printenv () produces:
boot=
console=*
haltaction=h
testaction=q
systype=0x00020000
getenv ("systype") == 0x00020000
getenv ("crap") == NULL
setenv ("crap", "50"):
printenv () produces:
boot=
console=*
haltaction=h
testaction=q
systype=0x00020000
crap=50
setenv ("haltaction", "cheese"):
printenv () produces:
boot=
console=*
haltaction=cheese
testaction=q
systype=0x00020000
crap=50
unsetenv ("console"):
printenv () produces:
boot=
haltaction=cheese
testaction=q
systype=0x00020000
crap=50
unsetenv ("crap2"):
Variable not found.
printenv () produces:
boot=
haltaction=cheese
testaction=q
systype=0x00020000
crap=50