Search Results

Search found 24623 results on 985 pages for 'linux'.

Page 523/985 | < Previous Page | 519 520 521 522 523 524 525 526 527 528 529 530  | Next Page >

  • What is the Effect of Declaring 'extern "C"' in the Header to a C++ Shared Library?

    - by Adam
    Based on this question I understand the purpose of the construct in linking C libraries with C++ code. Now suppose the following: I have a '.so' shared library compiled with a C++ compiler. The header has a 'typedef stuct' and a number of function declarations. If the header includes the extern "C" declaration... #ifdef __cplusplus extern "C" { #endif // typedef struct ...; // function decls #ifdef __cplusplus } #endif ... what is the effect? Specifically I'm wondering if there are any detrimental side effects of that declaration since the shared library is compiled as C++, not C. Is there any reason to have the extern "C" declaration in this case?

    Read the article

  • Using vim, how do you quickly refresh a web page you're working on?

    - by aLostMonkey
    I've been using VIM for a few weeks now while messing with various web languages and I'm really enjoying it. I find it cumbersome having to tab or click into my browser and refresh the page to see the effect of a code change. It's even more annoying as I'm using Virtual Box and I tend to be working from PDF files on the host system so I have limited window space. Do you gurus have any fancy ways of doing this? I was wondering if it's possible to split the VIM workspace and have links/lynx in a window of its own or something to that effect?

    Read the article

  • how to make this "action-packed, random data" being echoed in a terminal?

    - by RiMMER
    OK, this isn't really a question to achieve anything practical, but still it is a serious question and I hope it will be taken seriously and mods won't punish me for this :) I'm sure majority of you have seen some good action movie, where CIA or FBI or hackers or any other "pc nerds" are "retrieving some information" and when they actually show their screens/monitors/desktops, there is a lot of random data being displayed and it's just so thrilling :D So, we're shooting a movie and I need to reconstruct such a scene. My OS is ubuntu 10.10. I think i've read somewhere on the internet once that shell can actually be recorded and then played back, but I'm not sure how it worked. If there's anyone who could come up with a solution, it would be so cool! Let's make this fun, shall we?

    Read the article

  • Create Directory, 'cd' to it and download a file pipeline in Perl

    - by neversaint
    I have a file that looks like this: ftp://url1/files1.tar.gz dir1 ftp://url2/files2.txt dir2 .... many more... What I want to do are these steps: Create directory based on column 2 Unix 'cd' to that directory Download file with 'wget' based on column1 But how come this approach of mine doesn't work while(<>) { chomp; my ($url,$dir) = split(/\t/,$_); system("mkdir $dir"); system("cd $dir"); # Fail here system("wget $url"); # here too } What's the right way to do it?

    Read the article

  • What to do if exec() fails?

    - by Grigory
    Let's suppose we have a code doing something like this: int pipes[2]; pipe(pipes); pid_t p = fork(); if(0 == p) { dup2(pipes[1], STDOUT_FILENO); execv("/path/to/my/program", NULL); ... } else { //... parent process stuff } As you can see, it's creating a pipe, forking and using the pipe to read the child's output (I can't use popen here, because I also need the PID of the child process for other purposes). Question is, what should happen if in the above code, execv fails? Should I call exit() or abort()? As far as I know, those functions close the open file descriptors. Since fork-ed process inherits the parent's file descriptors, does it mean that the file descriptors used by the parent process will become unusable?

    Read the article

  • How can I determine if a file is read-only for my process on *nix?

    - by user109078
    Using the stat function, I can get the read/write permissions for: owner user other ...but this isn't what I want. I want to know the read/write permissions of a file for my process (i.e. the application I'm writing). The owner/user/other is only helpful if I know if my process is running as the owner/user/other of the file...so maybe that's the solution but I'm not sure of the steps to get there.

    Read the article

  • Replacing whitespace with sed in a CSV (to use w/ postgres copy command)

    - by Wells
    I iterate through a collection of CSV files in bash, running: iconv --from-code=ISO-8859-1 --to-code=UTF-8 ${FILE} | \ sed -e 's/\"//g' | \ sed -e 's/, /,/g' \ > ${FILE}.utf8 Running iconv to fix UTF-8 characters, then the first sed call removes the double quote characters, and the final sed call is supposed to remove leading and trailing whitespace around the commas. HOWEVER, I still have a line like this in the saved file: FALSE,,,, 2.40,, The COPY command in postgres is kind of dumb, so it thinks " 2.40" is not valid syntax for a numeric value. Where am I going wrong w/ my processing of the CSV file? Thanks!

    Read the article

  • Kernel dealing with the section headers in an ELF

    - by uki
    I recently read that the kernel and the dynamic loader mostly deal with the program header tables in an ELF file and that assemblers, compilers and linkers deal with the section header tables. The number of program header tables and section header tables are mentioned in the ELF header in fields named e_phnum and e_shnum respectively. e_phnum is two bytes in size, so if the number of program headers is 65535, we use a scheme known as extended numbering where, e_phnum is set to 0xffff and sh_link field of the zeroth section header table holds the actual count. My doubt is : If the count of program headers exceeds 65535, does that mean the kernel and/or the dynamic loader end up having to read the section table?

