Benchmarks used to test a C and C++ allocator?
Please kindly advise on benchmarks used to test a C and C++ allocator? Benchmarks satisfying any of the following aspects are considered: Speed Fragmentation Concurrency Thanks! ...
c
fetch value of ipaddress
i want to get ipaddress of mycomputer in a variable this statement prints ipaddress of my computer but i want to assign it in a varible how can i fetch the value of ipaddress from inet_ntoa(inaddrr(ifr_addr.sa_data)) into an variable ip of char* type . printf("IP Address: %s\n", inet_ntoa(inaddrr(ifr_addr.sa_data))); ...
openssl crypto library - base64 conversion
I'm using openssl BIO objects to convert a binary string into a base64 string. The code is as follows: void ToBase64(std::string & s_in) { BIO * b_s = BIO_new( BIO_s_mem() ); BIO * b64_f = BIO_new( BIO_f_base64() ); b_s = BIO_push( b64_f , b_s); std::cout << "IN::" << s_in.length(); BIO_write(b_s, s_in.c_str(), s_i...
One large file or multiple small files?
I have an application (currently written in Python as we iron out the specifics but eventually it will be written in C) that makes use of individual records stored in plain text files. We can't use a database and new records will need to be manually added regularly. My question is this: would it be faster to have a single file (500k-1Mb...
Alternatives to using stat() to get file type?
Are there any alternatives to stat (which is found on most Unix systems) which can determine the file type? The manpage says that a call to stat is expensive, and I need to call it quite often in my app. ...
DB2 Transaction Logs
How to read Transaction Logs of DB2 in iSeries / AS/400. Is there any C or C++ or Java API Any help is appreciated? ...
Is there any cross-platform threading library in C or C++?
Hello, I'm looking for some easy to use cross-platform threading library written in C or C++. What's your opinion on boost::thread or Pthreads? Does Pthreads run only on POSIX compliant systems? What about the threading support in the Qt library? Thanks for any hints. ...
Warning when using qsort in C
I wrote my comparison function int cmp(const int * a,const int * b) { if (*a==*b) return 0; else if (*a < *b) return -1; else return 1; } and i have my declaration int cmp (const int * value1,const int * value2); and I'm calling qsort in my program like so qsort(currentCases,round,sizeof(int),cmp); when i compil...
How can I temporarily redirect printf output to a c-string?
I'm writing an assignment which involves adding some functionality to PostgreSQL on a Solaris box. As part of the assignment, we need to print some information on the client side (i.e.: using elog.) PostgreSQL already has lots of helper methods which print out the required information, however, the helper methods are packed with hundred...
return an address of a double
i'm having an issue understanding why the following works: void doubleAddr(double* source, double** dest) { *dest = source; } i get a pointer to a double and want to change the double that dest points to: //usage: int main() { double* num; double* dest; doubleAddr(num, &dest); return 0; } thanks in advanc...
SMTP on C: STARTTLS via OpenSSL
Hi all! I am using openssl to build secure smtp connections to gmail.com:25. So I can successfully connect to the server and sends a command STARTTLS (I receive 220 2.0.0 Ready to start TLS). Then execute the following code without disconnecting: SSL_METHOD* method = NULL; SSL_library_init(); SSL_load_error_strings(); method = SSLv23_...
char *p="orkut" vs const char *p="orkut"
char *p="orkut" vs const char *p="orkut" whats the difference btwn these two... EDIT from bjarne stroustrup,3rd edition page 90 void f() { char* p="plato"; p[4]='e' // error: assign to const;result is undefined } this kind of error cannont be general b caught until run time and implementations differ in their enforcement of thi...
Question about variable definitions in functions.
Hi. #include <stdio.h> main() { int a; for(a=1; a<=4 && printf("%d ",a); a++) { int a; static int b=a; printf("%d ",(a++)-b); } getchar(); getchar(); } In this code, the printout is 1 0 2 1 3 2 4 3. I understand why the int a; part works differently than the int a which was defined ou...
Dangling pointers and double free
After some painful experiences, I understand the problem of dangling pointers and double free. I am seeking proper solutions. aStruct has a number of fields including other arrays. aStruct *A=NULL, *B = NULL; A = (aStruct*) calloc(1, sizeof(sStruct)); B = A; free_aStruct(A); ... //bunch of other code in various places. ... free_aStruct...
How do I force 0.0/0.0 to return zero instead of NaN in MIPSPro C compiler?
As the question states, I am using the MIPSPRo C compiler, and I have an operation that will return NaN for some data sets where both the numerator and denom are zero. How do I keep this from happening? ...
Rewriting Live TCP/IP (Layer 4) (i.e. Socket Layer) Streams
I have a simple problem which I'm sure someone here has done before... I want to rewrite Layer 4 TCP/IP streams (Not lower layer individual packets or frames.) Ettercap's etterfilter command lets you perform simple live replacements of Layer 4 TCP/IP streams based on fixed strings or regexes. Example ettercap scripting code: if (ip.p...
API sanity autotest help needed
I am trying to auto-generate Unit Tests for my C code using API sanity autotest. But, the problem is that it is somewhat complex to use, and some tutorials / howto / other resources on how to use it would be really helpful. Have you had any luck with API sanity autotest? Do you think there's a better tool that can be used to auto-gener...
Sort Strings by first letter [C]
I have a program which places structures in a linked list based on the 'name' they have stored in them. To find their place in the list, i need to figure out if the name im inserting is earlier or later in the alphabet then those in the structures beside it. The names are inside the structures, which i have access to. I don't need a fu...
Microsecond (or one ms) time resolution on an embedded device (Linux Kernel)
Hey guys, I have a kernel module I've built that requires at least 1 ms time resolution. I currently use do_gettimeofday() but I'm concerned that this won't work once I move my module to an embedded device. The device has a 180 Mz processor (MIPS) and the default HZ value in the kernel is 100. Thus using jiffies will only give me at bes...
How do I check if my program has data piped into it.
Im writing a program that should read input via stdin, so I have the following contruct. FILE *fp=stdin; But this just hangs if the user hasn't piped anything into the program, how can I check if the user is actually piping data into my program like gunzip -c file.gz |./a.out #should work ./a.out #should exit program with nice msg. ...