Velocity Reviews - C compiler variants

DanielJohnson said:

> I am a newbie in C programming and I have already heard lot of C
> compiler variants including ANSI, C9X, Borland etc. Could somebody
> complete the list.

ANSI and C9X aren't compilers, for a start.

ANSI is the American National Standards Institute, which standardised C
in 1989. For short, we call that C Standard "C89", but it's a standard,
not a compiler. ISO (the International Standards Organisation) adopted
that standard the following year, which is why we also refer to "C90".
"C9X" was the great upgrade-to-C project which finally resulted in a
modification to the Standard (the X was used because they didn't know
when they'd finish). This has become known as C99, since it was
eventually released in 1999. (There was a minor update in 1995 too,
which some people ignore and others know as C95.)

To list all the C compilers is a task beyond my ability to answer, but
the principal serious contenders are gcc in its many flavours,
Microsoft C, and Borland C. C/370 and perhaps LE370 for the mainframe
market, Norcroft for embedded systems. Dozens more, though.

All these compilers (as far as I know, anyway) conform to the ANSI C
Standard of 1989 - and *therefore* the ISO C Standard of 1990 (since
it's the same document, just with different section numbering because
ISO added a few lumps of boilerplate to the beginning).

None of them, as far as I know, conform to C99. There are one or two
conforming C99 compilers out there, but nobody I know actually uses
one. C99 conformance is not high on the implementation agenda, and is
unlikely to become so.

> Which compiler is the most versatile and largely used ? I am using gcc
> on Ubuntu as I don't have access to any other ones.

gcc is fine.

> Can sombody throw light on how the journey of C has changed from K&R
> times to now.

See above for a quick precis, or take a peek at
http://www.cs.bell-labs.com/who/dmr/ for some background on C.

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at the above domain, - www.