This document discusses file handling in C++. It defines a file as a collection of related data stored in a particular area on a disk. It describes why files are used to permanently store data for future use or transfer between computers. It discusses the different stream classes like fstream, ifstream and ofstream used for file input/output. It explains how to open, close and manipulate file pointers to read and write data from files using functions like open(), close(), read(), write(), seekg() and tellg(). It provides an example program that demonstrates writing student data to a file and reading from it based on roll number.
Apache Scoop - Import with Append mode and Last Modified mode Rupak Roy
Familiar with scoop advanced functions like import with append and last modified mode.
Let me know if anything is required. Happy to help.
Ping me google #bobrupakroy.
This project is a classification and analysis of unstructured data and also has the power to classify the different type of data like text, jpg, pdf, doc, png, py, c, c++. java, exe and many more from a single folder.
Presented by Robert Muir and Michael Mccandless, Lucid,IBM - See conference video - http://www.lucidimagination.com/devzone/events/conferences/lucene-revolution-2012
Finite-state technology, including automata and weighted finite state transducers (wFSTs), are compact data structures well suited to text processing and searching applications. Low level support for both automata and wFSTs is now available in Lucene and has recently enabled a number of surprisingly powerful improvements.In this joint talk, Robert Muir and Michael McCandless will provide an overview of finite-state technology and then describe how it's used today in Lucene: synonym filtering, fuzzy queries, respelling/suggesting, terms dictionary, in-memory postings format (MemoryPostingsFormat) and Japanese analysis (Kuromoji analyzer).
Presented by David Smiley, Software Systems Engineer, Lead, MITRE
OpenSextant is an unstructured-text geotagger. A core component of OpenSextant is a general-purpose text tagger that scans a text document for matching multi-word based substrings from a large dictionary. Harnessing the power of Lucene’s state-of-the-art finite state transducer (FST) technology, the text tagger was able to save over 40x the amount of memory estimated for a leading in-memory alternative. Lucene’s FSTs are elusive due to their technical complexity but overcoming the learning curve can pay off handsomely.
A compact bytecode format for JavaScriptCoreTadeu Zagallo
JavaScriptCore (JSC) is the multi-tiered JavaScript virtual machine in WebKit. The bytecode is a central piece in JSC: it’s executed by the interpreter and the source of truth for all of JSC’s compilers. In this talk we’ll look at the recent redesign of our bytecode format, which cut its size in half and enabled persisting the bytecode on disk without impacting the overall performance of the system.
File Handling is used in C language for store a data permanently in computer.
Using file handling you can store your data in Hard disk.
http://www.tutorial4us.com/cprogramming/c-file-handling
Apache Scoop - Import with Append mode and Last Modified mode Rupak Roy
Familiar with scoop advanced functions like import with append and last modified mode.
Let me know if anything is required. Happy to help.
Ping me google #bobrupakroy.
This project is a classification and analysis of unstructured data and also has the power to classify the different type of data like text, jpg, pdf, doc, png, py, c, c++. java, exe and many more from a single folder.
Presented by Robert Muir and Michael Mccandless, Lucid,IBM - See conference video - http://www.lucidimagination.com/devzone/events/conferences/lucene-revolution-2012
Finite-state technology, including automata and weighted finite state transducers (wFSTs), are compact data structures well suited to text processing and searching applications. Low level support for both automata and wFSTs is now available in Lucene and has recently enabled a number of surprisingly powerful improvements.In this joint talk, Robert Muir and Michael McCandless will provide an overview of finite-state technology and then describe how it's used today in Lucene: synonym filtering, fuzzy queries, respelling/suggesting, terms dictionary, in-memory postings format (MemoryPostingsFormat) and Japanese analysis (Kuromoji analyzer).
Presented by David Smiley, Software Systems Engineer, Lead, MITRE
OpenSextant is an unstructured-text geotagger. A core component of OpenSextant is a general-purpose text tagger that scans a text document for matching multi-word based substrings from a large dictionary. Harnessing the power of Lucene’s state-of-the-art finite state transducer (FST) technology, the text tagger was able to save over 40x the amount of memory estimated for a leading in-memory alternative. Lucene’s FSTs are elusive due to their technical complexity but overcoming the learning curve can pay off handsomely.
A compact bytecode format for JavaScriptCoreTadeu Zagallo
JavaScriptCore (JSC) is the multi-tiered JavaScript virtual machine in WebKit. The bytecode is a central piece in JSC: it’s executed by the interpreter and the source of truth for all of JSC’s compilers. In this talk we’ll look at the recent redesign of our bytecode format, which cut its size in half and enabled persisting the bytecode on disk without impacting the overall performance of the system.
File Handling is used in C language for store a data permanently in computer.
Using file handling you can store your data in Hard disk.
http://www.tutorial4us.com/cprogramming/c-file-handling
This is ppt prsented by me in class in this ppt i include file handling in which i tell us about the types of files
creation of text file in C ++ ,updating a text file in C++ , printing the inforamtion in text file .creation of binary file in C ++ ,updating a binary file in C++ , printing the inforamtion in binary file, text file function and binary file function in c++ , File ponters ,syntax of every thing and use of file pointers and many more.
