I'll answer this from the standpoint of what BibDesk is supposed to do, since it was mentioned specifically in the original question.
Here is the content of the example.bib
file I'll be using for this demonstration:
@comment{Here is a comment}
As far as BibTeX is concerned, this is also a comment.
article{test1,
title = "This is missing the opening token, so will be a comment",
year = 2014,
author = "Weiser, Bud",
journal = "Irreproducible Results"
}
@article{test2,
title = "This is a legitimate entry",
year = 2014,
author = "Weiser, Bud",
journal = "Irreproducible Results"
}
@article{,
title = "This is a broken entry",
year = 2014,
author = "Loon, Some",
journal = "Irreproducible Results"
}
@article{test3,
title = {This is another legitimate entry},
year = {2014},
month = sep,
author = {Ann Author},
journal = {Irr. Res. J.}
}
Syntax Problems
If I open this file in BibDesk, it brings up an alert with three options.
- Edit File
- Keep Going
- Give Up
Edit File
If you choose "Edit File", it will open a text editor with your file contents (not shown; in the graphic, I'm using TextMate). Double-clicking a row in the list of warnings and errors will take you to the offending row, where you can edit and then try again.
Keep Going
If you choose "Keep Going", it will proceed to the next error, or open the file in the usual manner (you'll see a list of references). This basically ignores syntax errors, when possible. I don't recall if all errors are ignorable.
Give Up
The final option is self-explanatory. This is where you bail out and fix the problems yourself in a text editor.

Encoding Problems
Encoding problems are separate from syntax issues, but commonly confused. To set a specific encoding to be used, choose "Open File…" from BibDesk's File menu, and set the appropriate encoding. If you don't know what it is, it's safe to choose ASCII, as you'll get an error if non-ASCII characters are encountered. It does not try to guess encoding! If you want to open the file anyway and risk data corruption, use a gapless encoding such as Mac OS Roman, or one of the common Windows encodings.
RIS
RIS data should be treated as comments/junk, unless it contains an @
character; in that case, you're going to see hard-to-decipher errors, and the line numbers may not be all that helpful. In general, though, mixing RIS data in with BibTeX is a really bad idea, even if bibtex
allows it.
Dangers
A program that does exactly as requested by the OP will by definition lose data, and most responsible programmers try really hard to avoid this. Failing with syntax errors is a feature, and one that keeps you from losing your tediously-entered, hard-to-find data!
JabRef
?