C is a general-purpose computer programming language used for operating systems, games and other high performance work and is clearly distinct from C++. Questions about programming in C are off topic and will be closed or migrated. Consider asking your question at Stack Overflow instead.

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What is the difference between working on a machine and doing the same task over ssh?

I have been working at University on a local machine which is on a server that I have access to. I have some c code and am able to carry out parallel runs of the code as expected. However when I ...
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1k views

Building GCC and Binutils on Windows 7 x64

I am trying to build GCC following the instructions in: Building GCC. At the moment I am building binutils but getting the error: * BFD does not support target x86_64-unknown-cygwin. Look in ...
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Can I sandbox a binary created in C (with GCC) for Linux and make it easy for users?

I have compiled a binary that I want to distribute to other people. It's closed-source, but I want to provide users of the binary with confidence that it cannot possibly access the internet, ...
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1answer
121 views

Record a process's User/System/Real time in Linux/Bash with greater precision

What I am looking for is something along the lines of /usr/bin/time, however, this usually does not have enough precision. I am running a C program (that I can edit and recompile) and I need to ...
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1answer
389 views

Get Physical NIC's Mac Addresses on Linux

I am trying to get the mac addresses of a Linux machine. I only want the physical NIC's though, not the virtual ones. I have been doing some searching and maybe I am not punching in the right terms ...
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1answer
539 views

Environment variable's address is changing?

Don't ask why I am not posting this at Stack. So I have this small C program. It returns the address of the environment variable specified in argv[1]. #include <stdio.h> #include ...
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1answer
1k views

execvp exec format error for shell script on Red Hat Enterprise Linux 6

We have two RHEL 6 systems that are running identical versions of the kernel and glibc (glibc–2.12–1.90.el6_3.6). According to the POSIX standard and the Linux man pages, if the kernel determines that ...
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1answer
24 views

The “other” finger (GECOS fields at /etc/passwd)

in the file /etc/passwd we have the so called GECOS fields (which stands for "General Electric Comprehensive Operating System"), that is: username:password:userid:groupid:gecos:home-dir:shell ...
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1answer
30 views

Setting up quarantine environment on Linux or Mac

How can I setup an quarantine environment so that I can test my codes or programs which can fork any number of times? I was trying this on Mac and if I have a fork in a while loop which is not ...
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1answer
58 views

How do I install programming info pages in Mac OS X?

I used to have a Linux system i was able to type info libc to view info pages on the C library, including unix functions. However, now I am running Mac OS X this does not work. How do I install the ...
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1answer
394 views

How to install gcc 4.4.7 on Mountain Lion

I need to install a specific version of the GNU GCC compiler, gcc 4.4.7, on my macbook, but I'm not sure how to do this. Most places I've found install later versions but I need to install that ...
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1answer
714 views

Does stat/lstat on nonexistent file cause a disk seek?

When searching for a library file from a right folder, my application currently does couple of lstat's for the possible locationslocations. Now I'm wondering whether these lstat's (application is ...
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1answer
27 views

How can I add a flag in PostgreSQL source code that works in both frontend and backend?

I'm trying to do some changes to postgresql source code. I want to add a flag that works in both frontend and backend. Here is what I have done so far. 1- I created my header file mine.h in which I ...
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1answer
43 views

C programs stuck

After installing windows 10 a couple of month ago i tryed to run a very simple C program, firtsly in Visual Studio 2015, and the entire IDE froze. Then I tried compiling via command line. The build is ...
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1answer
127 views

DD-WRT calling web service from Arduino ESP8266

I am looking for a way of finding out what devices are currently attached wirelessly to the router thats running DD-WRT firmware. Problem is that I am unable to find any references to a REST API or ...
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1answer
190 views

How to change the default terminal beep frequency of the PC speaker?

I want to change the default sound frequency ofSND_BELL(which is used when\aor BEL or ^G is printed on the screen) to higher values (the current default is around 750Hz). Of course this turn to need a ...
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1answer
35 views

Is there any difference in the view of process & sub process between command “/bin/sh -c ls /” and sh temp.sh(containing one line ls / only)?

