echo $TEST # Test has no value, hence the blank line.
$ TEST=noexport # Set but not exported
$ echo $TEST
noexport
$ env|grep TEST # Nothing found, no output.
$ export TEST # Export it.
$ env|grep TEST # And now it's found in the environment.
TEST=noexport
$ TEST=second # Change its value.
$ env|grep TEST # Same search as above, but the value is changed.
TEST=second
Perhaps the easiest way to look at it is to think of exporting as making a type of global variable. Everyone (within certain limits; for the shell, only its children...) will see the exported variable. If the value changes, it changes "everywhere". I've quoted everywhere because this only applies to children invoked after the change. So if TEST=second and you run an xterm, the new shell sees TEST=second. Change TEST=third in the first shell, you still have TEST=second in the second shell, since it already got its value for TEST. Start a third shell from the first, it will see TEST=third. And so on.
Fred Ma wrote:
Hello, I'm using cygwin bash 2.05b-8 (it's actually gnu). I thought that $HOSTNAME was an environment variable. When I run gnu make (I'm pretty sure this is not a make problem), $(HOSTNAME) is empty. It gets fixed if I do "export HOSTNAME" before running make.Is there a way to check if the export command has been applied to $HOSTNAME? Does the actual transcription of $HOSTNAME's value to the environment happen only once, when "export" is applied, or is there a continual monitoring an mirroring of changes to $HOSTNAME forever after applying "export"? Fred -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Bug reporting: http://cygwin.com/bugs.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
-- Bob McGowan Staff Development Engineer VERITAS Software [EMAIL PROTECTED] -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Bug reporting: http://cygwin.com/bugs.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
