C is a general-purpose computer programming language used for operating systems, games and other high performance work and is clearly distinct from C++. It was developed in 1972 by Dennis Ritchie for use with the Unix operating system.

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In makefile when do we use .o files?

In the following make file, what is the significance of adding .o files instead of .c files? CC=gcc CFLAGS=-I. hellomake: hellomake.o hellofunc.o $(CC) -o hellomake hellomake.o hellofunc.o ...
5
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2answers
344 views

What would I get when sudo a kernel-destructive program?

It suddenly comes to me how easy it will be for a sudoer to crash the kernel, so I tried something like this: #include<stdio.h> int main(){ printf("hello world"); int a; ...
3
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1answer
916 views

Error compiling FTDI VCP drivers: Cannot find version.h

driver installation fails of FTDI VCP driver during make install. Running ElementaryOS with kernel 3.11.0-14-generic make install awk: cannot open ...
2
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0answers
194 views

Writing to Arbitrary Memory Addresses [closed]

I'm reading "Art of Exploitation 2nd Ed." and I have a question regarding a section on format string attacks. Target program Below code (fmt_vuln.c) is a target program. #include <stdio.h> ...
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3answers
123 views

Is there any manual about C in Linux? If any, what is it?

While I find that we can read some manuals about Library calls (C library functions) & acsii in Linux. But I still do not find any manual about C precedence order so far. So you can recommend ...
2
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2answers
341 views

How to make processes not die after its parent dies?

I've been messing with forkbombs and noticed that if I just fork() processes repeatedly, killing the initial process will bring down the whole tree. This is not the case for forkbombs written in BASH ...
3
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2answers
105 views

How to write software to compile with external libraries?

I want to code open source software with dependencies. I have skills in C/C++ and a minimum makefile knowledge. But im curious about coding this like ./configure && make stuff and how to ...
2
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1answer
2k 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 ...
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1answer
100 views

C-library HMAC_MD5 questions

We are working with an older software product that has some limited programming capabilities - specifically, no bit manipulation functions. This has created a significant problem as we need to ...
0
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1answer
180 views

Read and parse XML input via TCP [closed]

I'm setting up something where I'll need to be able to setup a service that accepts input on a TCP port and then parses the XML provided and extracts the necessary data, then posts that to Google's ...
5
votes
1answer
530 views

command substitution handling in fish vs. other shells (sh, bash, zsh)

The program mc (Midnight Commander) is not intended to be used for command substitution, but I would like to know why different shells behave differently when this program (and it seems like other ...
3
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2answers
690 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?
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1answer
175 views

Parsing protocol and url from packet payload

We are using pf_ring to capture packets. We are able to decipher information like source and destination ip, mac etc from the header information. Now we are moving into payload to decide the type of ...
3
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0answers
154 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
256 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 ...
10
votes
2answers
224 views

Is there a way to mirror USB outputs?

I'm currently writing a program for a project. It is for a braille reading system where I have a braille display connected via USB that is controlled by a program called brltty. One of the ...
1
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1answer
211 views

How to trace process scheduling of certain process?

For a project at my university I am researching ways to trace, log and manipulate the process scheduling of certain processes. I would like to launch an number of applications, everyone in a single ...
4
votes
4answers
777 views

Is it possible to make multi-level directory? [duplicate]

Using mkdir() (the C function) I can create a 1-level directory, if I want to create multi_level directory like: folder/subfolder/subsubfolder is it possible? if so, how?
4
votes
1answer
278 views

Effect of static and dynamic linking on start address

I have a simple C program. I run: $ gcc Q1.c -Wall -save-temps -o Q1 Then I inspect the executable generated: $ objdump -f Q1 Q1: file format elf32-i386 architecture: i386, flags 0x00000112: ...
3
votes
3answers
670 views

default wordsize in UNIX/Linux

I was inspecting the preprocessed output of my C program and happened to look at the header file wordsize.h It is located in /usr/include/i386-linux-gnu/bits/wordsize.h the file contains only one ...
4
votes
1answer
114 views

Portions of the file Header

I was working through my C programs, I am new to Linux/UNIX development and was having a look around. I created a simple C program of Hello world and was inspecting the compilation process. I tried ...
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4answers
2k views

I can not get my Realtek 8723 driver source compiled

I have a Lenovo IdeaPad Yoga 13. WLAN won't work out of box with fedora 18. So I googled around and found this 2 links: ...
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votes
2answers
294 views

Using file system call

I'm trying to learn system calls for open,write and close a file. I use this sample and the result is: gcc: error trying to exec 'cc1plus': execvp: No such file or directory Here's my program: ...
0
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1answer
231 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
303 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 ...
1
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2answers
366 views

Monitoring script started by rc.local

We have a C program which is started using rc.local´. We added a line like this: /usr/local/bin/pc to the rc.local file. pc is a compiled C program. Everything is working fine at the moment. What ...
0
votes
1answer
376 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
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1answer
280 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 ...
0
votes
1answer
74 views

Can a GTK applet widget be instantiated through dbus?

