Stateful Scripts in Automator?
The following example works for me in a Run Shell Script action in Automator:

f="/Volumes/Canvio1TB/EyeTV Archive/sync.ffs_lock"

if [ -f "$f" ]; then
    echo "$f exists."
else
    echo "$f does not exist."
fi


Note: Shell is set to: /bin/bash

This also works:

f="/Volumes/Canvio1TB/EyeTV Archive/sync.ffs_lock"

[ -f "$f" ] &amp;&amp; echo "$f exists." || echo "$f does not exist."


Here it is in AppleScript in a Run AppleScript action:

set f to "/Volumes/Canvio1TB/EyeTV Archive/sync.ffs_lock"

tell application "System Events"
    if exists file f then
        return f &amp; " file exists." as string
    else
        return f &amp; " file does not exist." as string
    end if
end tell