File Handling in C

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File Handling in C
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File Handling

• Introduction to File Handling
• Data entered once, required later again
• Same Data to be used by others
• Data required again by the same program
• Files and Streams

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Program
Output Stream
Input Stream
Files
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I/O Streams

• Stream Description
• cin Standard input stream
• cout Standard output stream
• cerr Standard error stream

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File i/o Streams

• Stream Classes required for File i/o
• ifstream
• ofstream
• fstream

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ifstream

• Input file stream Class
• open() is a member function of the class ifstream
• Inherited functions of ifstream class, from the
  class istream are
• get()
• getline()
• read()
• seekg()
• tellg()

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ofstream

• Output file stream Class
• open() is a member function of the class ofstream
• Inherited functions of ofstream class, from the
  class ostream are
• put()
• write()
• seekp()
• tellp()

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fstream

• It supports files for simultaneous input and
  output
• fstream is derived from
• ifstream
• ofstream
• iostream
• They are parent classes and fstream is the child
  class

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fstream

• Member functions of the class fstream
• open
• close
• close all
• seekg
• seekp
• tellg
• tellp

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• //This program creates a file called
  message.dat
• include ltfstreamgt //Required for file I/O
• include ltiostreamgt
• using namespace std
• int main()
• ofstream myfile ("message.dat")
• if (!myfile)
• //check if the file is opened or not
• coutltlt"\n Cannot open this file"
• return 1
• myfile ltlt"When an apple fell, Newton was
  disturbed \n"
• myfile ltlt"but, when he found that all apples
  fell, \n"
• myfile ltlt"it was gravitation that attracts them
  down,\n"
• myfile ltlt"he was satisfied \n"
• myfile.close() //close the file

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Function in C

• Function Prototype
• Function Call
• Function Definition