    Read the article

  • pthreads recursively calling system command and segfault appears

    - by jess
    I have a code base where i am creating 8 threads and each thread just calls system command to display date in a continuous cycle, as shown below: void * system_thread(void *arg) { int cpu = (int)arg; printf("thread : start %d\n", cpu); for (;;) { // date ã³ãã³ãã®å®è¡ if (mode == 0) { system("date"); } else { f_hfp_nlc_Fsystem("date"); } } sleep(timerval); return NULL; } This application segfaults after running for 2-3 seconds, due to following 2 reasons: 1. read access, where the address is out of VM area 2. write acces, where it does not of write permission and its trying to modify some structure.

    Read the article

  • compiling boost based application using cron

    - by user303544
    Hi All, I am building some boost based application for various embedded targets. I have developed a script which can build my application with different toolchain for several targets. This script works fine when I run it from command line but if it is invoked from cron it always fails to link the object files. My application has dependency on openssl. Can anyone please give some idea? What would be the root cause of this kind of behavior? Thanks in advance.

    Read the article

  • Possible to view PHP code of a website?

    - by Camran
    Is it possible to somehow view another websites php files/codes? Or to rephrase the question, Can my php codes be viewed by anybody except for those who have access to the file? If so, how cant I best prevent this? Thanks Ps: Server OS is Ubuntu 9.10 and PHP version is 5+ (Apache2)

    Read the article

  • measure the response time of a link

    - by Ahoura Ghotbi
    I am trying to create a simple load balance script and I was wondering if it is possible to find the response time of a server live? By that I mean is it possible to measure how long it takes for a server to respond after the request has been sent out? What I am trying to do is fairly simple, I want to send a request to a link/server and do a count down, if the server took more than 5 seconds to reply, I would like to fall on the backup server. Note that it doesnt have to be in pure php, I wouldnt mind using other languages such as javascript, C/C++, asp, but I prefer to do it in PHP. if it is possible to do the task, could you just point me to the right direction so I can read up on it. Clarification What I want to do is not to download a file and see how long it took, my servers have high load and it takes a while for them to respond when you click on a file to download, what I want to do is to measure the time it takes the server to respond (in this situation, its the time it takes the server to respond and allow the user to download the file), and if it takes longer than x seconds, it should fall back on a backup server.

    Read the article

  • C++ class functions calling fortran subroutine

    - by user2863626
    Okay so I am trying to make my code work. It is a simple C++ program with a class "CArray". This class has 2 properties, the array size, and the value. I want the main C++ program to create two instances of the class CArray. In the class CArray, I have a function called "AddArray( CArray )" where it adds another array to the current array. The problem I am stuck with, is that I want the function "AddArray" to add the two arrays in fortran. I know, much more complicated, but that is what I need. I am having issues with linking the two inside the class code. #include <iostream> using namespace std; class CArray { public: CArray(); ~CArray(); int Size; int* Val; void SetSize( int ); void SetValues(); void GetArray(); extern "C" { void Add( int*, int*, int*, int*); void Subtract( int*, int*, int*, int*); void Muliply( int*, int*, int *, int* ); } void AddArray( CArray ); void SubtractArray( CArray ); void MultiplyArray( CArray ); }; Also here is the CArray function file. #include "Array.h" #include <iostream> using namespace std; CArray::CArray() { } CArray::~CArray() { } void CArray::SetSize( int s ) { Size = s; for ( int i=0; i<s; i++ ) { Val = new int[Size]; } } void CArray::SetValues() { for ( int i=0; i<Size; i++ ) { cout << "Element " << i+1 << ": "; cin >> Val[i]; } } void CArray::GetArray() { for ( int i=0; i<Size; i++ ) { cout << Val[i] << " "; } } void CArray::AddArray( CArray a ) { if ( Size == a.Size ) { Add(&Val, &a.Val); } else { cout << "Array dimensions do not agree!" << endl; } } void CArray::SubtractArray( CArray a ) { Subtract( &Val, &a, &Size, &a.Size); GetArray(); } Here is my Fortran code. module SubtractArrays use ico_c_binding implicit none contains subroutine Subtract(a,b,s1,s2) bind(c,name='Subtract') integer s1,s2 integer a(s1),b(s2) if ( s1.eq.s2 ) do i=1,s1 a(i) = a(i) - b(i) end return end end If someone could just help me with setting me up to send arrays of integers from C++ classes to fortran I would greatly appreciate it! Thank you, Josh Derrick

    Read the article

  • boost::this_thread::disable_interruption usage confusion

    - by Evgenii
    boost/thread/pthread/shared_mutex.hpp contains this code: ... #include <boost/thread/detail/thread_interruption.hpp> ... class shared_mutex { ... void lock_shared() { boost::this_thread::disable_interruption do_not_disturb; boost::mutex::scoped_lock lk(state_change); while(state.exclusive || state.exclusive_waiting_blocked) { shared_cond.wait(lk); } ++state.shared_count; } ... }; but boost/thread/detail/thread_interruption.hpp does not contain implementation of disable_interruption, only the prototype. in boost_1_42_0/libs/thread/src/pthread we don't have the implementation too how does it work!???

