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Syntax error: Bad fd number when calling function system c++

Mystic last edited by
On call:
```
system("ipfw pipe list >& pipe.lst");
```
Makes a return with a mistake.
Syntax error: Bad fd number
The same team, which has been made directly to the consoles, is performed without error. OS FreeBSD. The result of ipfw pipe list, including stderr, should be recorded in the file
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gionna last edited by
That's right.
```
system("ipfw pipe list &> pipe.lst"); // пишем stdout и stderr
```
Pro http://tldp.org/LDP/abs/html/io-redirection.html details
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When you write a console application, the compiler in the exe heading (in the so-called PE headline) displays a special flashlight that the application is console. After that, when the time comes to start the application, Windows himself will create a terminal emulsion for your application. Like he's in this Windows, it's the OS itself.When you have to make a conclusion to the console, the plus++ compilator for the vindas will just challenge the WriteConsole that can do it. There's no interruption there, and there's no interruption.The other thing is an old 16-bit code that still exists and wants to take something out. Although the files have an exe expansion, the structure is slightly different (there is no re heading but only MZ). Vinda understands it creates a similar terminal, but all interruptions intercept, deal with them and emulate them whenever possible.Therefore, while the code does the same for the user, there are two completely different systems at the internal level.
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Function definition error in C
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int main() { float matrixsuma(float A[i][j], float B[i][j], float C[i][j]); // <<<--- matrixsuma(A, B, C); } The nesting functions are not permitted by the C standard. If it is true that some compiler extensions can activate this feature but it is not the most recommended.By code clarity, the definitions of functions (e.g. not implying that there are ancillary functions) should be outside the main.float matrixsuma(float A[i][j], float B[i][j], float C[i][j]); int main() { matrixsuma(A, B, C); } On the other hand, it is necessary to be very cautious when making use of global variables. The problem that global variables have is that being accessible from the entire application is difficult to control access to the variable, as well as to be problematic in multi-hylo environments.Talking about your problem, the function is undeclared:float matrixsuma(float A[i][j], float B[i][j], float C[i][j]) { } i and j They are not constant data but variables. In the case of multidimensional arrays the compiler needs to know the size of certain dimensions so that access to the elements of such arrays are satisfactory.In the case of drumimiensional arrays the compiler needs to know the size of the second dimension:float matrixsuma(float A[][MAX], float B[][MAX], float C[][MAX]) { } Although if desired, the size of the first dimension can also be put, although, in this case, the data will have no consequences:float matrixsuma(float A[MAX][MAX], float B[MAX][MAX], float C[MAX][MAX]) { } And, well, as a tip, I would tell you that the code that fills the matrix from the user's input should go into an independent function.A greeting.
Error when I remove an element from a list in c++
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Here:else if( evento == 1 ) { delete *it; listaAnimal.erase( it ); } You remove an element from the list. However, according to https://en.cppreference.com/w/cpp/container/list/erase ,References and iterators to the erased elements are invalidated. Other references and iterators are not affected.That, in free translation on my part:References and iterators to deleted elements are invalid. Other references and iterators are not affected.I mean, if you remove an element from the list using a iterator, said iterator Stop being valid.The very function-member erase( ) comes in our help:Return valueIterator following the last removed element.By calling erase( ), this one returns us an iterator to the next valid element of the list (which can be end( )). We can use it instead of the newly invalidated.So, your code should stay.else if( evento == 1 ) { delete *it; it = listaAnimal.erase( it ); continue; }
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Add at the end of the file after the closing brackets:#include "main.moc"
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for (int i = 0; i < SplitPoly.Count - 1; i++) { SplitPoly[i].Next = SplitPoly[i + 1]; SplitPoly[i + 1].Prev = SplitPoly[i]; }
Why does the compilation make a type error [prog.c:7:13: error: ‘z2’ undeclared (first use in this function)]
Software Programming • c language • • jeanid

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'Cause you can tell me what the two lines of your code are in principle:double a, x, y; double z1; z2; z3; z4; How is one of the from the other variables in the first line and how is the second?By the way, you'll be surprised that you're here.denominator = sin(z3) * atan(z4) + 14,8; Compiler just ignores. ,8 - 'cause it's a camera operator. 14.8♪
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Fatal error: Uncaught Error: Call to a member function fetch_all() on bool
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You have a data check problem:in this section of your code: public static function obtener() { global $mysqli; $resultado = $mysqli->query("SELECT id, nombre, grupo FROM estudiantes"); return $resultado->fetch_all(MYSQLI_ASSOC); } I should validate that there is data... it is actually something basic that you should do in all the database queries: public static function obtener() { global $mysqli; if ($resultado = $mysqli->query("SELECT id, nombre, grupo FROM estudiantes")){ if(0 < $resultado->num_rows){ $mysqli->close(); //Importante Cerrar las Conexiones... return $resultado->fetch_all(MYSQLI_ASSOC); }else{ //Control de Error en la respuesta: echo 'no se encontraron datos en la Consulta'; die; } }else{ //Control de Error en el Query: echo 'error en la consulta a la Base de datos'; die; } } In conclusion: you should only make a fetch if you know that data was returned; otherwise you will have mistakes, jumping everywhere when you consult.
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In modern, i.e. C++17, the difference between class and typename There are no templates. However, in earlier standards, the difference was marked when the template (sic!) parameters were used, i.e., when the template is a template type. In this case, use typename before the name of the template was not acceptable.Example of template function f ( only one line should be commented)://template<template<typename> class C> // любой с++ //template<template<class> class C> // любой с++ //template<template<class> typename C> // начиная с c++17 //template<template<typename> typename C> // начиная с c++17 void f() { } In the case of a modern compiler, use the older version of the standard https://wandbox.org/permlink/yhytX2n5wvrPPLcd to read:template template parameter using 'typename' is a C++17 extension [-Wc+17-extensions]The limitation was due to the following definition of syntax when using templates to c+17 (in particular with+11 p.14.1/1):template < template-parameter-list > class ...opt identifieropt template < template-parameter-list > class identifieropt = id-expression There's a clear mention of the word. class♪B c+17 http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/n4687.pdf p.17.1/1):template < template-parameter-list > type-parameter-key ...opt identifieropt template < template-parameter-list > type-parameter-key identifieropt = id-expression Clear class replaced by type-parameter-keywhich is reproduced as follows:type-parameter-key : class typename Thus typename it is possible to use it together class♪
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Fatal error: Uncaught Error: Call to undefined function mb_substr_count()
Software Programming • php apache • • Rossere

