Anyone know a good newsgroup for Linux

D

Dawn Minnis

Hi

I know you're not supposed to post OS specific questions on the newsgroup so
does anyone know a good newsgroup - where there are actually people talking
to eachother and not full of spam - where I can get advice on developing C
for a command line driven interface in Linux?

Any advice greatly appreciated.

Kind regards
Dawn
 
L

Lew Pitcher

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Dawn said:
Hi

I know you're not supposed to post OS specific questions on the newsgroup so
does anyone know a good newsgroup - where there are actually people talking
to eachother and not full of spam - where I can get advice on developing C
for a command line driven interface in Linux?

Try comp.os.linux.development.apps
or comp.os.linux.development.system
or comp.os.linux.misc
or comp.os.linux.questions

- --
Lew Pitcher
IT Specialist, Enterprise Data Systems,
Enterprise Technology Solutions, TD Bank Financial Group

(Opinions expressed are my own, not my employers')
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9U+1gVDifG5UvlyYcVD34LA=
=Yl/n
-----END PGP SIGNATURE-----
 
J

Jens.Toerring

Dawn Minnis said:
I know you're not supposed to post OS specific questions on the newsgroup so
does anyone know a good newsgroup - where there are actually people talking
to eachother and not full of spam - where I can get advice on developing C
for a command line driven interface in Linux?

Try comp.os.linux.development.apps, that would seem to be the best fit.
If you want a wider scope also have a look at comp.unix.programmer.

Regards, Jens
 
C

Chris Croughton

I know you're not supposed to post OS specific questions on the newsgroup so
does anyone know a good newsgroup - where there are actually people talking
to eachother and not full of spam - where I can get advice on developing C
for a command line driven interface in Linux?

Since from your email address you're in the UK, you could look at
< While a lot of the discussion there is about
non-programming stuff (installing, using etc.) there are a number of
knowledgable Linux programmers there and it is relatively low-traffic
(compared to comp.lang.c for instance).

(Non-UK people could also look at that newsgroup, but it is less likely
to be on non-UK servers, I know that it is on the BTInternet one...)

Chris C
 
J

James McIninch

<posted & mailed>

comp.os.linux.development.apps
comp.os.linux.development.system
comp.os.linux.misc
 
C

CBFalconer

Dawn said:
I know you're not supposed to post OS specific questions on the
newsgroup so does anyone know a good newsgroup - where there are
actually people talking to eachother and not full of spam - where
I can get advice on developing C for a command line driven
interface in Linux?

Any advice greatly appreciated.

If you were using Netscape I could give you specific instructions
on how to search for a newsgroup that your ISP carries. I suggest
you get rid of Outhouse Excess as soon as possible. It does some
evil things (but not as evil as google groups !!). Mozilla or
Thunderbird would be suitable, from mozilla.org (and free).

As long as you stick to portable standard C you can ask away here.
Very little, if anything, in most programs needs to be system
specific. If you get in the habit of using standard C you will
rarely have porting problems.
 
C

CBFalconer

*** top-posting fixed ***

Dawn said:
Thanks for that

I will try them out.

Please also quickly get out of the Outhouse Excess encouraged habit
of top-posting. Your answer belongs after, or possibly intermixed
with, the material you are quoting, after suitable snipping of
non-germane material.
 
C

CBFalconer

Chris said:
.... snip ...

Since from your email address you're in the UK, you could look at
< While a lot of the discussion there is
about non-programming stuff (installing, using etc.) there are a
number of knowledgable Linux programmers there and it is relatively
low-traffic (compared to comp.lang.c for instance).

(Non-UK people could also look at that newsgroup, but it is less
likely to be on non-UK servers, I know that it is on the BTInternet
one...)

Out of perversity I looked, and att does carry it (and 600 odd
other in the uk group) here in left-pondia.
 
C

Chris Croughton

Out of perversity I looked, and att does carry it (and 600 odd
other in the uk group) here in left-pondia.

Oh yes, many non-UK servers do carry uk.* newsgroups (some of them, like
the Berlin university public server news.individual.net, carry them on
auto-create), but they are less likely to do so than UK servers in
general, I've had (as UK Usenet Control) a number of queries "Where can
I get uk.<x> newsgroup, my ISP doesn't have it?" from people using
non-UK servers. I usually direct them to the free (for individuals)
server above, or for companies to gradwell.net.

Chris C
 
D

Dawn Minnis

Ok, well any chance someone could give me a quick explanation of what this
single line means?

Based on I, K and lda being integers
#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]

If someone could just explain that one line to me i would be very grateful

The rest of the top of the program looks like this:







/* Subroutine */ int dgemm_(char *transa, char *transb, integer *m, integer
*
n, integer *k, doublereal *alpha, doublereal *a, integer *lda,
doublereal *b, integer *ldb, doublereal *beta, doublereal *c, integer
*ldc)
{


/* System generated locals */
integer a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset, i__1,
i__2,
i__3;

/* Local variables */
static integer info;
static logical nota, notb;
static doublereal temp;
static integer i, j, l, ncola;
extern logical lsame_(char *, char *);
static integer nrowa, nrowb;
extern /* Subroutine */ int xerbla_(char *, integer *);


/*
Parameter adjustments
Function Body */

#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]
#define B(I,J) b[(I)-1 + ((J)-1)* ( *ldb)]
#define C(I,J) c[(I)-1 + ((J)-1)* ( *ldc)]
 
D

David Resnick

Dawn said:
Ok, well any chance someone could give me a quick explanation of what this
single line means?

Based on I, K and lda being integers
#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]

If someone could just explain that one line to me i would be very grateful

The rest of the top of the program looks like this:

It is doing treating an one dimentional array as a 1 based two
dimensional array. In C arrays are 0 based (i.e a[0] is the first
element). They want this array to be one based.

lda is not an integer, it is a pointer to an integer, which presumably
has the number of elements in the row.

e.g. if there are 10 elements in a row

A(1,1) -> a[0]; /* first element in first row */
A(2,1) -> a[1]; / second element in first row */
A(1,2) -> a[10]; /* first element in second row */

-David
 
M

Mark McIntyre

Ok, well any chance someone could give me a quick explanation of what this
single line means?

Based on I, K and lda being integers
#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]

looks to me like an extract from Numerical Recipes in C, trying to use a
C-style one-dimensional array "a" as if it were a fortran-style 1-based
2-dimensional array "A". I and J are the row/column indices, and Ida is the
row width. They subtract one because they can't concieve of arrays starting
from zero.

Throw away that book, and buy the new edition, which was rewritten by
people who actually programmed in C.
 
C

CBFalconer

Dawn said:
Ok, well any chance someone could give me a quick explanation of
what this single line means?

Based on I, K and lda being integers
#define A(I,J) a[(I)-1 + ((J)-1)* ( *lda)]

If lda is an integer it will generate syntax errors. lda needs to
be a pointer to an integer. It looks like it is trying to map a 1
based indexing scheme into Cs zero based indexing. It will blow up
badly for I or J values of zero.
 
D

Dawn Minnis

Thanks guys.

Its a line from the resulting C file after putting dgemm.f through the f2c
converter. The result it genuine C code but it looks horrid. But thanks
for explaining that to me. I wasnt aware that you could do that in C.

Regards
Dawn
 
M

Mark McIntyre

Thanks guys.

Its a line from the resulting C file after putting dgemm.f through the f2c
converter. The result it genuine C code but it looks horrid. But thanks
for explaining that to me. I wasnt aware that you could do that in C.

You can, but its dangerous, as it could invoke undefined behaviour for some
values of I and J. Better to understand the algo and write your own C.
 

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