_internal (), the lines which read
else if (*t == 'x')
*flags |= att_exported, t++;
needs to have "array_needs_making = 1" added to it.
else if (*t == 'x')
*flags |= att_exported, t++, array_needs_making = 1;
This tells bash that the list of exported variables has changed, and
needs to be recalculated.
Question: Could you elaborate on the startup execution of default
files. It appears that initial login runs "~/.bash_profile", and
subsequent shells run "~/.bashrc". What about
"~/.bash_(login,logout)"?
Sure, and since you aren't the first to ask about this, I'll take a
little time to make sure I document it clearly. The follwing is the way
that Bash 1.03 (pre-release) does it. Earlier releases have the
exception of not having the "ENV" variable, and of executing ~/.bashrc
for shell scripts.
When and how bash executes login, rc, and logout files.
Login shells:
On login:
if /etc/profile exists, source it.
if ~/.bash_profile exists, source it,
else if ~/.bash_login exists, source it,
else if ~/.profile exists, source it.
On logout:
if ~/.bash_logout exists, source it.
Non-login interactive shells:
On startup:
if ~/.bashrc exists, source it.
Non-interactive shells:
On startup:
if the environment variable "ENV" in non-null, source the file
mentioned there.
So, typically, your ~/.bash_profile file contains the line
if [ -f ~/.bashrc ]; then source ~/.bashrc; fi
after (or before) any login specific initializations.
You can tell if a shell is interactive or not from within your ~/.bashrc
file by examining $PS1; it is unset in non-interactive shell, and set in
interactive shells. Thus:
if [ "$PS1" = "" ]; then
echo This shell is not interactive
else
echo This shell is interactive
fi
Thanks,
Brian Fox