Question

In the bash manual section 3.7.4, it states

The environment for any simple command or function may be augmented
temporarily by prefixing it with parameter assignments, as described
in Shell Parameters [section 3.4].

And a trivial example of this is

MYVAR=MYVALUE mycommand

I have read section 3.4 and I still can’t figure out how to specify multiple parameter assignments. Note that the statement in 3.7.4 is definitely plural, implying that it is possible.

The following does not seem to work:

MYVAR1=abc MYVAR2=xyz mycommand

I am using bash version 4.1, 23 December 2009.

Answer 1

Oops, my example was over-simplified. This works fine:

mycommand () { echo MYVAR1=[$MYVAR1]; echo MYVAR2=[$MYVAR2]; }
MYVAR1=abc MYVAR2=xyz mycommand

but this does not:

mycommand () { echo MYVAR1=[$MYVAR1]; echo MYVAR2=[$MYVAR2]; }
MYVAR1=abc MYVAR2=xyz for f in ~/*.txt; do mycommand; done

and the key difference is this phrase:

for any simple command or function

A for command is a complex command, not “a simple command or function”, according to section 3.2.