Well, if you "deleted" in a graphical-way (ie, right-click, delete) I suggest looking in the trash.
If you actually did a rm on it, I'd shutdown the system and refrain from using it until you completely declare that the recovery was (un)successful.
I would also use extundelete if you're using an EXTended filesystem. Moreover, I would do it on a live session.
I know little about linux and was hoping that deleted files in linux were renamed (*.*_) like in dos and windows so I could do a search for (*.*_) and change (_) back to it's original (*) and restore it back.
Story> I rooted my android phone to delete the factory sprint crap, which worked, but accidentally deleted a file that the txt app needs. I can receive txt's and view them, but it freezes a couple of seconds later and tells me that the app failed and I can't send any txt's.
I have tried to update the app with no avail and think it is one of the base files.
After one annoying google search, It seems that Android was using YAFFS2 up until 2.3, and ext4 from then on.
First, I would Plug the phone into the computer without auto mounting, and copy the entire internal storage chip with dd (ie. `dd if=/dev/androidsdx1 of=/android.phonename.yyyy.mm.dd.fstype.img'), and perform ext/yaffs file recovery with a copy of the image (dd even copies the unused space). And if all goes well, you can copy the file(s) manually, or perform the recovery on the phone itself (I would do the former with `cp -prv').
If that fails, I would see if the appstore has the same texting app, and reinstall it.
And if that fails and you do mind about lost data (reflashing the phone (of course, you made an image, so you could theoretically restore the data)), I would copy the file(s) from a friend's rooted phone.
And if all else fails, I would just reflash the phone completely.