I just posted this: #274616: “Simple” gnome applets in Unity - stickynotes ... where I could instantiate a Gnome 2 bonobo applet in a standalone window, ... using ...
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2answers
107 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 ...
3
votes
1answer
223 views

Make Completion Progress Script

Any time I'm executing a build process that takes several hours, I inevitably stare at my terminal and wonder, "how much longer?" Sometimes, I manually pick up on some pathname echoed to the terminal ...
-1
votes
3answers
518 views

telnet implementation using C [closed]

The program in general is I want to implement telnet program. On the client side user send its logging name and password, and if it is correct he starts to send commands to the server On the Server ...
0
votes
2answers
182 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 ...
1
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0answers
224 views

mod_rewrite: undefined symbol: lstat error

I compiled the mod rewrite for apache (version 1.3.0) however, when I try to run the server I have this error about mod_rewrite: Syntax error on line 27 of /home/myuser/apache/etc/httpd.conf: Cannot ...
3
votes
1answer
752 views

Send log messages to a different location

I want to send messages from C program and from Perl script to a file (for example, /var/log/my_log). I don't have access to the syslog daemon configuration, so I think in launch a differente syslog ...
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votes
2answers
89 views

Which Linux distro/mode offers lowest interference when running your own applications?

I'm interested in a Linux distro to build C projects and test their behavior in a very predictable and controlled environment. I'm especially concerned about letting the scheduler deal as much as ...
0
votes
1answer
138 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
365 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
1answer
492 views

Conky - string formatting

I have conky the record: ${color lightblue} Down: ${downspeed wlan0} Up: ${upspeed wlan0} Conky prints link speed, but the text moves: Down: OB Up: OB Down: 60B Up: 60B Down: 148B Up: 148B ...
1
vote
1answer
802 views

How do I write a login daemon?

There are many guides to the steps for correctly launching a daemon process, such as Stevens' chapter in Advanced Programming in the UNIX Environment. There is less agreement on what steps should be ...
1
vote
1answer
235 views

Linux kernel 3.2 syscalls

Just trying to get the assembler instructions for <__execve> of the code below because i want to build the shell spawn opcode list: #include <stdio.h> int main() { char *happy[2]; ...
2
votes
2answers
1k 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 ...
1
vote
1answer
99 views

How do I keep 'indent' from moving curly braces to the next line?

I have several empty inline function definitions in C++ like so: class C { void foo(){} void bar(){} }; now if I run indent -st -i4 -nut test.cc in order to just fix the indentation I get ...
2
votes
0answers
101 views

Command-line file reader (like “less”) that can tell the line where the user stopped reading

[Context] I'm developing a little app, as a hobby to learn ncurses, that catalogs and lists and searches within a set of documents (for now, they are the HOWTOs from TLDP). The most tricky part of ...
2
votes
2answers
3k views

Calculating total CPU system usage in C [closed]

I found this answer on StackOverflow for calculating total CPU usage: http://stackoverflow.com/questions/1420426/calculating-cpu-usage-of-a-process-in-linux/4497769#4497769 But how do I calculate ...
1
vote
1answer
347 views

Writing a service in C: How to pass and process arguments to running service?

I want to write a service in C. While this service is running in background and processing some information I need to grab the results from this service from other applications or from command line. ...
3
votes
1answer
343 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 ...
3
votes
2answers
3k 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 ...
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0answers
167 views

Having problems with script and redirecting input to stdin [closed]

EDIT: found mistake, it was actually bug in my program, I had > instead of >= in my for loop that reads coefficients. I'm fairly new to linux, and I need help with bash scripting. I have C program, ...
3
votes
2answers
539 views

How to adjust time command to measure a program elapsed time

I'm trying to get the time that my program takes to finish (aka elapsed time) so I'm using the common time. What I get by doing this is 3 measurements: user, system and total. This is fine but I ...