On Wed, Jun 5, 2024 at 5:24 PM Collin Funk <collin.fu...@gmail.com> wrote: > > Hi, > > Hongyi Zhao <hongyi.z...@gmail.com> writes: > > > Using env command: > > > > env PATH="/custom/path:$PATH" my_command > > > > Directly setting the environment variable: > > > > PATH="/custom/path:$PATH" my_command > [...] > > In what scenarios would it be more appropriate to use env versus > > directly setting the environment variable? Are there specific > > advantages or disadvantages associated with each method? > > One minor problem is that csh [1] doesn't use the same syntax for > variable assignment. Up until recently FreeBSD used csh as the default > login shell for root accounts. I doubt you will run into the problem > anywhere else. > > Here is an example: > > $ bash > $ env | grep '^VAR' > $ env VAR='abc' | grep '^VAR' > VAR=abc > $ VAR='abc' env | grep '^VAR' > VAR=abc > $ csh > % env | grep '^VAR' > % env VAR='abc' | grep '^VAR' > VAR=abc > % VAR='abc' env | grep '^VAR' > VAR=abc: Command not found. > > You could use: > > % setenv VAR 'abc' ; env | grep '^VAR' > > But that would set the environment variable in the parent process which > isn't the intention. > > Collin > > [1] https://en.wikipedia.org/wiki/C_shell
Thank you very much to everyone here for their responses to this issue. I need to carefully read the relevant explanations and further observe in subsequent practices to see if I have fully understood the issue or if there are still areas that need further discussion. Regards, Zhao
