linux

gcc architecture question

Hi, I'm compiling my program with architecture set to -mtune=i386 However, I'm also linking statically against several libs (libpng, zlib, jpeglib, vorbisfile, libogg). I've built these libs on my own using configure and make, so I guess these libs were built with architecture being set to my system's architecture which would be i686...

API to translate group name to group id (gid)

File.chown takes an owner ID, a group ID (gid), and a filename. I want to use it to set a file's gid, but what I have is the group name. Is there anything in the standard library that I can use to translate a group name into a gid? ...

What scripts should not be ported from bash to python?

I decided to rewrite all our Bash scripts in Python (there are not so many of them) as my first Python project. The reason for it is that although being quite fluent in Bash I feel it's somewhat archaic language and since our system is in the first stages of its developments I think switching to Python now will be the right thing to do. ...

unix message queue

Is there an ipc option to get the last message in message queue but not removing it? I want this to allow many clients reading same messages from the same server.. Edit: Server and clients are on the same machine! Thanks ...

C++ program runs slow in VS2008

I have a program written in C++, that opens a binary file(test.bin), reads it object by object, and puts each object into a new file (it opens the new file, writes into it(append), and closes it). I use fopen/fclose, fread and fwrite. test.bin contains 20,000 objects. This program runs under linux with g++ in 1 sec but in VS2008 in debu...

Linux read command - simple question

Hi, why is output empty? echo "a b c d" | read X Y Z V; echo $X Thanks. ...

Customizing Router Firmware

Hi, i've got a netgear DG834 router, and i want to have a go at hacking the firmware on it to try and add a Wake on Lan option. Netgear let you download the source and the tools to build an image, but i'm not sure where to start. I've never programmed on a unix platform before, and never done any firmware hacking, just wondering if anyo...

How do I pass the resulting files from one grep pass to another so that I only grep through the subset with the second pass?

Hello All, I want to be able to take the files I found with my first grep statement, something like this for example: grep -r Makefile * And then pass the files found in that pass of grep to a second grep with something like this for example: grep {files} '-lfoo' How do I do this? I know there must be a way. Thank you. ...

[Linux] domain socket "sendto" encounter "errno 111, connection refused"

I am using domain socket to get values from another process, like A to get a value from B, It works well for months. But recently, A is failed during "sendto" message to B with "errno 111, connection refused" occasionally. I checked the B domain socket bind file, it is exists. I also do some tests in another machine, also works well. S...

Java Classpath Problems in Ubuntu

First off I'm running Ubuntu 9.10 I've edited the /etc/environment file to look like this: PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games" JAVA_HOME="/usr/lib/jvm/java-6-sun-1.6.0.20" CLASSPATH="/home/travis/freetts/lib/freetts.jar:/home/travis/freetts/lib/jsapi.jar:." I then run "source /etc/environmen...

What speech libraries are available in Linux?

When it comes to TTS (text-to-speech) libraries in Linux, what choices do developers have? What libraries ship with the majority of distros? Are there minimal libraries? What functionality does each library offer? I'm approaching this primarily from a C++ point of view, although Python would suit me too. ...

Why GPRS modem provides embedded TCP/IP stack

My colleague and I are mining the GPRS MODEM market for a module suitable for use with embedded Linux. During the market scan, we see that several vendors highlight that their MODEMs include an embedded TCP/IP stack. This makes me wonder: when we are using embedded Linux which already contains a TCP/IP stack and connects using PPP, wil...

SDLJava joystick events in a thread

I have a class which uses SDLJava to process events from multiple joysticks. When I put a 'main' in the class and run the file, all the joysticks are correctly detected and all events at received and processed in the class. When I add a 'run' method (which does the same as 'main') and run the class as a thread, all joysticks are detect...

Problem with Ruby script output being stored into a file

I have a Ruby script that outputs a heap of text. As an example: puts "line 1" puts "line 2" puts "line 3" # etc... (obviously, this isn't how my script works..) There's not a lot of data - perhaps about 8kb of character data in total. When I run the script on the command line, it works as expected: $ ./my-script.rb line 1 line 2 l...

Airmon-ng problem

When, I run the airmon-ng command, I do not get any wireless extension for my wireless network card like wlan0.What could be the problem?My wireless card is Atheros hence it is supported. Any help pliiiiiiz. ...

How can I link to a specific glibc version?

When I compile something on my Ubuntu Lucid 10.04 PC it gets linked against glibc. Lucid uses 2.11 of glibc. When I run this binary on another PC with an older glibc, the command fails saying there's no glibc 2.11... As far as I know glibc uses symbol versioning. Can I force gcc to link against a specific symbol version? In my concret...

How do I bring a processes window to the foreground on X Windows? (C++)

I have the PID for the process (and the name), I want to bring it to the front on linux (ubuntu). On mac I would simply do SetFrontProcess(pid), on windows I'd enumerate the windows pick out the one I wanted and call SetWindowPos(hwnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE); but I'm at a loss of what to do on linux. I've look...

Linux, monitor read rates of files

I have a custom application which has a bunch of files open. I can see the file handles open by a process using "lsof" and I can see the files being accessed using "watch -d 'ls -alh'" and watching the mtime/ctime. However, I would like to see the rate of data that is being read/written to these files. IE: I need to determine if one file...

Link one shared library static to my shared library

I am struggeling a little bit with some options for linking on a project I am currently working on: I am trying to create a shared library which is linked against 2 other libraries. (Lets call them libfoo.so and libbar.so) My output library has to be a shared library and I want to static link libfoo.so to the resulting library, but libb...

How communicate with pty via minicom or screen?

I am trying to provide an AT/Modem-like interface around some hardware. Follwing this post I have the server setting up a pty using openpty(). Now I can communicate with the server as expected with a client app that open the slave and communicates via read() and write() calls. However I would also like to be able to use either the scre...