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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Reading the program header contents of an ELF file

How is it possible to extract loadable program headers individually from ELF files? By examining a binary using readelf one can get output similar to: $ readelf -l helloworld Elf file type is EXEC ...
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0answers
23 views

Linux command inside C code: /* treat as comment? [migrated]

In C, I want to run linux command. Namely, int status; status=system("lftp ftp://192.168.1.1 -e "mget -E /2015/Date*/*Snap/*.csv"); The * above is wildcard matching. The C compiler thinks this is ...
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1answer
724 views

ioctl: invalid argument for HDIO_GET_IDENTITY

I wrote a program to get the details of hard disk drive using HDIO_ ioctl calls. For writing program, I'm referring Documentation/ioctl/hdio.txt in kernel source(2.6.32). Here is my main part of ...
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0answers
28 views

Refreshing C, did you think my code is world class, or very good [closed]

stackexchange.com/ Due to been unable to ask a C programming language expert or advanced user in person I'm posting this simple question about my C code, today I was refreshing my C with exercise 5.4 ...
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1answer
40 views

introduce a c script in a bash file [closed]

My problem is to recover data keyed in text file in bash. I seek the command that can perform this task and I used sed, awk and even cut but I have not succeeded. One friend of mine suggested to ...
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1answer
34 views

How do I execute a parted command with a C function?

I would like to execute the Linux command "parted" through a C language function? I am using Linux Ubuntu , eclipse. Thanks!
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0answers
19 views

How to obtain block device label [duplicate]

I have a tricky problem. I have a block device connected to SLES11, it is present in /proc/partitions but it is not mounted (not present in /proc/mounts). From C code I want to find the block device ...
1
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1answer
92 views

Reading the contents of an ELF file (programmatically) [closed]

I am trying to retrieve the contents of an additional section within an ELF binary. At this point, I'm using the following code to retrieve the name of each section: #include <stdio.h> #include ...
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1answer
17 views

Pulling log messages for a particular log in systemd journal?

I was wondering if it is possible to pull log messages for a particular log with systemd's journal logging. For example, when I open a log in C, openlog('slog', LOG_CONS | LOG_PID, LOG_LOCAL1), to ...
2
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1answer
888 views

what device name should I have to give in snd_pcm_open other than “default”

I want to record sound from 2 devices simultaneously: internal mic external usb webcam mic Using pulseaudio sound controller, I set either of these devices as default and could record sound with ...
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1answer
27 views

How to run smartctl as root without switching to root?

I have this C code that runs smartctl command and takes its output: #include <iostream> #include <cstdio> #include <cstdlib> using namespace std; int main() { cout << ...
0
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1answer
33 views

Trying to make a Universal Makefile

I'm working on my own netfilter module for the first time. According to internet documentation, The simplest module contains the following C code: //'Hello World' kernel module, logs call to ...
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3answers
65 views

loop test strings to see if input is valid for C program input

For example I have a file filled with some pretty gnarly strings. 12345678900 1111111111111111111111111 ...
0
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1answer
66 views

C/C++: Running multiple commands as root

I want to execute commands within my C program. However, I need root priviliges to create some folders. I run the following: system("echo <rootpass> | sudo cd <folder> && make ...
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votes
1answer
55 views

how to return file descriptor in c [closed]

I am confusing with this. fp=fopen(filename,mode); what is the value fopen() return to fp. is that value is file descriptor integer? is fp called as stream ? if not how to return a ...
0
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1answer
44 views

How to select read/write time and again? [closed]

This program only waits one time and I don't understand why. Actually, I don't think this question should be put on hold as off-topic. #include <stdio.h> #include <sys/types.h> #include ...
2
votes
2answers
58 views

linux setuid does not work

I am learning linux suid,so I have written a small c program with the following content to test it #include<stdio.h> int main(){ system("echo 100 >> test.txt"); return 0; } -rwsr-xr-x 1 ...
0
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1answer
384 views

“fatal error: stdio.h : No such file or directory” while compiling a C file [closed]

Trying to compile following code in terminal i got root@debian:/home/mz2/Documentos# LANG=C ./soma.c ./soma.c: line 2: syntax error near unexpected token `(' ./soma.c: line 2: `int soma (int a, int ...
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0answers
42 views

keyboard still working after calling free_irq(1, NULL);

I'm developing a kernel module which free the IRQ number 1 in order to disable the keyboard in Intel architectures. according to wikipedia the IRQ 1 is used for keyboard. but after building and ...
17
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4answers
1k views

How to dump a binary file as a C/C++ string literal?

I have a binary file I would like to include in my C source code (temporarily, for testing purposes) so I would like to obtain the file contents as a C string, something like this: \x01\x02\x03\x04 ...
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0answers
20 views

how to define the top dir in automake system?

I usually use a typical steps to generate the makefile, and firstly I use the "build.sh init" to generate the configure file, and then I use "configure" to generate the makefile with makefile.am file. ...
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1answer
135 views

Compile OS with gcc and ld on Linux

I'm practicing operating system development and am having trouble getting gcc and ld to produce pure binary without any metadata or section labels. For example: int function(){ return 100;} would ...
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1answer
396 views

Cabal error: Cannot run c compiled programs

I have an old version of cabal-install so I downloaded cabal-install 1.20 and When installing it errors out. Additional note: ghc 7.8.3 OS: CentOS 6.6 Error: Building network-2.4.2.3... ....... ...
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1answer
152 views

Cannot find -lgcc

I'm trying to compile my next basic c program after hello-world. This contains two supporting modules. I have Ubuntu running in a VM through VirtualBox on a mac. Everything is up to date but I ...
5
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4answers
7k 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 ...
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0answers
1k views

Getting “cannot open shared object file: No such file or directory” error while run time

I have successfully compiled the file but now I am getting following errors export LD_LIBRARY_PATH=/opt/mcr/v717/sys/java/jre/glnxa64/jre/lib/amd64/server/:D_LIBRARY_PATH ./invoke ./invoke: error ...
2
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2answers
212 views

How does a parallelized Python program look with top command?

