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std::basic_istream::read

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< cpp‎ | io‎ | basic istream
 
 
Biblioteca de E/S
Manipuladores de E/S
E/S estilo C
Búfers
(en desuso en C++98)
Flujos
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E/S de archivos
E/S de cadenas
E/S de arrays
(en desuso en C++98)
(en desuso en C++98)
(en desuso en C++98)
Salida sincronizada
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(C++11)
 
std::basic_istream
Los objetos globales
Original:
Global objects
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Las funciones miembro
Original:
Member functions
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Entrada con formato
Original:
Formatted input
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Entrada sin formato
Original:
Unformatted input
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basic_istream::read
Posicionamiento
Original:
Positioning
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Varios
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Miscellaneous
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Clases de miembros
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Member classes
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Terceros funciones
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Non-member functions
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basic_istream& read( char_type* s, std::streamsize count );
Extrae caracteres de corriente .
Original:
Extracts characters from stream.
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Se comporta como UnformattedInputFunction. Después de la construcción y comprobación del objeto centinela, extrae los caracteres y los almacena en posiciones sucesivas de la matriz de caracteres cuyo primer elemento es apuntado por s. Los caracteres se extraen y se almacenan hasta que cualquiera de las condiciones siguientes:
Original:
Behaves as UnformattedInputFunction. After constructing and checking the sentry object, extracts characters and stores them into successive locations of the character array whose first element is pointed to by s. Characters are extracted and stored until any of the following conditions occurs:
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  • count caracteres se extraen y se almacenan
    Original:
    count characters were extracted and stored
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  • condición de fin de archivo se produce en la secuencia de entrada (en cuyo caso, se llama setstate(failbit|eofbit) .
    Original:
    end of file condition occurs on the input sequence (in which case, setstate(failbit|eofbit) is called.
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Contenido

[editar] Parámetros

s -
puntero a la matriz de caracteres para almacenar los caracteres a
Original:
pointer to the character array to store the characters to
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count -
número de caracteres a leer
Original:
number of characters to read
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[editar] Valor de retorno

*this

[editar] Ejemplo

leer () se utiliza a menudo para binarios I / O
Original:
read() is often used for binary I/O
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#include <iostream>
#include <string>
#include <sstream>
#include <cstdint>
int main()
{
    std::string bin = {'\x12', '\x12', '\x12', '\x12'};
    std::istringstream raw(bin);
    std::uint32_t n;
    raw.read(reinterpret_cast<char*>(&n), 4);
    std::cout << std::hex << std::showbase << n << '\n';
}

Salida:

0x12121212

[editar] Ver también

inserciones de bloques de caracteres
Original:
inserts blocks of characters
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(función miembro pública de std::basic_ostream) [editar]
extraer datos con formato
(función miembro pública) [editar]
extrae los bloques que ya están disponibles los personajes
Original:
extracts already available blocks of characters
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(función miembro pública) [editar]
extractos personajes
Original:
extracts characters
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(función miembro pública) [editar]
extractos de caracteres hasta el carácter determinado se encuentra
Original:
extracts characters until the given character is found
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(función miembro pública) [editar]
lee un archivo
Original:
reads from a file
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(función) [editar]