comp.lang.c http://groups-beta.google.com/group/comp.lang.c
Today's most active topics: * What Defins the "C" Language? - 56 new http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/1e1b95d250c4408d * Zero length array declaration - 24 new http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/8a95176b9393b061 * struct named 0 - 14 new http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/b7026c716c8ddf97 * Exception trapping in C? - 12 new http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/23f1ccb11ccf82a3 * Unexpected behaviour of malloc - 11 new http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/dca7a8b05dacd31f Active Topics ------------- struct named 0 - 14 new ----------------------- ... ^^^^^^^^^^^^^^^^^^^ Prove it! In 6.3.2.3 the Standard describes several types of conversions involving pointer types. Just prove that conversion from null pointer constant to a pointer type and conversion from integer type to pointer type are the *same kind of conversions*, and I'm with you. (Whether it happens and compile- or run-time, doesn't matter.) - Thurs, Dec 2 2004 11:26 am 14 messages, 4 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/b7026c716c8ddf97 Learning C with Older books ?. - 7 new -------------------------------------- ...[ ... ] ...Yes, but it's a non-sequiter -- both the original (Ratfor) and second (Pascal) editions of the Software tools book were intended to be portable to many different environments. What makes _The UNIX Programming Environment_ significant is that it was NOT intended to be portable at all. It was intended to target UNIX - Thurs, Dec 2 2004 8:53 am 7 messages, 5 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/66bc74d8d8d22b33 What Defins the "C" Language? - 56 new -------------------------------------- In Harbison and Steele's text (fourth edition, p.111) it is stated, The C language does not specify the range of integers that the integral types will represent, except ot say that type int may not be smaller than short and long may not be smaller than int. They go on to say, Many implementations represent characters in 8 bits, type short in - Thurs, Dec 2 2004 7:41 am 56 messages, 24 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/1e1b95d250c4408d Zero length array declaration - 24 new -------------------------------------- On Thu, 02 Dec 2004 02:38:56 GMT ...He does *not* want the structure to point to a buffer containing the message. The int foo is almost certainly part of the message comming over a communications link followed by a number of bytes. For instance, the bytes recieved might be int 5 byte 1 byte 2 - Thurs, Dec 2 2004 1:54 pm 24 messages, 13 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/8a95176b9393b061 compiler won't allow dimensioned array of Char* to be signed to another??? - 9 new --- On 1 Dec 2004 19:32:13 -0800 ...As long as you are only accessing it for reading! ...The warning doesn't meen you need a cast, it meens the variable is of the wrong type somewhere, either that or the compiler is broken or you are not doine what you show. [EMAIL PROTECTED] ~ $ cat t.c ...int main(int argc, char * argv[]) - Thurs, Dec 2 2004 11:20 am 9 messages, 7 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/639e49c6fe362f Systems software versus applications software definitions - 2 new ----------------------------------------------------------------- On Wed, 1 Dec 2004 16:33:21 +0100, Charlie Gordon ...For numbers expected to be greater than five, it's easier to use a binary method of some kind (I dislike having to use the other hand to keep track of how many fives I've had). Gray code has the advantage that only one bit changes at a time. I learnt it as a teenager (I 'inherited' some optical shaft encoders - Thurs, Dec 2 2004 11:27 am 2 messages, 2 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/3fa8770993ebe026 floating point over-/under-flow - 4 new --------------------------------------- <puts on Compiler Vendor hat> I've recently discovered that [at least two of] our compilers don't make any attempt to handle floating point overflow in add/ subtract/ multiply/divide, with the result that programmers who don't range- check their data can e.g. multiply two very tiny values and end up - Thurs, Dec 2 2004 10:06 pm 4 messages, 4 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/d321a07f0c79dbef support large files - 2 new --------------------------- ...Hi. <snip> ...