auto-reload html file with a browser via terminal command

You can use AppleScript to reload the tab. See the Benjie's answer for this question
Use osascript to call the AppleScript from shell script. You'll get something like this:

osascript -e 'tell application "Google Chrome" to tell the active tab of its first window to reload'

Alternatively you can use something like next to close all previous tabs:

tell application "Google Chrome"
    set windowList to every tab of every window whose URL starts with "http://stackoverflow.com"
    repeat with tabList in windowList
        repeat with thisTab in tabList
            close thisTab
        end repeat
    end repeat
end tell

If there is already a tab for foo.html, open foo.html should focus that tab in Safari. For Chrome, you might use something like this:

set u to "http://t.co/"
tell application "Google Chrome"
    repeat with w in windows
        set i to 0
        repeat with t in tabs of w
            set i to i + 1
            if URL of t is u then
                set active tab index of w to i
                set index of w to 1
                tell t to reload
                activate
                return
            end if
        end repeat
    end repeat
    open location u
    activate
end tell

I have just assigned ⌘R to open "$TM_FILEPATH" -a Safari in the text.html scope in TextMate. I have also enabled saving documents when switching to another application, so it basically does the last three steps of the edit-save-switch application-refresh cycle.

Other options:

• http://livereload.com
• http://brettterpstra.com/2011/03/07/watch-for-file-changes-and-refresh-your-browser-automatically