create a large buffer in my program so that I can send, and then receive on another pc, more than 4096 bytes (this seems to be the default for the serial port). I thought this might work:
[code]...
im trying to send pages of 4096 bytes from kernel layer of server to kernel layer of client over a network. previously i tried the foll. code , for data less than a 100 bytes it worked fine , but for something larger than that the computer hangs......(even the dmesg's wont say why) i also wanted to know how we could use the 'sendpage' function to solve this problem.
Code:
CLIENT'S KERNEL MODULE
struct iovec iov;
char buf[1024];
[code].....
I'm going to replace damaged HDDs in my server with new drives, which have sector size of 4096 bytes instead of 512. Does CentOS natively support such drives? If yes, since which version? If no, what actions should I take to correctly prepare such a drive to work. How to check that such a drive is correctly recognized by OS?
View 3 Replies View RelatedI am getting a new 4kb sector HDD for my laptop, WD scorpio black 750gb, I would like to image existing partitions on 512bytes sector HDD and move them to the new 4kb sector HDD, what's the best way to do this.
present config is as follows:
Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders, total 156301488 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
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I am planning to keep the same three partitions as the primary partitions on the new drive and add few more logical partitions. I would have liked to move to GPT but since I need Win 7, I am stuck with MBR partiotion table.
Now, I understand how to partition an Advanced format disk, what I want to know is how to move the existing partitions on the 80 Gb disk to the new disk?
I use Clonezilla to copy partitions but it is not compatible unless both the target and the source disks are already using 4096 sector size.
I can use Acronis True Image WD Edition to clone Win 7 but how do I clone Ubuntu?
Also my Laptop's chipset is limited to SATA 1.5, will it cause any issues, I know the bandwidth is not an issue.
I am created one udp socket. i want to send the data(bytes) to another PC.i need to send 614400 bytes of data. while sending it saying error like" message is too long ". so what is the maximum possible data can i send from a socket?
View 3 Replies View RelatedI`ve just installed opensuse 11.4 and i dont know how to write and compile my programs
is there a compiler like turbo c++ to use??
I recently had to move to a new machine, everything went well except for one thing. I did fresh installation of LAMP server all with default configs. Every time I'm using PHP script to that invokes include, require or require_once I get the following error:
Code: Fatal error: Allowed memory size of 20971520 bytes exhausted (tried to allocate 7680 bytes) in /var/www/index.php on line 2 index.php file: PHP Code:
<?php include "index.php";?>
icukapi.php file:
PHP Code:
<?php echo "test";?>
My memory_limit in php.ini is set to 20M. I tried to increase that however it didn't quite work. PHP seems to allocate all possible space and return that message every time i try. If somebody has an idea of how to fix it I would be more than grateful. I spend quite a long time searching for an answer however the all things i found suggested increating memory_limit which in this case doesn't work.
Since 2005 when DualCore CPUs came out, you need to create unique multithread algorithms for every particular program? Or you have patterns?
View 4 Replies View RelatedI am trying to create a screen capture program with Xvfb server, ImageMagick and Khtml2PNG. I seem to be having some issues and was hoping someone could help me out. I have everything installed and working on a centos WHM/CPanel system and am able to generate the screen shots and save them to root folder from shell with the following commands.
Xvfb :2 -screen 0 1024x768x24&
export DISPLAY=localhost:2.0
khtml2png2 --sw 200 --sh 150 http://www.example.com example.png
It works 100% fine when you run it from shell.
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I need to send large files from a Linux machine to another using cryptography. The sender machine knows the recipient IP but not vice-versa. I don't need strong cryptography and prefer higher-speed less-secure solutions.
There are no problems with presharing crypto keys but I'd prefer not dealing with SSH users creation.
I think to HTTP PUT over TLS, but I never had experience with it and I prefer to hear which are the possible solutions. I know that it can listen as a daemon but I don't know anything about cryptography. So pipeing with OpenSSL may be a solution.
I am currently working to develop a perl script for irssi that will capture data from irc channel hold it in memory as variable and send it to a shell. Does anyone know a good irssi irc scripting guide? something that will include $botname, $msg, $nick, $channel etc scripting explanation. Is it possible to send a run program command to shell thats located in my /home/user/myapp using ./myapp from irssi? i am using bash. I've only just started, so i dont have any code written yet,
View 2 Replies View RelatedI have a 58 mg PDF that needs to be sent to a person with Windows. I do not know what special software they have. I only know that I nust send them the file in a way that they can use it. I tried yousendit.com and it tells me I need to install their "yousendit express package". But apperantly it will not run on Linux.
View 9 Replies View RelatedI'm trying to create a separate thread for my program which basically polls using the read command. However this new thread seems to block the main thread, anyone know why this could happen.
