Re: The correct way to use "for" without polluting the environment

[Alan Wild]

I'm really curious to see if anyone else offers better ideas, but the ways I've done this are

1) exactly what you propose.  

2) use a subshell (parantheses):

$ ( for x in a b c; { echo $x; } )

a

b

c

$ typeset -p x

bash: typeset: x: not found

3) use a function and declare x local to the function

$ function f() { local x; for x; { echo "$x"; }; }

$ f a b c

a

b

c

$ typeset -p x 

bash: typeset: x: not found

-Alan

On Sat, Mar 7, 2015 at 4:31 PM, Peng Yu <pengyu.ut@gmail.com> wrote:

Hi, I use unset to remove x from the environment once the for loop is
finished. Is it the best way to do in bash? Thanks.

for x in a b c
do
  echo "$x"
done
unset x

--
Regards,
Peng

--

alan@madllama.net http://humbleville.blogspot.com