i'm supposed to make persistent HTTP web server which is non-blocking. so far i have used the select() to accept multiple request from different clients. can anybody tell me how should i code to make web server persistent?? ...
Hello! I'm not able to understand some typecasting syntaxes. For eg. float f=7.0; short s=*(short *)&f; What's happening here short s=*(short *)&f? Looks like we're casting something as a pointer to a short and then initializing s to value stored in the address pointed to by something. Now, this something looks like the address of va...
Hi, I am required to write a function that uses a look up table for ADC values for temperature sensor analog input, and it finds out the temperature given an ADC value by "interpolating" - linear approximation. I have created a function and written some test cases for it, I want to know if there is something which you guys can suggest to...
If i have a int and a size_t variable,can i compare them like: int i=1; size_t y=2; if(i==y) do something.. or i have to type-cast one of them? ...
mmap(NULL, n, PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0); hi... i am trying to figure out the meaning of above code...? ...
When I use chdir() to change the current working directory, why doesn't the getenv("PWD") give the present working directory? Do I need to setenv("PWD",newDir,1) also? void intChangeDir(char *newDir) { if( chdir(newDir)==0 ) { printf("Directory changed. The present working directory is \"%s\" \"%s\"\n",gete...
#include<stdio.h> int main(void) { int a[3] = {1,2,3}; printf("\n\t %u %u %u \t\n",a,&a,&a+1); return 0; } Now i don't get why a and &a return the same value, what is the reasoning and the practical application behind it? Also what is the type of &a and could i also do &(&a) ? ...
In an interview when I ask the recent graduate students that what is the difference between array and linked list, the first answer normally is "In array you have same data types and in the linked list you can have different data types." When I told them to explain they will say that they have just read it somewhere or that they don't kn...
Hi, I've to read program log file and to do that I wanted to use select() and read() #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/select.h> #include <fcntl.h> #include <stdio.h> int main() { int fd = -1; fd_set fds; struct timeval tv; int rc; char buffer[4096]; char * log_path = "/...
After incorporating Ben Voigt's answer into the code, it appears to work Original question: I'm trying to use dup2 to: pass the output of "ls -al" as input to "grep foo", whose output becomes input for "grep bar", which finally outputs to stdout. The final output is (blank), the file "in" is (blank) & the file "out" has the outp...
Why is the memory of a 2d array accessed by two parameters and not just by one (ignoring pointers).Why is it that the memory diagram is in terms of rows and columns and not straight (horizontal),Further more why is it said that 2d array is a array of arrays but i dont get that . ...
O.S stores in which memory area ...
I would like to put a GSList inside a GHashTable, here is how I managed all of this: #include <glib.h> #include <glib/gprintf.h> typedef struct Foo_ { GHashTable * bar; } Foo; Foo * create() { Foo * foo = g_malloc(sizeof(Foo)); foo->bar = g_hash_table_new(NULL, NULL); return foo; } void add_element(Foo * foo, gchar * key, gpo...
How do I use dup2 to perform the following command? ls -al | grep alpha | more ...
I have written a program that handles signal for Floating point exception and I am using Ubuntu 10.4. Here's my source code : #include <stdio.h> #include <stdlib.h> #include <signal.h> #include <setjmp.h> sigjmp_buf mark; void GeneralHandler(int signo) { switch(signo) { case SIGFPE: printf("\nERROR : Inva...
A lot of c/malloc()'s in a for/while/do can consume a lot of time so I am curious if any operating system buffers memory for fast mallocs. I have been pondering if I could speed up malloc's by writing a "greedy" wrapper for malloc. E.g. when I ask for 1MB of memory the initial allocator would allocate 10MB and on the 2nd, 3rd, 4th etc.....
I'd really like to get more into D, but the lack of good library support is really hindering me. Therefore I'd like to create some D bindings for existing C libraries I'd like to use. I've never done any binding, but it doesn't look too difficult either. I'm planning to do this for D2 (not specifically D1, but if it could be for both, e...
In my program I am trying to resize array using malloc function. #include <stdio.h> int main(void) { int list[5],i; int* ptr = &list; for(i = 0; i < 5; i++) list[i] = i; for(i = 0; i < 5; i++) printf("%d\n", list[i]); printf("----------------------------------------\n"); ptr = malloc(10); ...
Hi all I am trying to generate some numbers with the rand() function like below: int main() { int i=0 for(i=0;i<20;i++) { printf("%f\n",rand_md()); } return 0; } float rand_md() { return (float)rand()/(RAND_MAX+1.0); } But when I run gcc rand.c, I get the error like below: rand.c: In function ‘main’: ra...
Hello all, how can i use Regex Expressions in C programming? for example if i want to find a line in a file DAEMONS=(sysklogd network sshd !netfs !crond) then print each daemon in separate line like this sysklogd network sshd !netfs !crond here what i did so far #include <stdio.h> #include <stdlib.h> #include <string.h> #...