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Does inline assigned variable followed by shell built-ins accessible by the subsequent commands?

I am trying to understand how posix shell behave when command is in the form,

# variable assignment followed by a shell built-ins.
var=value shell_builtins;

in scenario like this, posix manual says,

if the command name is a special built-in utility, variable assignments shall affect the current execution environment. source

to me this seems to indicate that variable var will be accessible for all the later command in the same command line session. However,

$var=value pwd
/home/red
$echo ${var}
#prints nothing

what am I missing?

I also tried bash in posix mode with bash --posix. Result is same.

Solution

  • pwd is not a special built-in utility. Special built-in utilities are break, :, continue, ., eval, exec, exit, export, readonly, set, shift, times, trap, and unset. See:

    $ set -o posix
$ unset x
$ x=y shift 0
$ echo $x
y