Once you are logged onto the BG/P system, you will be sitting at a UNIX shell prompt in your home ($HOME) directory. If you have never used UNIX before, you will need to learn some basic commands before you will be able to submit jobs. A number of links to tutorial information may be found at the Unix Guru Universe Beginners' Pages (external link), particularly the "Getting Started" section. Your account will be set up with the default shell bash, unless you requested a different shell in your account request.
Two other shells are also provided.
You can change your shell by logging in to your account web page. Scroll down to the "Unix Shell" section and choose your new shell.
The BG/P system uses the MCS SoftEnv package to manage access to applications on the machine. The first time a user logs on to BG/P, a '.softenvrc' configuration file will automatically be created in the user's home directory. This file will be set up with the default applications environment -- typically there will be a single line with '@default' in the file. Depending on the user's applications, further modifications to the .softenvrc file may be necessary.
SoftEnv man pages are available in the default environment (use 'man softenv'). The command 'softenv' will list all available applications. Users wishing to gain a more complete understanding of how softenv works may read the complete softenv documentation.
A popular shell provided with the operating system, bash is available as a login shell. To change your login shell use your ALCF personal account page.
Package type: Shell
Known Problems: No known bugs.
Man page (man bash ) - available on any ALCF BG/P system.
Bash online manual located at http://www.gnu.org/software/bash/manual/bashref.html
When and how bash executes startup files.
For Login shells (subject to the -noprofile option): On logging in: If `/etc/profile' exists, then source it. If `~/.bash_profile' exists, then source it, else if `~/.bash_login' exists, then source it, else if `~/. profile' exists, then source it. On logging out: If `~/.bash_logout' exists, source it. For non-login interactive shells (subject to the -norc and -rcfile options): On starting up: If `~/.bashrc' exists, then source it.
For non-interactive shells: On starting up: If the environment variable ENV is non-null, expand the variable and source the file named by the value. If Bash is not started in Posix mode, it looks for BASH_ENV before ENV.