Finding free space in android mobile from command line

from ur PC's command prompt you can find out the space available in your android mobile. If you have android SDK installed on ur system then you can type following command:
adb shell df
This command will give you total space, available and used space as following:
/dev: 47172K total, 12K used, 47160K available (block size 4096)
/sqlite_stmt_journals: 4096K total, 0K used, 4096K available (block size 4096)
/system: 65536K total, 61216K used, 4320K available (block size 4096)
/data: 65536K total, 32656K used, 32880K available (block size 4096)
/cache: 65536K total, 1156K used, 64380K available (block size 4096)
/sdcard: 522228K total, 1660K used, 520568K available (block size 2048)

If you don't have SDK then directly on ur device terminal you can type "df" and check the space available.
Otherwise there are some tools available as eclipse memory analyzer which will tell you the memory being utilized by programs when they are running, i have'nt used it till now so I don't know much.