you have to read from many devices separate devices and make it look like a single one. It sounds very much like a device driver to me, perhaps... but getting my hands dirty with kernel code sounds like a daunting task for me that I've never done it...
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i would like to implement dhcpctl in a program to manipulate dhcp leases. It doesn't work and there are errors at compilation :
/tmp/ccYPRIt5.o: In function `LeaseCleaning(std::basic_string<char, std::char_traits<char>, std::allocator<char> >)':
pxe.cpp.text+0x133a): undefined reference to `dhcpctl_initialize()'
pxe.cpp.text+0x1352): undefined reference to `dhcpctl_connect(__omapi_object**, char const*, int, __omapi_object*)'
[Code]...
Is there a way to determine the IO size that is being used for reads and writes to an attached storage device? I am trying to pattern the IO sequences to storage. I have seen mentions to max_sectors_kb but the notes indicated that changing this value did not change the IO size to the storage.
View 1 Replies View RelatedI was analyzing the Disk read using hdparm utility. This is what i got as a result.
Code:
# hdparm -t /dev/sda
/dev/sda:
Timing buffered disk reads: 108 MB in 3.04 seconds = 35.51 MB/sec
Code:
# hdparm -T /dev/sda
/dev/sda:
Timing cached reads: 3496 MB in 1.99 seconds = 1756.56 MB/sec I m not sure what does Cache read and buffered disk read mean.
How do you go about getting the raw size of a block device under Linux from within a C program? And I mean the raw size of the block device itself, not a file system that may or may not be installed on it. And I'd like to be able to get the raw size of any block device, from hard drives (e.g., /dev/sda) to LVM partitions (/dev/mapper/vg0-home) to loop devices to anything else that is a Linux block device.
View 3 Replies View RelatedIs there already a program that reads multiple pipes or file descriptors and writes to the standard output (not splitting lines).Like cat, but reading all files simultaneously and preserving lines.It is needed to avoid coding of select/epoll loops or using multithreading in simple programs. Like "select loop for bash".
View 1 Replies View Relatedi am trying learn to program linux kernel modules and smoothly transition in device driver programming. I have a year and a half worth of programming in C and have been using linux for years!! But my question is how do i compile a module? I got as far as coding it but am stuck as of now.
View 2 Replies View Relatedhow to use socket programming in order to implement chatting feature
View 5 Replies View RelatedSo I need to write a bash script that can read lines and column 3 from a file. It needs to start on line 16 and read every 20th line starting from there. But the value that it reads needs to be checked, should it be too great I need it to shut the program down.I'm pretty new to bash, but my ultimate goal is being able to safely run a program on a GPU for an extended period of time with out worrying about it overheating. I have a command that outputs information from the GPU every second, and I can save this to a file. So all I really need is something to read and check that file, I played around a bit with the awk command and can't get it to work within my for loop with dynamic variable.
View 7 Replies View RelatedI have a partially completed interpreter that has first-calss functions and can store scopes in variables. That way it is possible to implement a simple class like this:
Code:
MyClass = func () {
value = 0;
setValue = func (x) value = x;;
[code]....
But what about inheritance, and what if I want to know the type of the object?
I am doing real time programming in C++, under Linux. I have two processes, let me say A and B. A process is being started periodically, every 5ms. B process is being started every 10ms. The process A is doing data processing. The process B is reading that data and displays it. I am confused about how to run periodically processes. The problem is that the period of process A should be as much as it is possible accurate (5ms). For the process B it isn't so important. I have created independent processes, each in one .cpp file, and I am starting them from bash file. Is that OK? I don't have to make child processes in order to have parallel processes?
View 1 Replies View RelatedSo basically, there is a really cool writing system I have been working on. It could be viewed (for simplification purposes) like an encryption method for the Latin script.
Facts about the writing system:
It has a little over 300 symbols.
It is syllable-driven.
