meaning of DOS command

[suja.somu]

Can anyone explain me the what the below DOS subroutine does?


In Before Job subroutine : EXECDOS

for %I in (D:\APPDATA\VAS\IN\tmcad.txt) do if %~zI==0 (exit 1) else exit 0

[chulett]

It checks the file's size and fails the batch if the size is zero.