    Read the article

  • Importing a Mercurial repository automatically (e.g. SVN Externals)

    - by dawmail333
    I have a project that I am developing built off CodeIgniter. The main part of the project is a private system I am creating, but I want to add it to source control, to gain all the associated goodies. Now I'm using Mercurial, so I did the whole hg init bit, so I've got the repository set up. Now, one of the things I've done is to make a library for CodeIgniter, which I use in this project. Now I want to make this library open, so I need a separate repo for that. For anyone unfamiliar with CodeIgniter library development, here's a reference: application /config <- configuration files /libraries <- library logic in here Now I will probably develop a few more libraries in the course of this project, so I can't just dump a repo in the application folder without clumping them all together. What I did was this: dev/ci/library <- library here dev/project <- project here Now in both of those folders, I have made a repository. What I want to do is make the project repository automatically reference the library repository, so I can have a private and a public repository, as I explained earlier. The main way to do this, I have read, is to use subrepositories, but I can only find examples on nested ones (which are unclear anyway, I find). How do I make it reference another repository like svn:externals?

    Read the article

  • how to delete a line from file using awk filtered by some string

    - by embedded
    I have a file delimited by space. I need to write an awk command that receives a host name argument and it should replace the host name if it already defined in the file. It must be a full match not partially - if the file contains this host name: localhost searching for "ho" will fail and it will be added to the end of the file. another option is a delete: again awk receives host name argument and it should remove it from the file if exists. This is what I have so far: (It needs some enhancements) if [ "$DELETE_FLAG" == "" ]; then # In this case the entry should be added or updated # if clause deals with updating an existing entry # END clause deals with adding a new entry awk -F"[ ]" "BEGIN { found = 0;} \ { \ if ($2 == $HOST_NAME) { \ print \"$IP_ADDRESS $HOST_NAME\"; \ found = 1; \ } else { \ print \$0; \ } \ } \ END { \ if (found == 0) { \ print \"$IP_ADDRESS $HOST_NAME\"; } \ } " \ /etc/hosts > /etc/temp_hosts else # Delete an existing entry awk -F'[ ]' '{if($2 != $HOST_NAME) { print $0} }' /etc/hosts > /etc/temp_hosts fi Thanks

    Read the article

  • How to remove strings from a compiled binary (.so)

    - by Stéphane
    How do I remove strings from / obfuscate a compiled binary? The goal is to avoid having people read the names of the functions/methods inside. It is a dynamic library (.so) compiled from C++ code for Android with the NDK tools (includes GCC) I compile with -O3 and already use arm-eabi-gcc -g mylib.so to remove debugging symbols, but when I do strings mylib.so all the names of the functions/methods are still readable.

    Read the article

  • OSError: [Error 1] Operation not permitted

    - by user1357576
    I am trying to run a python script which uses a binary file (xFiles.bin.addr_patched) created by a postlinker. However, I am getting this error. File "abc.py", line 74, in ParseCmd shutil.copy(gOptions.inputX, gWorkingXFile) File "/usr/lib/python2.6/shutil.py", line 89, in copy copymode(src, dst) File "/usr/lib/python2.6/shutil.py", line 66, in copymode os.chmod(dst, mode) OSError: [Errno 1] Operation not permitted: 'myPath/xFiles.bin.addr_patched' When I checked the permissions of this xFiles.bin, by ls-l, it shows that -rwxrwxrwx 1 nobody nogroup I presume the error is because this file was created by some other application, the python script I am running does not have access to it. Since I am beginner wrt ubuntu, I don't really know how to fix it. Any suggestions on how to fix this? SOLVED: As one of the answers Suggested : chown username:groupname file name fixes this issue

    Read the article

  • perf events documentation

    - by Thanatos
    I've searched for an exhaustive explanation of the meaning of each event monitored by the perf stat command; I've found a tutorial which explains quite well how to use different the features of the perf tool. However, it doesn't explain the meaning of several events that can be observed (and there are a lot!!). Someone know where is a quite simple and complete documentation about the events listed by the perf list command? In particular, I'm interested in finding out the percentage of cpu used by some application I wrote. Can i measure it directly through cpu-clock or task-clock? What's the meaning of these two events? Thanks in advance

    Read the article

< Previous Page | 519 520 521 522 523 524 525 526 527 528 529 530  | Next Page >