I ran into trouble twice today over (maybe) corrupted files.

The trouble was that the errors I was getting from Linux, or better said, bash, didn't really tell me too much.

In both cases there was talk of "unexpected end of file" and "input/output errors".

Are there any diagnostic tools available for situations like these.

In both cases they were tar.gx files, although in the first case, I was farily sure it was going to be messed up inside. However, bash didn't let me get near it, not being able to copy it to another directory even.

In the second case, I was permitted to extract the file, but it stopped half way, and it could well be due to lack of HD space.

Nevertheless, the errors were particularly uninformative. Are there any tools which aid in finding out the exact problem with corrupted files, and maybe saving bits of them?

were these files programs of one sort or another? if so, they might have an md5sum you could check after download to ensure that they are not corrupted. about the errors, if you could copy them verbosley, and paste them into a post, or possibly a text file for referencing then you could google them, or search for answers here, or post them. i'm unaware of any specific tool to diagnose errors, although, there may be one. hope this helps.
good luck.