I work on a shared cluster. I've seen people run parallelized c code on this cluster which, when I use top to see what processes are running, are shown to be using (for example) 400% of the CPU, ...
0
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1answer
21 views

-fPIC Flag System-wide?

Position Independent Code means that the generated machine code is not dependent on being located at a specific address in order to work. and the jumps are relative. So is it OK to declare -fPIC ...
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0answers
45 views

Linux and Embedded systems engineering [closed]

First of all I hope everybody had a great weekend. My question is simple. Which version of linux is best suted for embedded software engineering and programming. Thank You AO!
2
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1answer
92 views

How to compile manual files .1

I have .c, .h, and .1 files, how can I compile them together in one executable file. Everything clear with .c and .h files, but I have also .1 as I can see from the content it is used for manual, how ...
176
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4answers
60k views

Why is FreeBSD deprecating GCC in favor of Clang/LLVM?

So I was surfing the net and stumbled upon this article. It basically states that FreeBSD, starting from Version 10 and above will deprecate GCC in favor of Clang/LLVM. From what I have seen around ...
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2answers
111 views

How can I link my C program against the Arb library?

I tried to compile the program Testing Li’s criterion in Ubuntu. However, when I do gcc demo.c, I get the output as, demo.c:2:19: fatal error: fmpcb.h: No such file or directory #include "fmpcb.h" ...
1
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1answer
214 views

Linking a static library when compiling a C program

I'm linking *.a file with *.c file, so I have used the following command: gcc abc.c -l ad.a (here abc is the C source file and ad is the static library file) then after executing the following ...
3
votes
1answer
122 views

Read .desktop files programmatically [closed]

I would like to make a C program (GTK) that reads a .desktop file. The only thing I need from the .desktop file is the exec command. Is there something built into GTK that would allow me to interact ...
2
votes
2answers
100 views

assign output of a c program to a shell variable: token error

I have a shell script to run several times a .c program ('switch') which admit 3 input paramenters. I want to run the program 4 times passing values {4,16,32,64}, and for parameters ...
4
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2answers
1k views

How to check whether a process is daemon or not?

I have written a small daemon that starts at the boot time and does all the things perfectly like writing in the log file. But I want to know, how can we check whether that process is daemon or not? ...
0
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1answer
98 views

Linux [admin] How to test pivot_root?

I want to test the pivot_root command line, which moves the root file system of the current process to the directory put_old and makes new_root the new root file system. ...
1
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0answers
84 views

PAM authentication program in C recognizes only the logged in user [closed]

I am trying to write a C program to authenticate users using PAM. Here is what I have at present: #include <security/pam_appl.h> #include <security/pam_misc.h> #include <stdio.h> ...
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1answer
27 views

snd_rawmidi_open() waits forever - no error message

I am trying to use ALSA for MIDI purposes in C. My problem is, snd_rawmidi_open() sort of "crashes" (waits forever like a while loop) when using valuable arguments : #include <stdio.h> ...
2
votes
0answers
37 views

Make GNU indent break long comments

Is there a way to convince GNU indent to break long comment and change it to multiline comment? Something like this: // Very long comment, longer than 80 characters. Just imagine that. To this: /* ...
2
votes
2answers
484 views

Linux cannot compile without GCC optimizations; implications? [closed]

One can find several threads on the Internet such as this: http://www.gossamer-threads.com/lists/linux/kernel/972619 where people complain they cannot build Linux with -O0, and are told that this is ...
9
votes
3answers
7k views

Man pages for standard C and C++ libraries on Fedora 14

How do I install them? At present, man fopen gives me No manual entry for fopen. I have the compilers installed and have verified that things do build without problems. Update: This is what I got ...
4
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1answer
125 views

How to compile programs on Linux systems when I don't have sudo privileges to install the dev dependencies [duplicate]

How should I go about compiling programs that depend on libraries whose development packages (headers and such) aren't pre-installed on the system when I don't have sudo access? In this particular ...
3
votes
1answer
226 views

How to create GUIs (such as menuconfig) with lxdialog

I try to generate a menuconfig by my own with the help of lxdialog (source: lxdialog). Unfortunately this is not so well documented as I wished for. Example: So what I did: I included these files ...
6
votes
1answer
36k views

gcc can't link to pthread?

I have recently installed XUbuntu 11.10 64bit, but I am having problem compiling the most simple pthread example. Here is the code pthread_simple.c: #include <stdio.h> #include ...
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0answers
32 views

Inotify notifies only single change

I set the inotify_add_watch to watch /dev/disks. The entries in this directory are: by-id and by-uuid. When I plug-in a pen-drive, this directory gets added with two more directories: by-path and ...
1
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0answers
34 views

CPUFreq Kernel module

I would like to try the CPUFreq module on my board (Marvell Soc based on ARMv7 running a v3.15 linux kernel). My architecture is obviously not supported by the default source code (located in the ...
5
votes
4answers
2k views

chdir(<directory>) doesn't change directory after exiting to shell

I wanted to make a simple C program to change to my project directory. Its content is following: #include <unistd.h> int main(){ chdir("/home/enedil/projects/algo"); return 0; } I ...
0
votes
1answer
58 views

What are the disadvantages of uClibc?

I try to speed up my boot sequence, and somebody recommends to use the uClibc instead of Glibc. I've built an image with it, it gets smaller and faster to boot — but at which cost? Does anyone know ...
3
votes
2answers
609 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 ...