I'm trying to write a simple, console based application in linux, in c++. I know how to start in Eclipse and I have some experience in c++ from Windoze. I would like to ask, if there is some tutorial available on writing console apps. I mean, I know from using linux that there are two conventions on using parameters in command line (-v and --version for example).
View 2 RepliesI'm currently doing a tutorial for writing kernel modules. Right now I'm still at the very beginning, i.e. writing my helloworld stuff.
But what I like to do now is to write stuff onto the console, and I don't get it. According to my tutorials I can print stuff on the console using the printk()-function as long as the priority-level of the macro used in printk() is lower than the console_loglevel (how can I find that value out btw?).
But it doesn't work for me. Even if I use KERN_EMERG it still gets only logged, but not printed on the console and I thought KERN_EMERG get always printed...
Here's my code:
Code:
Code:
Everything works fine. But as soon as there are any blanks in mystring, e.g.
Code:
I always get
Code:
Why do I get this error and how can I insert string with blanks?
I want to write an application with an interface similar to those used in non-GUI linux installation programs. It is not really a pseudo-graphic. Does anybody knows an appropriate library?
View 2 Replies View RelatedHow system call internals could be known ? I mean for example if i take the example of write system call of linux kernel, where i can find out the code of write() system call in the kernel source tree ? The problem is write() system call directly write on console.If we want to write the data on some web page then write() system call will not do that ? How to redirect out data from console to application like html/web page?
View 6 Replies View RelatedI want to be able to access my email account from the console. I'm reading all day about fetchmail, postfix, sendmail etc. but all the stuff I found is related to building whole mail system. All I want to do is to read my emails and write some. Which is the painless way to do this? I successfully configured Evolution for this purpose but I want to do that from the console.
View 10 Replies View Relatedwhen I use LOG action in some chane of iptables rules, I get the output both in STDOUT or STDERR of the xm console and in /var/log/messages.
Is there way to make iptables to write only to log without writing to console?
I try to understand the way the network-admin tool retrieve and set information about the network connections, and after reviewing thee code, I still dont undertsnad how it does it. I thought that it should use maybe linux commands such as iwconfig or ifconfig or by using ioctl for get/set the parameters of the wireless, but I did not find such things in the code. It also does not use AT commands for modem devices parameters.
I see that it uses liboobs files, but after veiwing the code, I still don't understand how it works.
These question comes since I work on application which connects to wireless devices (possibly several wifi and modems devices can be connected ), and I try to think how to set/get the network parameters, I thought that a good start will be to look at how network-admin works.
I tried this command to print the buffer of an existing screen session to stdout but I don't know why it doesn't print anything.
screen -x lftp -X hardcopy /dev/fd/1
screen -x lftp -X hardcopy /dev/stdout
It works if I use a regular file instead, so why doesn't it print to stdout when I use /dev/fd/1? I do this with other applications don't have an option to write to stdout and it works, so what does GNU/Screen do that makes it not work?
I am writing a script that is designed to verify an application is running. The if...else statement in question is the following:
Code:
# Check if <application> is running.
ps -ef |grep <application> > /dev/null
RC=$?
echo $RC
[Code]....
I have started testing by disabling the application in question, and then running the script. The problem that I am seeing is that even though the application is not running, I am getting an output code of 0 due to the successful running of the ps command. What syntax change(s) do I need to make in order to accurately determine when the application is not running?
I tried to use NDN [URL] which is fork of famous DN . It's more advanced then Midnight Commander and I would like to use it to better understand Debian FS and do console works there. However, I have a problem and it seems that their support forum does not work, so I thought to ask for general help here, in case it's something that can be set in Debian. Problem is that when I run this manager I can't use arrow keys or 'num pad' or PgUp/PgDn/.... pad but only 'central part' of keyboard - regular keys and Fx buttons. So I was wondering if there could be some problem between terminal emulation and this application that can cause such behaviour which is unacceptable for normal usage, obviously.
View 13 Replies View RelatedFedora 14 xfce
HP Netbook 210
I am looking for a good and practical console application. I use midnight commander a lot, and I find it frustrating every time I press the F10 key it displays the drop menu items using the terminal. On occasions I make invisible the menu bar, by disabling in the view menu.
So I am looking for a good console application that when I use midnight commander if I press the function key buttons it doesn't display the drop down menu options.
I have a need to start an application on bootup on the linux console and I do not have a need for any type of login or security. I do not need any ALT-F1,F2,etc virtual consoles but I would like to allow SSH access via the network port for debugging, loading, etc.
The application is a SDL graphics program running with fbcon as the SDL_VIDEODRIVER if that matters. I'm currently using Fedora 10 and 12 but any distro that supports SDL using the fbcon framebuffer would be acceptable.
I have a platform independent compiler. so, i created the common api's and platform api's using my complier. so i have this library files named cmn_api.a & platform_api.a in my auto/linjtag/lib.(they will be created when we run the makefile of the compiler).