In main I call this function pthread_create(&mainEventThread, NULL, GenericEventThread, NULL);
which calls
/*New threads start function */
void *GenericEventThread()
{
short int i, nError = -1;
[Code]...
I've used pthread_self to check that a new thread is being created, so why is the while loop in one thread blocking the main thread from running, I haven't used the join function anywhere in my code.
I am trying to create a RS232 C program that executes a series of commands down the line to a robot. Everything seems to work fine, except any sequential write to the serial port. At first I thought it was the UART's buffer being filled too fast, but even with a 50 uS delay it still throws the error.
Here is my code:
Code:
#include <termios.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/signal.h>
#include <sys/types.h>
[Code]...
How do i fill a file with <n> bytes at a given value ,for example 3?
View 3 Replies View RelatedI am trying to write some code that interfaces with an AVR over a serial port. Basically I send a command then read the output which is 6 bytes. I need to receive all 6 bytes before the program continues. Is there a way to do this? If I use read() it returns -1 unless I add a delay before reading the port. Is there a way to get it to read the 6 bytes as soon as they arrive?In python you simply say how many bytes you want and the max time you are willing to wait which seems a whole lot easier than read
View 1 Replies View RelatedI have a vector of octets that needs to be converted to a std string. I'm currently doing it this way:
Code:
stringstream ss;
for (unsigned int i=0; i < data.size(); i++
{
ss << data[i];
}
string s_data = ss.str();
This works, but is there any better way to do it?
basically i have to create a simple program with will continually read input from the user until they enter a blank linei know how to read in certain input but not sure how to get it continually in a loop
View 2 Replies View RelatedI am trying to resume an aborted download. I have to use the curl_easy_setopt(hnd, CURLOPT_RESUME_FROM_LARGE,(curl_off_t)no. of bytes to be skipped) to set from where to start resuming download. But in run time, how would i put the no. of bytes to be skipped? Its not possible always to see how much is the size of file downloaded already. So is there any way so that prograjm will automatically know from where to start??
View 5 Replies View RelatedWe have a program that catalogs to 40 different mount points. The program is fine as long as thier is free space on at least one of the 40 mount points. My boss wants me to come up with a script that will email us daily to know how much overall free space is left. I know I can do a df but I don't know how to combine the 40 mount points into a single disk used/disk free report.
The 40 mount points are /dev/mapper/areaxx, xx being 01 to 40.
Can httpmethod of httpclient support downloading more than 8192 bytes?
If not, any other ways?
Code:
char retBuffer[100];
recv(sock , retBuffer ,sizeof(retBuffer) , 0);
if i send a string smaller then my buffer size retBuffer always have garbage of the end of it....what can i do to eliminate tis problem ?
Greetings EveryOne
how to check if buffer is empty in c?
writing a code in C program for debugging error and sendingror messagein routingprotocols. please answer with code
View 2 Replies View RelatedI wanna capture network packets from DMA ring buffer, just like netfilter. i wanna capture it from DMA, because i wanna get MAC address of I/O packets, so netfilter not included MAC address of out going packets because its on IP level and Ebtables is like that too. how i can capture network packets from DMA ring buffer.
View 9 Replies View RelatedI add new syscall, and it need copy big data into the buffer specified in user mode. How can i do it? use copy_to_user? or can i use memcpy directly? If i use copy_to_use, is it low efficient?v
View 2 Replies View RelatedI have recently dropped to a command line to run a DB server. In attempting to write a bit of Python to do this process I went to install emacs using apt-get and noticed that the foot print of the install was going to be around 130 Mb. Likewise with a couple other programs the install size was going to be a lot larger than I anticipated. I was wondering how the footprint could be so large and is there a way to install software without this blow out. While I am happy to use vi or import the code from a desktop with a GUI I think this would be interesting to know.
View 2 Replies View RelatedJust purchased a webcam and it worked immediatelly with kopete. This was in the configuration dialog, a small window showed me moving around in all my gloriousness. Now realise why those horror films show this sort of footage.
Thing is: how to make the image bigger, fill the screen? Is there a program? Don't say rtfm, I don't know enough to do that.
I have been developing some code which I have been testing an another i386 system. However I have been getting some weird data received on a socket I am communicating with some 3rd party hardware, I have opened a socket to read data on the hardware's telnet port. The data being read is as expected and my code appears to function correctly.
However I have now began testing the code on a target platform, this platform is of a better spec than my development system. When I read data from the socket using recv(), all the expected data has not been read.A chunk of data from the beginning is missing and a portion of data that would be at the end is now at the beginning of the buffer. I'll try and illustrate this below.
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The algorithm for reading and writing disk blocks use the algorithm getblk to allocate buffers from the pool. In the algorithm getblk, if the kernel removes a buffer from the free list, it must raise the processor priority level to block out interrupts before checking the free list. Why ?Where can i find the C implementation of the above algorithm for buffer allocation in the linux source code ?
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