It is highly compositional (eg. "c", "ca", "cae", "ca " and "ci." all map to different symbols - and NOT by overlaying elements)
Symbols have medium graphical complexity (comparable to Korean Hangul, or Japanese Hiragana)
Has a rather complex set of diacritics (~10, some of which can go on any symbol)
Has no ligatures
How transliteration occurs:
Sequences of Latin symbols map to certain symbols. Example below:[G][rou][p ][hu][g.]Characters sequences between "[" and "]" map to a single symbol (so it would take only 5 symbols to write "Group hug.").
How I want it to work:
I would like to have a daemon that: Intercepts all text displayed on the screen.
Converts it to my writing system (changes letter sequences with individual Unicode codes)
Leaves unsupported symbols unchanged.
Displays all the text on the screen using my font and characters intertwined with the fonts and characters left unchanged.
For example, if you take the following line of C++ code:for (i = 1; i <= n; i++)
I would like it displayed like this:[fo][r ]([i ]= [1]; [i ]<= [n]; [i]++)
Bold-symbols should be in my Unicode font with special symbols defined for this writing system, and the rest should be in its original font and encoding. Also, I would like this encoding to hold for display-purposes only. The data in the memory should remain unaffected. This also means real-time adjustments: if I open a text editor (say, from the OpenOffice Suite) and I start typing, I would like to see what I type encoded with my writing system, even though the document actually contains Latin letters. This also means that the symbol immediately before the cursor may change as you type.
I have these but not working.
size_t count_words(const std::string& s)
{
std::istringstream is(s);
return distance( std::istream_iterator<std::string>(is),
std::istream_iterator<std::string>());
}
and
std::string s; // word count
unsigned int wordno = 0;
while(getline(myfile, s))
{ ++wordno;
if(s.empty())++ wordno;
else wordno += count_words(s);
std::cout << s << '
';
}
myoutput1<< "Number of words : " << wordno << '
';
myoutput1 << "
Word" <<" " <<" Occurrence" <<endl;
myoutput2<< "Number of words : " << wordno << '
';
myoutput2 << "
Word" <<" " <<" Occurrence" <<endl;
I developed a protocol "it's a modification of OLSR" for wireless networks, it was with JAVA and I try to simulate it on NS2, I used AgentJ, so in the TCL I did any thing like usual;
set val(chan) Channel/WirelessChannel ;# channel type
set val(prop)Propagation/TwoRayGround ;# radio-propagation model
set val(netif) Phy/WirelessPhy ;# network interface type
[code]....
and I didn't specified the protocol because I attached my nodes to the JAVA class responsible for the protocol, but when I run it generates errors, it claims the protocol to use, so I don't know how proceeding.
I implemented a SSL client using openssl on Linux and it's working fine i am getting response from server...
But my problem is I have a separate thread for each request comes form front end and i have to do SSL communication in each thread, for this i have to create a separate SSL Context for each thread and this is taking too much time hence my transaction is getting delayed
My question is can we implement Persistent SSL connection where i will do SSL Handshake only at the time of application startup and use that connection in all the threads....
i need to implement a Set class(like in stl) using a vector.Here is my code that doesnt work corectly:
Code:
#include <iostream>
#include <vector>
template<class T>
class Set
{
[Code]....
How can I implement c_str() for a string class?
View 2 Replies View RelatedI have an interpteter that supports string literals, and the way it works is that the lexer returns the entire string as a single token, with the quotes removed and escape sequences replaced with the literal characters they represent.
I already implemented single-quote strings, they don't interpret any characters specially except for the single quote. I partially implemented double-quoted strings, they already support all the same backslash escape sequences that C does. But I would also want to add variable substitution.
The way it would work is that "${expression}" would interpret the expression (which could just be a variable name) and replace itself with the result. But I have no idea how to do this.
In case it matters, I'm using a hand-written lexer and recursive-descent parser.
I need to implement SAML 1.1 SSO process in Php(Preferred), Java, or C# I am having a very difficult time finding information related to this task. If I could use SAML 2.0 I would be home free with "Simple Saml Php" but I am not that lucky. Would the process be as simple as building the SAML in XML then submitting it with a SoapClient? According to the Docs I've read that would appear to work.