<snip> The '::' indicates you are using C++. I think you will get a better aswer in comp.lang.c++. It's definately off-topic here. Sorry. - Thurs, Dec 2 2004 4:08 pm 2 messages, 2 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/c4754b918c00ac8d How to understand C FAQ 3.8? - 3 new ------------------------------------ Jack Klein <[EMAIL PROTECTED]> scribbled the following: ...Now that I have read this, I have understood that the original cause for this discussion, the expression *p++, fits into these rules quite well too. Assume an environment with a linear memory model, which defines and supports casting integers into pointer values. (This is for - Thurs, Dec 2 2004 2:57 pm 3 messages, 3 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/605355148cd352ab Unexpected behaviour of malloc - 11 new --------------------------------------- I am using DevC++ 4.0 lately, which uses Mingw port of GCC, on a WinXP. I am surprised to see the malloc behaviour which is not consistent with the documentation. See the program and its output below. ...int main(int argc, char *argv[]) { char *str1; char *str2; str1 = "Hello world"; printf("Length of str1 %d\n", strlen(str1)); - Thurs, Dec 2 2004 8:23 am 11 messages, 10 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/dca7a8b05dacd31f process steering with pipes - 6 new ----------------------------------- ...Unfortunately kbit() (and indeed "anonymous pipes") are not defined by the C programming language, they are Windows related features. A good place to discuss them would be comp.os.ms-windows.programmer.win32. ...Again, the C language doesn't begin to address an issue like this, ask the Windows experts. - Thurs, Dec 2 2004 5:01 pm 6 messages, 4 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/4888095bd15bfd24 How should I create verbose error information description - 7 new ----------------------------------------------------------------- ...Thanks for your input, Dave. Pondering my alternatives here...the thing is that I need to make this thread-safe and that rules out any static variables, I guess. And having the user call free() after each time he/she calls a function, wanting detailed error information seems cumbersome for the user. I guess - Thurs, Dec 2 2004 8:43 pm 7 messages, 4 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/10ae1eaeb85839ed can not find graphics.h - 2 new ------------------------------- graphics.h meant for only TURBO C and its own graphics libraries,,, it wont work where ever the user wants - Thurs, Dec 2 2004 6:05 am 2 messages, 2 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/5a16a7b6099f5c64 Unix C programming for finding file - 7 new ------------------------------------------- ...<snip> ...Which is pretty much how the English language (and any other) came to be. Long before there were any officials to call it technically wrong. - Thurs, Dec 2 2004 5:22 pm 7 messages, 5 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/f656fbf7205c815e How to best parse a CSV data file and do a lookup in C? - 3 new --------------------------------------------------------------- ...I started with the partial standard (csv.txt) written by Robert J. Lynch originally from [link], then scoured the web for example csv files to test against. I noted the holes, and appended this information to that file -- it covers every anomoly I am aware of and and coincides with StarOffice's StarCalc implementation for every file - Thurs, Dec 2 2004 9:53 am 3 messages, 2 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/86a3ddf0724d9630 What is const char * const *p; - 4 new -------------------------------------- ...This is a quality of implementation issue and you won't find many implementors foolishly ignoring it. If the standard allows such conversions, it is because they are the ONLY *reasonably* portable solution to this class of problems. Dan - Thurs, Dec 2 2004 4:11 pm 4 messages, 3 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/20b6af129c4730cd Clunky C cleanup code - 10 new ------------------------------ ...I think you mean: if(final) final[count] = '\0'; - Thurs, Dec 2 2004 8:58 am 10 messages, 5 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/98ef8cb382bd16c2 Standard Read and Write FILE functions to refer to memory - 1 new ----------------------------------------------------------------- ...I like it, Falconer's Corollary! Brian - Thurs, Dec 2 2004 6:38 pm 1 message, 1 author http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/7e9b399435293d65 Why in stdint.h have both least and fast integer types? - 4 new --------------------------------------------------------------- ...It probably makes sense to stick with fast variants for scalars. The typical use for least variants would be in arrays and structures. ...Because it has no advantages over int_least16_t (except that it is shorter to type, and maybe some minor modulo properties) and has a portability disadvantage. - Thurs, Dec 2 2004 2:46 pm 4 messages, 4 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/abc19ced0e9928b2 qsort - 5 new ------------- ...But it is up to the implementation to choose the program. It will clearly choose a program that it can translate and execute. This does not require it to be able to translate and execute successfully any other program. The compiler could be written to recognise this program specifically and just generate code to produce the correct output. Indeed the program could be - Thurs, Dec 2 2004 5:41 pm 5 messages, 4 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/2329e52e47f51f82 help with advice on how to link with Turbo C (IDE) - 2 new ---------------------------------------------------------- Hello, I