linux

SMTP on C: STARTTLS via OpenSSL

Hi all! I am using openssl to build secure smtp connections to gmail.com:25. So I can successfully connect to the server and sends a command STARTTLS (I receive 220 2.0.0 Ready to start TLS). Then execute the following code without disconnecting: SSL_METHOD* method = NULL; SSL_library_init(); SSL_load_error_strings(); method = SSLv23_...

How to check if the block is present in a sparse file (for simple copy-on-write)?

How to get sparse block size and check if data is present at the given offset in sparse file in reiserfs/ext3 in Linux? I want to use it to implement simple copy-on-write block device using FUSE. Or I should better keep a bitmap in a separate file? ...

CPU Affinity Masks (Putting Threads on different CPUs)

I have 4 threads, and I am trying to set thread 1 to run on CPU 1, thread 2 on CPU 2, etc. However, when I run my code below, the affinity masks are returning the correct values, but when I do a sched_getcpu() on the threads, they all return that they are running on CPU 4. Anybody know what my problem here is? Thanks in advance! #defi...

Problem installing packages

I am installing Matrix on a Linux x86_64 multicore system. I receive a message: Warning message: In install.packages("Matrix", dependencies = TRUE) : package 'Matrix' is not available Sure enough, there are not many details on package troubleshooting. It appears that Matrix is available for x86_64, but it's not available in any repo...

Can Core Data be used on Linux?

This might be a stupid question, but I was wondering whether or not you can use the Core Data libraries on Linux at all? I'm planning how to build the server side of an iPhone app that I'm working on, and have found that you can use PyObjC to get access to Core Data in a Python environment, e.g. use Core Data in a TurboGears web applica...

Examining C/C++ Heap memory statistics in gdb

I'm trying to investigate the state of the C/C++ heap from within gdb on Linux amd64, is there a nice way to do this? One approach I've tried is to "call mallinfo()" but unfortunately I can't then extract the values I want since gdb doesn't deal with the return value properly. I'm not easily able to write a function to be compiled into...

pthreads_setaffinity_np: Invalid argument?

I've managed to get my pthreads program sort of working. Basically I am trying to manually set the affinity of 4 threads such that thread 1 runs on CPU 1, thread 2 runs on CPU 2, thread 3 runs on CPU 3, and thread 4 runs on CPU 4. After compiling, my code works for a few threads but not others (seems like thread 1 never works) but runni...

Difference between "machine hardware" and "hardware platform"

My Linux machine reports "uname -a" outputs as below:- [root@tom i386]# uname -a Linux tom 2.6.9-89.ELsmp #1 SMP Mon Apr 20 10:34:33 EDT 2009 i686 i686 i386 GNU/Linux [root@tom i386]# As per man page of uname, the entries "i686 i686 i386" denotes:- machine hardware name (i686) processor type (i686) hardware platform (i386) Additi...

rpmbuild generates RPM in which subdirectory

rpmbuild generates RPM under which directory? I checked the RPMS directory:- [root@tom adil]# ls /usr/src/redhat/ BUILD RPMS SOURCES SPECS SRPMS [root@tom adil]# ls /usr/src/redhat/RPMS/ athlon i386 i486 i586 i686 noarch [root@tom adil]# How to decide rpmbuild outputs in which of the above sub-directories? Is it controlled ...

A programmatic way to discover the number of CPUs and spec for each CPU/Core in Ubuntu Karmic?

A programmatic way to discover the number of CPUs and spec for each CPU/Core in Ubuntu Karmic? Bash or C/C++, Python, Perl are fine. Thanks! ...

Macros for GCC/G++ to differentiate Linux and Mac OSX?

Macros for GCC/G++ to differentiate Linux and Mac OSX? ...

How to make C program wait (on Linux) ?

How to make C program wait (on Linux)? (I need to use wait with MPI - I need C code please) ...

What is casper rw loop file and why do I need it to make saving persistant on usb flash drive?

Suppose I've installed linux on my flash drive. Why do I need something like casper loop file to make saving persistant? So files are being erased? Isn't flash drive the same as actual hard drive? I'm linux noob so be patient. Or it is because linux on flash drive is actually live cd on flash drive? Can it be installed just like it is in...

Where to find __sync_add_and_fetch_8?

I got errors when trying to use __sync_add_and_fetch: test8.cpp:(.text+0x90e): undefined reference to `__sync_add_and_fetch_8' collect2: ld returned 1 exit status Please kindly advise how to rectify this. Specs: GCC/G++: 4.4.1 GNU/Linux 2.6.32 SMP i686 Many thanks! EDIT: In addition to the answer provided, one can use -march=i586 ...

UUID library for C?

I'm looking for a UUID library for programming in C, that has a reasonable probability of being installed (or at least installable by package manager) on most modern Linux desktops, and works with pkg-config. The following two possibilities seem most obvious: OSSP UUID Libuuid from e2fsprogs Does anybody have experience with these t...

Using pam_python in a script running with mod_python

Hi ! I would like to develop a web interface to allow users of a Linux system to do certain tasks related to their account. I decided to write the backend of the site using Python and mod_python on Apache. To authenticate the users, I thought I could use python_pam to query the PAM service. I adapted the example bundled with the module ...

C++ Libraries similar to C#?

I'm coming to C++ from a .Net background. Knowing how to use the Standard C++ Libraries, and all the syntax, I've never ventured further. Now I'm looking learning a bit more, such as what libraries are commonly used? I want to start getting into Threading but have no idea to start. Is there a library (similar to how .net has System.Th...

Using a checked STL implementation, anything available for free?

Have you used a checked STL implementation? Did it find bugs you were not expecting? Is there one I can try on Linux for free? ...

How to convert PE(Portable Executable) format to ELF in linux

Hi What's the best tool for converting PE binaries to ELF binaries? Following is a brief motivation for this question: Suppose I have a simple C program. I compiled it using gcc for linux(this gives ELF), and using 'i586-mingw32msvc-gcc' for Windows(this gives a PE binary). I want to analyze these two binaries for similarities, using...

How the Google Chrome Linux version handles automatic version updation

Hello, Can some one tell me how the Chrome's Linux beta version carry out automatic version updation using debian package manager. I need to implement something similar to my application on linux and information provided here would be of lot of help. I am currently checking out the postinst script present in the debian control package an...