-1
votes
0answers
15 views

Use fts(3) functions to rename files and directories. only first level gets changed [migrated]

it's just a simple prog to replace spaces with underscores. i found a bash script that will do it but it's slow. from what i understand i want a depth-first search and i want my remove_space function ...
0
votes
0answers
54 views

How to cause memory fragmentation on a Linux based embedded device?

Hardware ARM What am I trying to do: Answer: I am trying to create memory fragmentation on a Linux 2.6.31 based swapless embedded device. Why: Answer:I am trying to port some patches to Linux ...
1
vote
2answers
82 views

Writing own daemon. systemd error: Failed to read PID from file: Invalid argument

I'm trying to write own daemon a la very simple MPD (it's operating systems laboratory work). I made it work: it starts like a daemon (output of ps): 1 14877 14877 14877 ? -1 Ss 0 ...
2
votes
1answer
796 views

Start 4 programs on startup in Linux Mint via terminal

I'm working on a project and I hope you can help me solve a problem. I have four programs that are written in C. They have been compiled using gcc and they work as they should. Because the four ...
2
votes
2answers
504 views

Why does Linux have a C compiler by default?

Why does a Linux distribution have gcc installed in advance? Is it because most of the applications in linux are written in C? What would happen if the gcc directory is deleted?
3
votes
0answers
131 views

Fork vs. thread system time [closed]

I got the following logs: Program 1: Taken from a program executed 64 fork calls: real 0m0.023s user 0m0.068s sys 0m0.008s Program 2: Taken from a program executed 64 thread calls: real 0m0.613s ...
2
votes
1answer
143 views

Dependencies problem with automake

I am using automake on Debian Squeeze for compiling a very simple C project with 6 source files. The issue comes when I try to compile the sources using the generated Makefile. One of the sources ...
0
votes
1answer
126 views

Understanding a XINU system call - getstk.c [closed]

I am having trouble conceptually understanding what is going on towards the end of this system call, and why. I understand the getstk.c method returns the highest memory address of available space, ...
2
votes
2answers
258 views

Why read() is slower than getc()? [closed]

Why is read slower than getc? For example, this: for (;;) { chr++; amr=read(file1, &wc1, 1); amr2=read(file2, &wc2, 1); if (wc1 == wc2) { if ...
0
votes
1answer
219 views

USB-Serial Driver(Exar Xr21v1414) Run Error

I'm currently trying to run the bellow driver in linux-3.8.3 on Exar xr21v1414 http://www.exar.com/connectivity/uart-and-bridging-solutions/usb-uarts/xr21v1410, but when i install the driver ...
1
vote
1answer
129 views

How to explicitly load shell interpreter in a C program

I want to create an executable script which is not readable/writable However since an interpreter needs to read this file it is not possible to do so directly. Therefore I wanted to know if I could ...
-1
votes
2answers
82 views

Why rsh not opens and reads PAM modules and limits.conf?

I am working on a project, that uses rsh utility for remote connection. But my project needs some extra features for that, so I add that features. Till now, all the things are going fine. But when I ...
0
votes
2answers
129 views

Which process updates /proc/scsi/scsi?

I wrote C that displays info about my hardware on ubuntu. Now I wonder how I can make it more flexible such as querying the hardware directly instead of the file the os updates. So I think I can look ...
0
votes
1answer
112 views

Having trouble executing a compiled C program

I am running an Ubuntu v10.04 through VirtualBox. To test the persistence of files I create in the virtual machine, I wrote a very basic C program. When I shutdown the virtual machine and restart it, ...
2
votes
3answers
232 views

Linux GCC compiler options

I have recently started using Linux as a tool for programing. In my book, I have seen that the GCC is used with 2 options: -g and -o. Now, I know that -o is to set a filename, but what is the purpose ...
2
votes
2answers
726 views

USB Driver Compilation Error

I'm currently trying to compile a Linux USB UART driver, which is provided here: http://www.exar.com/connectivity/uart-and-bridging-solutions/usb-uarts/xr21v1410 The driver consists of 2 header files ...
3
votes
1answer
265 views

IP_TRANSPARENT missing from glibc headers

I'm trying to use the IP_TRANSPARENT declaration. I am using debian 6.0.5. IP_TRANSPARENT is only defined in linux/in.h however it conflicts with netinet/in.h. In centos for example, IP_TRANSPARENT is ...
2
votes
2answers
2k views

How does copy-on-write in fork() handle multiple fork?