have got three .C files in my program. And I am including a header file myheader.h which has a few common functions. However the code implementation of the header file is not available with me. I just have the . LIB ( myheader.lib) file. I dont have access to the source code for the include file. Can any one educate me on how to make my - Fri, Dec 3 2004 1:02 am 2 messages, 2 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/bdf1e873b0b569c4 Let ANGLO SAXON BEAR THE COST OF MISUNDERSTANDING - FREE THE HMONG NOW - 1 new ------------------------------------------------------------------------------ LET THE ANGLO-SAXON BEAR THE COST OF CULTURAL MISUNDERSTANDING - FREE THE HMONG NOW Message-ID: <[EMAIL PROTECTED]> Why does every race have to bear the cost of cultural misunderstanding and racism by the anglo-yankee white bastard ? Indians (Natives) paid with their own genocide. - Thurs, Dec 2 2004 3:00 pm 1 message, 1 author http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/a52ff037a7ff6673 What kind of operator is ( ), [ ] ? unary or binary ? - 5 new ------------------------------------------------------------- Can we consider () unary operator when calling a function, in exps eq. f(), ( 1 + 2). But when we call function f( 10 ) it is a binary operator. Even if we pass f( 10, 20) as we are using , operator there one operand will be there for ()? And Unary operators like !, +, -, ~, ... are said to be having - Fri, Dec 3 2004 12:11 am 5 messages, 5 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/b23f69850b98834b Is there a Swap faster than using XOR!!! - 2 new ------------------------------------------------ ...Details of implementation are immaterial. C is not a portable assembler, no matter what imbecile Ada-heads[1] may want you to think. If the compiler isn't capable of generating correct machine code for correct C, ditch it. Richard [1] Not necessarily a pleonasm - Fri, Dec 3 2004 11:58 am 2 messages, 2 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/b4478c278a5ebed4 How do you read source for big programs? - 1 new ------------------------------------------------ I consider myself quite proficient in C and a few other programming languages, but I have never succeeded in understanding a largish program (such as zsh or ncurses) at the source level. Basically, I quickly become disoriented, losing sight of the forest for the trees. What's your approach for understanding a large program at the source - Mon, Nov 29 2004 1:02 pm 1 message, 1 author http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/ac7df4d68086f7cd openlog() and facility parameter - 2 new ---------------------------------------- Can somebody please explain what the facility paramter is in the openlog() system call. void openlog(const char *ident, int logopt, int facility); The solaris man page says this: The facility argument encodes a default facility to be assigned to all messages that do not have an explicit facilty already - Fri, Dec 3 2004 10:00 am 2 messages, 2 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/d604391050e20309 Exception trapping in C? - 12 new --------------------------------- One of the features from other languages that I miss most in C is trappable exceptions. More specifically, I think it's great to be able to demarcate a whole block of code where several exceptions can happen at various points, so that any one of these exceptions can be trapped and handled by the exception- handling code collected - Fri, Dec 3 2004 6:02 pm 12 messages, 9 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/23f1ccb11ccf82a3 reformatting strings and memory issue - 1 new --------------------------------------------- I've shelved the need for this function since I discovered that the database table can accept the geometry column data in the form "SRID=XXXX;GeometryType( coordinatePair1,.....coordinatePairN)" So I was following the syntax of the SQL statement from the PostGIS manual a tad too literally. However everyone's advice did help for - Fri, Dec 3 2004 11:33 am 1 message, 1 author http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/c82e54fafce3fc77 libwww compilation on MSVC 7.0 - 1 new -------------------------------------- I am developing some c/c++ programs to fetch .zip files from various external spatial data providers. I need to build the libwww libary in order to make sure that I can write code to download these files via http and ftp protocols without using Microsoft-specific functionality. (client requirement) According to their site.... - Fri, Dec 3 2004 8:02 am 1 message, 1 author http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/9a1b49847e646330 Using hobby source code in your job ? - 10 new ---------------------------------------------- Ok, Suppose you have programmed a lot of "re-useable" source code. Suppose you're considering taking a programming job in the same language as your hobby programming language. The question rises: 1. Do you use your hobby source code in your job ? This could create problems ?!? 