View 1 Replies View Relatedhow to implement inheritance an polymorphism in plain C. Most of them do this through function pointers.However I'd like to support multiple inheritance.
View 14 Replies View RelatedI'd like to implement a dynamic menu which will allow me to specify an IP address and read it into memory. This is what I've got so far (it's fairly basic...)
Code:
IPS=`ifconfig -a | grep 'inet addr:' | awk '{print $2}' | tr -d "addr:"`
PS3='Select an option and press Enter: '
select i in $IPS
do
case $i in
$i) echo $IPS;;
esac
done
echo $IPS
At the moment it just says "Which IP would you like to use" and then freezes, most success I've had is it showing all the IP's listed in ifconfig and then showing the same menu.
I'm implementing a TCP protocol. TCP implementation requires to send packets continuously and if the receiver doesnt respond after a particular interval of time it should resend the packet again. I need some method to implement a timer expiry function. How can I implement it? Should i implement threads (If yes can you please give a sample)? or is there any better method? I'm implementing it in a Unix system.
View 3 Replies View RelatedI wish to implement some part of my codes to use the GPU of my graphic card but I have no idea whether GNU as already implemented it (as for OpenMP). I mean, there are PGI Fortran compiler which embedded CUDA but I figure it's not free. I also wonder if that works only with ATI graphic cards or if for instance I can use my Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller.
View 4 Replies View RelatedI've got a (very) simple perl xinetd server that I'd like to port to C++. implement something similar using system() or popen() without success.
[code]...
I'm writing a user ranking module for a site. This ranking depends on some criterias and it's possible to set or unset any one of these criterias in order to consider them in calculating the user rank or not. And here's the way I've implemented the ranking calculation :
when I set one or more of the criterias to be considered in ranking , for each user in the system I insert one record for each criteria , for example : if I have 2 criterias and both are set and consider that I have two users , I'll have :
Ranking table
--------------
username | criteria | to_be_added | score
--------------------------------------------------
user1 | criteria1 | 1 | 0
[code]....
It means I just set the to_be_added field to 1 for all of them and leave the calculation of score for each criteria for each user to the time the user logins so that to prevent doing all these calculations at once , because there are a huge number of users ... But there is one problem , if I want to show for example the best user (based on the highest score) , the result can't always be true because some users might not logged in at that time and their score might be zero .
I am in deeply need of queue (linear data structure) in shell script. How can I implement this ??
View 2 Replies View RelatedI want to know How to find mountable devices and their device files in Linux.
View 4 Replies View RelatedI'm running archlinux & just recently started having a problem where ALL USB devices will stop responding for a second when a new USB device is plugged in. dmesg doesn't provide any hints.For example, I've got my music on an external HD & it will stop playing for like ~30 seconds if plug in my camera or gamepad...This issue only seemed to start after my home partition was erased & re-created, though I don't see how these two issues could be related.I've been running a custom kernel (2.6.35-rc6) for the past few months, and that hadn't changed to spur this issue. Thinking it may have been something weird with the kernel, I even switched over 2.6.36-rc6-mainline, yet this did not remediate the issue.
View 2 Replies View RelatedI have the above bt dongle and I am unable to get the device to scan for remote devices. The dongle and bluetooth software is recognized and from a system point of view is working. Using Suse 11.3 64bits
[Code]...
When I scan the blue led comes on solid and goes back to blinking afterwords but nothing is found. I did try another adapter and the bluetooth worked. BTW The Bluedevel application is real nice and works much better then the kdebluetooth app,
I am trying to write a script to modify /etc/fstab that will add entries for a number of partitions on different disks.
The only thing that I do not know how to do is to obtain a unique id such as the ones in /dev/disk/by-id/ to address by from a given partition (ie /dev/sdb1). In my fstab I noticed that in installation the system added fstab entries that are unique (in /dev/disk/by-id/)
I could simply do /dev/sdb1 and so on, but I would prefer a unique identifier so that each mount point is tied to a partition on a specific and unique physical drive.
i need this to be script-able if possible, if not I would still like to know.