According to wikipedia (which could be wrong) When a fork() system call is issued, a copy of all the pages corresponding to the parent process is created, loaded into a separate memory location by ...
0
votes
1answer
532 views

pcap and raw socket [closed]

I want to develop an application (module or user-level if possible) to create a raw socket in RHEL stealing all level-2 packets directly from kernel (without being routed or handled by other open ...
3
votes
1answer
810 views

Does free() unmap the memory of a process?

I am running a C program on Linux 2.6.16 kernel. I do not think there are memory leaks in my program however the memory consumption for the program remains stable after certain operations and does not ...
2
votes
4answers
418 views

/usr/bin/which returns cryptic error “which: no ls in ((null))”

I am writing a simple shell program. When I use /usr/bin/which with my shell in mac osx and ubuntu, it acts normally. When I use the exact same command on Red Hat Enterprise Linux Client release 6.3 ...
4
votes
1answer
891 views

How to create a fake device file that accepts input from a C program?

I want to create a C program that accepts input from a joypad (/dev/input/js0), processes it, and then sends it to a fake device file (character or block) labeled as a keyboard (oh, and what is the ...
2
votes
1answer
1k views

/dev/tcp not present in Linux

I am porting C/pro*c code from UNIX to Linux. The code is: #define __NFDBIT (8 * sizeof(unsigned long)) #define __FD_SETSIZ 1024 #define __FDSET_LONG (__FD_SETSIZ/__NFDBIT) typedef struct ...
1
vote
1answer
493 views

How to preload my .so everytime an application executes?

I've successfully used a hook under linux with this article: http://hackerboss.com/overriding-system-functions-for-fun-and-profit/ Now I want to make my .so file load every time espeak loads up. No ...
2
votes
1answer
236 views

What is parallel memory allocation?

I'm trying to understand what parallel memory allocation is. I think I understand what 'memory allocation' is but I don't understand the term 'parallel'. Something to do with multiple processors ...
1
vote
1answer
334 views

Dynamic linker “no version information available”

When I copy over a program and a few libraries it needs to another machine I get the "no version information available" when I run LDD on the program. I know why this is happening, I just want to ...
2
votes
1answer
1k views

gcc: -pthread: No such file or directory

Trying to compile following code in terminal i got gcc: -pthread: No such file or directory, what does this error means and how to eliminate it? file name: window.c code: #include ...
0
votes
2answers
330 views

Why Samba needs the VFS module?

I came across this picture when learning samba. I am confused with the VFS module in this image. Why we need this VFS module in samba server instead of passing directly the intend system call to ...
2
votes
1answer
1k views

How to capture from instensive pro in Ubuntu, Fedora, CentOS using HDMI interface?

I am trying to use PCI-X1 capture card (intensiy pro) using Ubuntu 10.04 (now) / 11.04 (failed) or Fedora (failed). None of them is yet capturing. I did my best but now i need some backup on this. ...
4
votes
2answers
4k views

“sys/ioctl.h” header in linux

I am on Linux 2.6.32-26-generic When I look in to the linux source code for "ioctl.h" hearer file, I could see many variants. (for different platforms, I guess). i.e. ./fs/ocfs2/ioctl.h ...
14
votes
3answers
8k views

What are pseudo terminals (pty/tty)?

This might be really basic question but I want to understand it thoroughly. What is a pseudo terminal? (tty/pty) Why do we need them? How they got introduced and what was the need for it? Are they ...
5
votes
3answers
3k views

How do I kill all a user's processes using their UID

I want to kill all running processes of a particular user from either a shell script or native code on a linux system. Do I have to read the /proc directory and look for these? Any ideas? Is there a ...
0
votes
3answers
166 views

What to change to place text in the centre of the screen [closed]

The following program will clear the screen #include <stdio.h> int main() { fputs("\033[2J", stdout); return 0; } So, what should I modify/add in the above code to put a text string ...
0
votes
1answer
3k views

how to Update gcc of OpenSuse 11.2?

I have OpenSuse 11.2 with gcc version 4.4.1. I would like to update my gcc version to 4.5.1. I have downloaded gcc-4.5-19.1.i586.rpm. When I rpm install it, it's asking for ...
6
votes
4answers
8k views

make a log file

Is there any way to make a log file for maintaining some data in /var/log/ with the help of some library function or system call in c language in linux. And I also want to know the standards that we ...
1
vote
1answer
261 views

Recording and charting boot process information in Linux

I need to write a command line tool that records the boot process information in Linux, and then renders it in a chart format (a textual chart would do). How do I programmatically obtain the this boot ...
5
votes
1answer
2k views

How can i know which unistd.h file is loaded?

I have several unistd.h files in my Ubuntu Linux. I've one on: /usr/include/asm/unistd.h This file has this directives: # ifdef __i386__ # include "unistd_32.h" # else # include "unistd_64.h" # ...