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Access your php.ini, search extension=e look at the list of extensions. If there is no one with the name mbstring, the extension should be installed. If the line is commented (if you have ; on the front), she is not activated ... remove the ; and restart Apache
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The base designer always causes the function of the base class. About the second mistake. You don't give a clear base class designer, and the compiler is trying to call a default designer, but he's not here because you overloaded it. That's the compiler who swears he can't find him.
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Qt provides you with your compiled bookstores for a specific catalog of compilers. If you need to work with a different compiler (and the binaries are not compatible with it) then you will have to compile Qt hand with the new compiler (which is a laborious process both by frames and by time)... but it is not impossible.What you can do is review the Qt maintenance tool as there you will find, for the Qt version with which you will work, some msvc-based kits... download one of those compilers and install the corresponding kit as well as the Qt version compiled with that compiler.For example, version 5.9.1 has 64-bit mountings for:msvc 2013msvc 2015msvc 2017Suppose you have (or you can get) the compiler msvc 2015... what you would have to install then is:close QtCreator (important)install the compilerinstall Qt 5.9.1 - PHP msvc2015 64-bit (from maintenance tool)
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Parse error: syntax error, unexpected ';', expecting ')' in C:\xampp\htdocs\clinica\valire.php on line 5
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As the error says: Syntax error, unexpected ';', waiting ')'Parse error: syntax error, unexpected ';', expecting ')'The mistake is telling you that you need to close parenthesis, so you need to check the lines to see where that symbol is missing. $name = remove_junk($db->escape($_POST['name'])); $last = remove_junk($db->escape($_POST['apellido'])); $user = remove_junk($db->escape($_POST['username'])); $iden = remove_junk($db->escape($_POST['ci'])); $phone = remove_junk($db->escape($_POST['te'])); $email = remove_junk($db->escape($_POST['email'])); $address = remove_junk($db->escape($_POST['dire'])); $contra = remove_junk($db->escape($_POST['pass']));
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How's the test phase to get a protobus?Decision♪ before_script in temple with anchors or job-templates:.protobuf: before_script: - apt-get -y install libprotobuf-dev protobuf-compiler build: extends: .protobuf stage: build script: - ./scripts/build_pb.sh - mkdir build && cd build - cmake .. - cmake --build . - ctest --extra-verbose artifacts: paths: - build/bin/release/server test: extends: .protobuf stage: test script: - build/bin/release/server # запуск сервера - src/py_tests/server_tests.py # запуск тестов Detailed documentation on gitlab anchors: https://docs.gitlab.com/ee/ci/yaml/#anchors
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Software Programming • c++ exceptions • • guilherme

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std::invalid_argument for this task, only on its own.If another heir comes up std::exception, starting with C++11 in std::map method https://en.cppreference.com/w/cpp/container/map/at who's looking for a key and throwing away std::out_of_range♪ Unlike find() He's not returning the terator, but the meaning.
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Method of assessing the probability of N grams
Software Programming • java c++ masses math • • Trenton

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Well, here's an example, maybe it'll be easier.Let's say you have a sequence of zeros and units:X = 1 0 0 0 1 0 0 0 and N = 4. Then we have four sequences:X = 1 0 0 0 1 0 0 0 [1 0 0 0] [0 0 0 1] [0 0 1 0] [0 1 0 0] [1 0 0 0] The probability of this formula is that:p([1 0 0 0]) = 2 / 5 = 0.4 p([0 0 0 1]) = 1 / 5 = 0.2 p([0 0 1 0]) = 1 / 5 = 0.2 p([0 1 0 0]) = 1 / 5 = 0.2 Next, we need to figure out the odds for some sequence. [y1 y2 y3 y4]♪ If [y1 y2 y3 y4] We're on our list, we've got a chance of being counted (e.g. if) [y1 y2 y3 y4] = [0 0 0 1]the probability is 0.2). If not, it's likely to be 0.

Syntax error: Bad fd number when calling function system c++

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