Yes, it is. In fact, there are several files read when a session/shell starts:

Whenever a session starts (that is: a user logs in), a system profile is read. In most systems this is called "/etc/environment" (AIX) or "/etc/profile" (SunOS, Linux).

Then a user profile is read. On most systems it is called ".profile" and resides in the users "$HOME". Commonly in "~/.profile" a variable named "ENV" is set, which names the startup file for the shell.

After these two files the shell itself is started. Which one this is depends on the user entry in the file "/etc/passwd", which is readable by everyone. "grep" it for you own username, which will possibly look similar to:

Code:

# grep username /etc/passwd
username:x:1001:1001:username,,,,:/home/username:/bin/ksh

The last entry is the path the shells executable, in this case Korn shell.

The following part of the process is executed every time a shell starts. This is the case for every log-in-process, because as the last stage of the log-in a shell is started, but also when a script is started with a shebang ("#!") in the first line, you enter "ksh" ("bash", ...) on the command line, etc..

First, the shell reads a system-dependant startup-file. In linux (and with bash) this is "/etc/bashrc", other system/shell-combinations may have different startup files. A look in the man page of your shell will tell you which one it is.

Second, a user-dependant startup file is read. This is either the file declared via the "ENV" variable (see above) or a default file: for bash it is "~/.bashrc", for ksh it is "~/.kshrc", etc.

Every later file can override settings from an earlier run file. Because i don't like all these graphical gimmicks like coloured ls-output my startup-files on Linux systems usually are full with commands unsetting the "helpful" aliases and other fancinesses the "/etc/profile" is setting. This may seem inefficient (first setting a lot of things, than reset all these setting to zero), but i don't like to change the "original" look and feel of the Linux systems by changing the system-wide settings. This way it is only my own account which behaves like i think a Unix-account should behave.

I hope this helps.

bakunin