Is this possible to call c/c++ application from DB2 stored procedure/trigger? If yes, what would be general steps doing it? Any pointers to web resources on the subject? Thanks! ...
I'm attempting to hook into whatever explorer calls when a file is opened (double-click, context menu open, etc.), however I can't figure out which function that is. Originally, I thought it was ShellExecute, as that does the same thing as far as I can tell, but after hooking into it I learned that it's only used when a new explorer win...
On unix using C, my client is listening on port 68 with superuser mode. After sending DHCP discover message, when I try to receive, it blocks in recvfrom means there is no message received or is it like system has a process (DHCP client) listening on same port 68 which receives the message and thats my process are not able to receive th...
char str[] = "some text"; printf ( "%.*s", strlen(str), str ); ** Of course, their buffers, strings yet to be properly targeted ...
Sorry if this is simple, my C++ is rusty. What is this doing? There is no assignment or function call as far as I can see. This code pattern is repeated many times in some code I inherited. If it matters it's embedded code. *(volatile UINT16 *)&someVar->something; edit: continuing from there, does the following additional code conf...
I have a small snippet of code below that i'm running using PellesC. When the code is executed and i've typed a few characters into the console, i press enter. Can you explain to me why the printf("%ld\n", nc); line doesn't seem to get executed? As no output is written to the console. #include <stdio.h> int main(void) { long nc ...
Which is the most reliable way to check if a character array is empty? char text[50]; if(strlen(text) == 0) {} or if(text[0] == '\0') {} or do i need to do memset(text, 0, sizeof(text)); if(strlen(text) == 0) {} Whats the most efficient way to go about this? ...
I'm using CodeLite on Ubuntu and for some bizzare reason GCC keeps throwing this error whenever I try to compile code with a function that returns a pointer to a struct: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘*’ token Here is an example I wrote up to demonstrate this error: #include <stdio.h> typedef struct ...
Most of the applications I've seen that use TCP, do roughly the following to connect to remote host: get the hostname (or address) from the configuration/user input (textual) either resolve the hostname into address and add the port, or use getaddrinfo() from the above fill in the sockaddr_* structure with one of the remote addresses u...
I want to create a socket for accessing IPv4 packets from data link layer. From unix network programming V1, socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP)) 1)I am implementing a dhcp client, is this the correct way of doing that? (means without accessing data link layer, i cannot receive reply from dhcp server) or is there any other e...
Hi, i need to draw a polygon of "n" sides given 2 points (the center and 1 of his vertex) just that i suck in math. I have been reading a lot and all this is what i have been able to figure it (i dont know if it is correct): Ok, i take the distance between the 2 points (radius) with the theorem of Pythagoras: sqrt(pow(abs(x - xc), 2) +...
Everyone always says to profile your program before performing optimizations but no-one ever describes how to do so. What are your practices for profiling C code? ...
In socket programming in Linux I need to write data in socket but I don't know socket is open or close . how to I know that socket is open and close without read ? printf("befor read%d\n", n); bzero(buffer, MAX_SIZE_BUFFER); n = read(sockfd, buffer, MAX_SIZE_BUFFER - 1); printf("after read%d\n", n); if (n <= 0) { break; } printf("be...
Is the static keyword in C used only for limiting the scope of a variable to a single file? I need to know if I understood this right. Please assume the following 3 files, file1.c int a; file2.c int b; file3.c static int c; Now, if the 3 files are compiled together, then the variables "a" & "b" should have a global scope and ...
I'm trying to evaluate different strategies for case insensitive UTF-8 string comparison. I've read some material from the Unicode consortium, experimented with ICU and tried to come up with various quality-of-implementation alternatives. On multiple occasions I've seen texts differ between Simple Case Mapping and Full Case Mapping, an...
Is there a standard way to name them or is it programmer's call? Thank you. ...
I am storing the arguments passed to main in yacc in a file. Now I want the lex to read its input from this file rather than the terminal. I know I can point yyin to a file like yyin = fopen("fn","r"); but this works only when main is in lex. When I use this yyin declaration in main in yacc, it shows an error so please suggest something...
We are planning to port a big part of our Digital Signal Processing routines from hardware-specific chips to the common desktop CPU architecture like Quad-Core or so. I am trying to estimate the limits of such architecture for a program build with GCC. I am mostly interested in a high SDRAM-CPU bandwidth [Gb/sec] and in a high number of ...
Hi, I'm new to working with bits. I'm trying to work with an existing protocol, which can send three different types of messages. Type 1 is a 16-bit structure: struct digital { unsigned int type:2; unsigned int highlow:1; unsigned int sig1:5; unsigned int :1; unsigned int sig2:7; }; The first two bits (type, in my struct abov...
Like the title says, I want to know what "(int (*)())" in a C-define-function-call means? As example, it looks similar to this: #define Bla(x) (Char *) read((char *(*)()) Blub, (char **) x) or this #define XXX(nx, id) PEM_ASN1_write_bio((int (*)()) id, (char *) nx) Thank you in advance! ...