linux

write system call to file desciptor ZERO

int main ( ) { char C[] = "Hello World"; write(0,C,sizeof(C)); return 0; } In the above program, I am writing to File descriptor ZERO which I suppose by default is STDIN.. Then why I am I getting output at STDOUT? shadyabhi@shadyabhi-desktop:~$ ./a.out Hello Worldshadyabhi@shadyabhi-desktop:~$ ...

Detect a file is closed

Is there a simple way to detect when a file for writing is closed? I have a process that kicks out a new file every 5 seconds. I can not change the code for that process. I am writing another process to analyze the contents of each file immediately when it is created. Is there a simple way to watch a certain directory to see when a f...

Can I use a serial port as TCP/IP interface on Red Hat Linux?

Background We want to run an FTP server on a Red Hat Enterprise OS. The problem is, the machine we have does not have an Ethernet port/interface (please don't ask why; it's just a project requirement). We only have a serial port. Question Is there COTS / open source software that I can use to make serial port "look" like a an Etherne...

Question about Modal Dialog in Gtk application

Hi, In Gtk application, there is 1 main loop which listens for events (e.g. mouse click, keyboard, etc). And when a modal dialog popup, the main loop is blocked until user clicks 'OK' in the dialog, right? (i.e. nothing will happen when user clicks on the main window). Is that correct? My question is how can firefox did its modal dia...

Embedded Linux for total beginner

Hi, I want to learn how to develop in embedded linux. What materials should I need? I don't have the actual embedded device so I plan to use some device emulator for the PC. I want to know how to load the kernel and the filesystem in the device. Many thanks. ...

Sorting Scientific Number With Unix Sort

I tried to sort these number with Unix sort, but it doesn't seem to work: 2e-13 1e-91 2e-13 1e-104 3e-19 9e-99 This is my command: sort -nr file.txt What's the right way to do it? ...

Shell script argument parsing

There are a number of questions about this sort of thing but lets imagine we are targeting a generic Linux system with both getopt and getopts installed (not that we'll use either, but they seem popular) How do I parse both long (--example | --example simple-option) and short argruments (-e | -esimple-example | -e simple-example) ...

Bash command that prints a message on stderr

I want to know if there is a built-in BASH command that prints some text on stderr, just like the echo command that prints text on stdout. I don't want to use temporary io-redirection. I use a built-in command to generate an error on stderr such as ls --asdf (ls: unrecognized option '--asdf') but I want something neater. Edit ---- Actu...

Supressing GUI?

I am trying to run a plugin designed for Vuze using Java. For this I am using a command like this: /home/x/jre1.6.0_14/bin/java -Dazureus.config.path=/home/x/plugin_directory -Dfile.encoding=ANSI_X3.4-1968 -classpath /home/x/P/lib/swtgraphics2d.jar:/home/x/P/lib/Azureus2.jar:/home/x/P/lib/swt.jar org.gudy.azureus2.ui.swt.Main The prob...

find out the number of threads created by a short running program

I have program that runs fast enough. I want to see the number of threads created by the program. ldd test shows use of library pthread. but how to find out number of threads created by the program. I only have command line access to the PC on which the program is run. The platform is linux. ...

gdb : multithreading

Hi, I have a program which uses two threads. I have put the break point in both the threads. While running the program under gdb I want to switch between the threads and make them run. (thread t1 is active and running and thread t2; when paused on the breakpoint. I want to stop T1 running and run the T2). Is there any way that I can sc...

how to deal with a CP-1252 encoded password under linux?

Hi, I have the following problem. I need to create a zip file under linux with a password provided by another party that is encoded with CP-1252. What I have tried is changing the encoding of this password to UTF-8. Then I made a zipfile protected with this utf-8 encoded password. However the file can not be unzipped in windows with the...

How to display the output of command which run in machine Y.and program is written in machine X?

I have two Linux Machine,1st is machine X ,other is machine Y i want to write a java program which will run in machine X..eq test.java ..and when i run that java program it should ask for login credential of machine Y and will execute some command for example ls -l in machine Y automatically after login. and it should display the output ...

How to tell binary from text files in linux

The linux file command does a very good job in recognising file types and gives very fine-grained results. The diff tool is able to tell binary files from text files, producing a different output. Is there a way to tell binary files form text files? All I want is a yes/no answer whether a given file is binary. Because it's difficult to ...

How to pass parameters to a Linux Bash script?

I have a Linux bash script 'myshell'. I want it to read two dates as parameters, for example: myshell date1 date2. I am a Java programmer, but don't know how to write a script to get this done. The rest of the script is like this: sed "s/$date1/$date2/g" wlacd_stat.xml >tmp.xml mv tmp.xml wlacd_stat.xml ...

How can we get Function name from Spack Pointer(reg/SP) on Linux?

Hi, i am using ptrace to get information related to Callstack on Linux. i can retrieve Spack Pointer to my stack using register returned by ptarces. but using this stack pointer how can i retrieve information related to Function name and signature of current call stack? are there any Linux APIs to traverse this callstack? please help....

Compiling x264 with mp4 support problem

I'm trying to compile x264 with mp4 output support. I download the latest version from their git by typing git clone git://git.videolan.org/x264.git When I run ./configure it configures and I'm able to make it. But when i try to configure it with ./configure --enable-mp4-output and then try to make it, it returns a strange error...

Help with simple linux shell implementation

I am implementing a simple version of a linux shell in c. I have succesfully written the parser, but I am having some trouble forking out the child process. However, I think the problem is due to arrays, pointers and such, because just started C with this project and am not still very knowledgable with them. I am getting a segmentation...

How to know start and kill processes within Java code (or C or Python) on *nix

I need to write a process controller module on Linux that handles tasks, which are each made up of multiple executables. The input to the controller is an XML file that contains the path to each executable and list of command line parameters to be passed to each. I need to implement the following functionality: Start each executable as...

Remove files from Bazaar

I'm using Bazaar (bzr) to keep source code for a website updated, but we've ran into a problem when we remove files from version control. The files we are removing are ones we never intended to version to begin with. When this happens we use bzr rm --keep to remove the file from version control, but keep the file in the file system. Doi...