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Full Discussion: Environment variables
Top Forums Shell Programming and Scripting Environment variables Post 302631099 by jim mcnamara on Thursday 26th of April 2012 07:38:49 PM
Old 04-26-2012
IF you source a script the environment variables persist. A sourced script should not call exit or you will be logged out.

Two ways to source a script named env.sh
Code:
. env.sh
source env.sh

Those tools probably had you running inside a child process, with the parent process killed off. So when you exit the now-current child process, you log out.

Another more sensible approach: In C/perl you can all exec to run a command like "bash -c env.sh" to set variables. Which is probably what the perl code did. This does not create a child it replaces the old process. This is also what sourcing does.

Last edited by jim mcnamara; 04-26-2012 at 08:45 PM..
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ENV(1)							    BSD General Commands Manual 						    ENV(1)

NAME
env -- set and print environment SYNOPSIS
env [-i] [name=value ...] [utility [argument ...]] DESCRIPTION
env executes utility after modifying the environment as specified on the command line. The option name=value specifies an environmental variable, name, with a value of value. The option '-i' causes env to completely ignore the environment it inherits. If no utility is specified, env prints out the names and values of the variables in the environment, with one name=value pair per line. EXIT STATUS
env exits with one of the following values: 0 utility was invoked and completed successfully. In this case the exit code is returned by the utility itself, not env. If no util- ity was specified, then env completed successfully and returned the exit code itself. 1 An invalid command line option was passed to env. 1-125 utility was invoked, but failed in some way; see its manual page for more information. In this case the exit code is returned by the utility itself, not env. 126 utility was found, but could not be invoked. 127 utility could not be found. COMPATIBILITY
The historic - option has been deprecated but is still supported in this implementation. SEE ALSO
execvp(3), environ(7) STANDARDS
The env utility conforms to IEEE Std 1003.2-1992 (``POSIX.2''). BUGS
env doesn't handle commands with equal (``='') signs in their names, for obvious reasons. BSD
June 8, 2007 BSD
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