2. FileFile
A file is a collection of related data stored
in
a particular area on the disk . The data is
stored in disk using the concept of file .
File Handling in C++
muzammal sadiq
3. Why FileWhy File
Permanent storage of data : - (all the message or
value printed with help of any output statements like
cout , putchar are never available for future use ) .
If there is a large amount of data generated as
output by a program, storing that output in file will
help in easy handling /analysis of the output , as user
can see the whole output at any time even after
complete execution of the program.
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4. If we need lot of data to be inputted, user cannot
keep on typing that again and again for repeated
execution of program. In that case, all input data can
be once written in a file and then that file can be
easily used as the input file.
The transfer of input – data or output – data from
one computer to another can be easily done by
using files.
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5. Stream classesStream classes
Filebuf :- its purpose is to set the file buffer to read and
write . Contain openprot constant used in the open()
of file stream classes . Also contain close() and open()
as method.
Fstreambase :- provides operations common to the file
stream. Serves as a base for fstream, ifstream and
ofsteram class. Contains open() and close() function
Ifstream :- provides input operations. Contains open()
with default input mode. Inherits the functions get(),
getline(), read(), seekg() and tellg() function from
istream.
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6. Ofstream :- provides output operations. Contains
open() with default output mode. Inherits put(),
seekp(), teelp() and write() function from
ostream.
Fstream :- provides support for simultaneous input
and output operations. Contains open() with default
input mode. Inherits all the function from isteram
and ostream classes through iostream
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7. Opening file using open()Opening file using open()
The function open() can be used to open
multiple files that use the same stream object.
file-stream-class stream-object;
stream-object . open (“filename”);
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8. Open and close a fileOpen and close a file
eg:-
ofstream outfile; // create stream
outfile . open (“DATA1”); // connect stream to DATA1
……………………………..
……………………………..
outfile . Close(); //disconnect stream from DATA1
outfile . Open(“DATA2”); //connect stream to DATA2
……………………………..
……………………………..
outfile . close();
……………………………..
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9. Mode of file openingMode of file opening
ios :: out = open file for write only
ios :: in = open file for read only
ios :: app = append to end-of-file
ios :: ate = take us to the end of the file when it
is opened
Both ios :: app and ios :: ate take us to the end of the file
when it is opened. The difference between the two
parameters is that the ios :: app allows us to add data to
the end of file only, while ios :: ate mode permits us to
add
data or to modify the existing data any where in the file.
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10. The mode can combine two or more parameters
using the bitwise OR operator (symbol |)
eg :-
fstream file;
file . Open(“ data . txt”, ios :: out | ios :: in);
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11. File pointerFile pointer
Each file have two associated pointers known as
the file pointers. One of them is called the input
pointer (or get pointer) and the other is called the
output pointer (or put pointer). The input pointer
is used for reading the contents of a given file
location and the output pointer is used for writing
to a given file location.
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12. Function for manipulationFunction for manipulation
of file pointerof file pointer
When we want to move file pointer to desired
position then use these function for manage the
file pointers.
Seekg () = moves get pointer (input) to a
specified location
Seekp () = moves put pointer (output) to a
specified location
tellg () = gives the current position of the get pointer
tellp () = gives the current position of the put pointer
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13. fout . seekg(0, ios :: beg) -- go to start
fout . seekg(0, ios :: cur) -- stay at current position
fout . seekg(0, ios :: end) -- go to the end of file
fout . seekg(m, ios :: beg) -- move to m+1 byte in the file
fout . seekg(m, ios :: cur) -- go forward by m bytes from
the current position
fout . seekg(-m, ios :: cur) -- go backward by m bytes
from the current position
fout . seekg(-m, ios :: end) -- go backward by m bytes
from the end
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14. put() and get() functionput() and get() function
The function put() write a single character to the
associated stream. Similarly, the function get()
reads a single character from the associated
stream.
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15. read() and write() functionread() and write() function
file . read ((char *)&V , sizeof (V));
file . Write ((char *)&V , sizeof (V));
These function take two arguments. The first is
the address of the variable V , and the second is
the length of that variable in bytes . The address
of variable must be cast to type char * (i.e pointer
to character type) .
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16. Program for file handlingProgram for file handling
#include< iostream . h>
#include< conio .h>
#include< fstream . h>
Class student
{
Public:
Struct stu
{
char name[20];
int roll;
}s;
Void put_data();
Void get_data();
};
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17. void student :: put_data()
{
cout<<"enter name ";
cin>>s. name;
cout<<"enter roll ";
cin>>s. roll;
file. Open ("hit. txt“ , ios :: out | ios :: app);
file. write ((char *)this, sizeof (student));
file. close();
getch();
get_data();
}
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18. void student :: get_data()
{
int temp;
cout<<"enter roll no. ";
cin >>temp;
fstream file;
file. open ("hit . txt", ios :: in);
file.seekg(0,ios::beg);
While (file . read ((char *) this, sizeof (student)))
{
If (temp==s. roll)
{
cout<<"student name "<< s . name<<"n";
cout<<"student roll "<< s . roll;
}
}
getch ();
}
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