The problem is when i'm trying to run the console application of my compiler. i have a menu.c from which i choose different modes and i operated on that.
When i tried to open one of the executable i'm getting this error:
I am going to write a TCP server program using c. Can anyone give me some advices on whats and what not to do specially when using select?
There would be a lot of data to be transferred both on the server and back to the client. I already have a simple server here but the server uses a lot of resources. Maybe 3 to 4 connections and the server's load would rise to unacceptable levels.
Which do you think is better to use fork or select?
I want to write some PHP for a website that'll have the data that the script will generate written inside a table with thin black line around it, much like LQ itself. My problem is: how do I draw the box that the text will be inside of, since the amount of text will vary - if I have a GIF with a picture of a box, that'll be of a fixed length, and my script can then only generate that much text, for it to look nice. Or do I need to fiddle with the GD library to get done what I want?
View 4 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 written a daemon server. I would like to add the ability for the daemon to update itself. That is, it should be able to download the latest version of the code (when it receives a signal from a client) and then restart itself. I am stuck on getting the daemon to restart itself. The problem is killing the old daemon without killing the process that is starting the new daemon. In my latest attempt, the daemon that is updating itself runs a program in a subshell (using system) that starts a restarter daemon that runs the original daemon (again using system) with the restart command option. With the restart option, the new version of the daemon sends a terminate signal to the old version. Obviously, when I run the original daemon manually with the restart option, it restarts reliably. I figured that issuing the same restart command from a daemon would adequately isolate the process doing the restarting from the program being restarted. Using ps, I can see that the daemon does actually restart. However, the client locks. In fact, a few times, the OS locked and I had to reset.
View 7 Replies View RelatedHow to write a mkdir with -p option. I am struggling for creating subfolders. the chdir() is not working and thus subdirectories can't be created.
Code:
I'm not able to write to a file using my perl cgi script which is as fallows:
Code:
#!/usr/bin/perl -w
use strict;
print "Content-type: text/html
[Code]....
I am trying to write .pgm images using the O_DIRECT flag in open().I have a char* buffer which has the image data. I know that I have to align the buffers and have done that using posix_memalign() yet only a part of the image gets written.Has someone used O_DIRECT for writing files successfully?
View 1 Replies View RelatedMy platform is linux Centos 5. I have read that to learn programming is to read well-written code and take some project to work with. I am always fascinated by routers and firewalls. Like pfsense and vyatta. May be my searching skills are worst but i am not able to find any good tutorials. Ofcourse i dont expect anyone to write a complete router on their blog but wasnt even close to it.
View 1 Replies View RelatedI am running a java application on centos. For now I have a gsm modem connected via the the usb cable. Below is the message I get when I type the command dmesg | grep tty
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
00:0c: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
usb 2-2: pl2303 converter now attached to ttyUSB0
[code]....
Code:
int main ()
{
[code]...
I have assignment to write bash script and I have to submit it after tommorow . I do not have experience to finish it by myself.I am really need help if any one can contact me. on my email I will be thanks him/ her.
View 14 Replies View RelatedReading and writing text files in C?
View 9 Replies View RelatedI would like to write a program that can read every ethernet frame arriving on a specific hardware NIC, without a TCP/IP stack otherwise doing anything on that NIC. Likewise I want to be able to write out to that NIC. So every arriving ethernet frame, of all types, would be readable (probably one at a time to preserve frame boundaries). And every write of exactly that same data would send frames out. The data read and written would be the whole ethernet frame. The kernel would do nothing else with this data, but other NICs would still operate as usual.
What I would be doing is that on 2 separate NICs, copying frames from one to the other, as in bridging. But I would also be doing modifications per what my program needs to do (not at liberty to say what that would be). What facility would I need to be looking at to do this? There is no ethernet device file. Would raw sockets be able to do this? The programming language will be C.
I created a small C++ program which starts a server in a separate thread and waits the user to press q using the standard input/output. Something like:
Code:
printf(...);
server->Start();
[code]....
I am trying to learn how to write a kernel module. I am following the excellent guide from The Linux Documentation Project called The Linux Kernel Module Programming Guide v.2.6.4.
My machine is running Ubuntu Lucid Lynx (10.04)
Code:
I installed the corresponding linux headers and just to make sure I also installed the linux source and extracted it in /usr/src
I am trying to run the following trivial kernel module
Code:
I just want to read and write some values (integer) to my driver. I used put/get user but always getting errors.
driver
Quote:
int Wert;
static int device_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsinged long arg)
int ret;
[code]...
Quote:
int WERT
ret=ioctl(fd, SETIT, WERT)
ret=ioctl(fd, GETIT, WERT)
if i say in C++ WERT is 5 the value arg of the driver becomes 5 but not WERT the returnvalue of get and put user is -1 so it failed.
I want to write data to serial port ( ttyS ) from inside the kernel.
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