What is the difference between the above ways of executing command and the code below? #include int main ( ) { int return_value; return_value = system ( "ls /" ); return return_value; }
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99 views

Gstreamer unable to link API's , Linker error

I was trying to read the PAT table information , Color Balance interface etc using gstreamer in ubuntu . but the the definitions of the API's used by gstreamer to achieve these are not available ...
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1answer
904 views

How do I set up the NVIDIA nvcc toolchain in Netbeans 8.0 in windows 8.1

I found a plug-in for the nvcc toolchain but it only works on linux. What I want is to be able to compile CUDA C code on my windows computer from within Netbeans. ATM I'm using Netbeans 8 and MS ...
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1answer
343 views

stuck on i2cmaster library

i want to try repair my batteries with smbus hacker code over arduino. first it was has some problems. i have tried to fix them and i fix. now i have problem on library i2c\test_i2cmaster.c.o: In ...
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1answer
77 views

running program in high priority -> does not log anymore

I have a project in visual C 2010 that needs real-time timing in high priority to eliminate stuff like hard disk maintenance and stuff. I ran the .exe file of my project using start "" /high & ...
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1answer
159 views

Cant compile SDL source file with gcc

i downloaded a manual of introduction to graphics programming with SDL, so i tried to compile my first source and it logged the next error the command to compile it was: $ gcc helloWorld.c [-o ...
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1answer
397 views

Which Package has net_tstamp.h?

I attempted to compile the source code here: http://os1a.cs.columbia.edu/lxr/source/Documentation/networking/timestamping/timestamping.c?a=x86;v=2.6.32 However, I got a compiler error: error: ...
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1answer
315 views

OSX: Remaining in terminal after C program executes

2nd edit Some clarifying... I wrote a C program that asks for input (in this case, using fgets()). When I compile it into a C executable, I notice this behavior: If I run the executable from the ...
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281 views

Makefile support for Tiny C Compiler

I just found the brilliant Tiny C Compiler while searching for a small portable C compiler for Windows (I cannot install anything on this system or copy files to it and so need to compile directly on ...
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1answer
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How do I find the installation path of binutils, gcc-3.4.4.tar.gz in Ubuntu?

I have ubuntu 8.10. In this I could find the binutils, gcc are installed. But when ever I try to know that glibc, glibc-linuxthreads are installed are not. It showing that no package is found. For ...
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1answer
345 views

C/C++ programs hang in Windows 7 console

I've installed Windows 7 Home Premium. It's working fine, except one major problem. When I run any C or C++ program in the console, using any software like Dev-C++, Code::Blocks or Visual Studio, it ...
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771 views

How to add “Read & execute” permission in Windows 7 for file on Samba drive

From a C program I would like to add "Read & execute" permission in Windows 7 for a file on a Samba drive. The "icacls" program is used in example below, but a C library call could also be a ...
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18 views

How can I recover my c drive after downloading SQL Server 2014 Express with Tools?

I downloaded SQL Server 2014 Express with Tools went through the entire process but the install file file kept running as if in a loop. I uninstalled the programs and affiliated drivers and now I keep ...
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0answers
20 views

how is envp argument passed to execve system call?

Suppose I call int execve(const char *filename, char *const argv[], char *const envp[]) where I malloced memory for envp, then how does the program filename access the contents of that array when ...
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pnmtopng on large file

I am running pnmtopng on a 101M, 3000x4000 pixel PNM file. I get the error pnmtopng: ASCII decimal integer in file is too large to be processed. every time I run it. I looked through the source and it ...
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382 views

So I stupidly install newlib, and probably overwrote references to glibc. How can I recover glibc?

