LinuxQuestions.org - set or env?

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- - set or env? (https://www.linuxquestions.org/questions/linux-newbie-8/set-or-env-346244/)

Hi,

The commands set and env both deliver the environment variables and their values, however

Code:

set | wc -l

769

env | wc -l

81

What ist the difference between them?
Could somebody name a good tutorial with examples?

Regards, Carsten

Hi Carsten,

The difference is that 'set' is also reporting shell-local variables. These look the same from the point of view of the shell user, but are not passed on to the new process if you run a command. When you use the 'export' command you promote a shell variable to be an environment variable.

Environment variables are a fundametal feature of Linux, while shell variables are just a feature of the shell. To fully understand how environment variables work you really need to appreciate the fork/exec process model. I would direct you to the mighty Rute for some explanation:

http://www.icon.co.za/~psheer/book/node12.html.gz

TIM

Tim,

Thank you very much for the excellent explanation. And thank you also for the Rute link. I read the Rute book more than 4 years ago, and I completely forgot about it. Great book.

Regards, Carsten