2. For example without thinking about it you might loose the rights to your - Fri, Dec 3 2004 11:47 am 10 messages, 9 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/a60dfe865a7807c4 superfluous ids in self-referential typedef struct - 8 new ---------------------------------------------------------- ...typedef struct node node; struct node { node *next; - Fri, Dec 3 2004 10:52 am 8 messages, 8 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/c16ee945846ea268 extern - 2 new -------------- My question is about extern variables. I have a structure in a .h file and its made extern as follows, extern STATS_STRUCT Status[]; Actually in the .c file, the size of the array is defined. how does it work ? When is the memory actually allocated ? -- shalu ------------------------------------------------- ----------------------- - Fri, Dec 3 2004 1:30 pm 2 messages, 2 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/7189203cd460f8c3 kernel modules - 2 new ---------------------- ...Sorry, but you're really wrong here, Linux kernel modules aren't really something you can do with standard C and the special magic required to compile them is even more off-topic here. Please take this to e.g. comp.os.linux. development.system where it's exactly on-topic. Regards, Jens - Fri, Dec 3 2004 10:56 am 2 messages, 2 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/b4012566bef6190c Best Way to Define/Declare/Initialize Variables Simultaneously? - 4 new ----------------------------------------------------------------------- ... The scheme you're using (or variants of it) is one way. Another is to use a "helper" program to generate both the .c and .h file from a single common source, which can be written in a "little language" designed for the purpose. HOWEVER, neither method will save you much work. Or to put it differently, neither method *ought* to save you much - Fri, Dec 3 2004 11:32 am 4 messages, 4 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/08773c5cba05fe18 ptrdiff_t - 5 new ----------------- I have written a function to copy a substring: char * salsub( char const * const s, char const * const p ) { ptrdiff_t const l = p - s; char * const m = malloc(( size_t )( l + 1 )); if( m ){ strncpy( m, s,( size_t )l ); m[ l ]= 0; } return m; } Now, AFAIK, ISO-C does not guarantee that a difference - Fri, Dec 3 2004 12:50 pm 5 messages, 4 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/f7b68f6aa5cf3a36 equation of cone intersection - 2 new ------------------------------------- Hi, How can I program this math. equation: a1*n1 + a2*n2 + a3*n3 = cos(alpha1) b1*n1 + b2*n2 + b3*n3 = cos(alpha2) n1^2 + n2^2 + n3^2 = 1 The problem is, that when you solve for n1, n2 and n3 (anything else is known) you get really huge results. So is there maybe another way to compute this? - Fri, Dec 3 2004 1:22 pm 2 messages, 2 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/7010f405c64d1f1a IVT at address 0 - 2 new ------------------------ ...Make that "potential problems" -- maybe it works, maybe not. :-) In article <[EMAIL PROTECTED]>, ...We would need to know one other thing about the hardware and/or compiler involved: do pointers have any "special" bits that mark them as valid pointers, for instance. If not -- if we just need - Fri, Dec 3 2004 2:30 pm 2 messages, 1 author http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/544cc5168c075195 #include from a subdirectory - 3 new ------------------------------------ How do I include headers which are in a sub directory (not in my main src dir)? I use a scripting language - Lua - to extend my C app and all the Lua code is in the subdirectory \lua. I want to include the lua.h header in one of my main source files but ...doesn't work... I've just tried it on Windows but the app is supposed to be portable to - Fri, Dec 3 2004 6:15 pm 3 messages, 3 authors http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/883d0ea16d4bc599 char **argv & char *argv[] - 1 new ---------------------------------- (again :)) Hello everyone. I'll ask this even at risk of being accused of not researching adequately. My question (before longer reasoning) is: How does declaring (or defining, whatever) a variable **var make it an array of pointers? I realize that 'char **var' is a pointer to a pointer of type char ( I hope). - Fri, Dec 3 2004 7:51 pm 1 message, 1 author http://groups-beta.google.com/group/comp.lang.c/browse_thread/thread/15bceffce8ac18d6 ============================================================================== You received this message because you are subscribed to the Google Groups "comp.lang.c" group. To post to this group, send email to [EMAIL PROTECTED] or visit http://groups-beta.google.com/group/comp.lang.c To unsubscribe from this group, send email to [EMAIL PROTECTED] To change the way you get mail from this group, visit: http://groups-beta.google.com/group/comp.lang.c/subscribe To report abuse, send email explaining the problem to [EMAIL PROTECTED] ============================================================================== Google Groups: http://groups-beta.google.com