I forgot to set a make --prefix and I think it wrote to /usr/local/ by default and now I'm having all kinds of errors. I'm on ubuntu natty, what's the easiest way to resurrect glibc. I've tried to ...
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17 views

prevent asl message to show up on /var/log/system.log

I'd like to define new asl facility in my project, and use it to generate asl log messages that wouldn't show up in /var/log/system.log (but only in the my pre-defined log file) here's my entire asl ...
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33 views

Why do these benchmarks NOT saturate the CPU.

I ran two trivial benchmarks in Powershell and C. I ran this on reasonably well endowed i7-2600 with 16 Gig Win 7 Pro. Both ran using two of the 8 cores (really 4 cores dual hyper threaded) and ran ...
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16 views

Building software on Arch and finding the dependency

I'm relatively new to compiling software. I downloaded a package called gr-scan which uses gnuradio and osmosdr (I have both installed and working via pacman already). The instructions say to edit the ...
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21 views

Slow IPC in 4000+ processes

I have an multiprocess application that is dependent on IPC calls. We have around 4000+ processes running. Currently we upgraded the system to RHEL 6.4, and now are observing that IPC calls msgrcv() ...
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8 views

valgrind impact on code execution?

I am starring at the following issue in OpenJPEG issues list: https://github.com/uclouvain/openjpeg/issues/571 The bug report states that code execution is different when run directly compared to ...
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124 views

build numpy from source results in wrong architecture

I build numpy from source on my mac to link it to my ATLAS library. Thus, I wanted to run it as described here with these options: export MACOSX_DEPLOYMENT_TARGET=10.10 export CFLAGS="-arch i386 ...
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74 views

Reset BT adapter through software on linux

I'm trying to reset the Bluetooth adapters using HCI sockets (in C) /* Open HCI socket */ if ((ctl = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI)) < 0) { perror("Can't open HCI socket."); ...
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145 views

How can I use older gcc headers?

I installed gcc-3.4 to Debian 7.8 and create symbolic link /usr/bin/gcc. When I typed gcc --version I get: gcc (GCC) 3.4.6 (Debian 3.4.6.-9) Then I wrote simple C program. #include ...
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47 views

how to download and install outdated linux-headers

I just watched the issue concerning how to add additional driver (module) into pre-compiled kernel; I tried to install the linux-headers but in the current repository I could find that all the ...
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How can I know if SNMP Walk or a Table-View is started?

Hello how can I know if a User has "sent" a SNMP-Walk or a TABLE-VIEW request to a device with UCD-SNMP/NET-SNMP and custom coding?
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103 views

How to force only Chrome to send network traffic through selected IP interface (not system default) on Windows 7?

I have connected to multiple network interface (like LAN, WiFi, USB modem, VPN) and I want Chrome to use the DNS servers from selected network (BUT NOT SYSTEM DEFAULT means local network) and also ...
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0answers
18 views

Can a subprocess launched from a parent executable access the memory of its parent?

Given a system() call with user controlled input, is it possible to read the virtual memory of the parent program? Assume that the system call is made with dropped privileges, and that running ...
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145 views

How to send COOKIE, PHPSESSID from my own webserver to php5-cgi script to execute PHP pages

I am developing a Webserver in C. I know how to pass environment variables to ph5-cgi, eg: putenv("QUERY_STRING="); putenv("REQUEST_METHOD=GET"); putenv("REDIRECT_STATUS=true"); ...
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303 views

Ctrl-D does not do what it's supposed to in Cygwin on Win7, according to C tutorials

I'm following examples in the book Head First C, and I'm supposed to enter strings at the command line for the program to encrypt, then ctrl-D when I'm done. But ctrl-D doesn't have any effect.
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454 views

apache httpd libapr linking .a .so

Problem I need to compile and install an Apache module on AIX 6.1. This is the module A. The Apache module is available only as source. I manageg to compile the source and the .so module was ...
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433 views

What would cause different rates of packet loss between client and server in UDP?

If I've implemented a reliable UDP file transfer protocol and I have a file that deliberately drops a percentage of packets when I transmit, why would it be more evident that transmission time ...