Stream input and output functions, C/C++ Programming

Assignment Help:

  Within C we access external devices by means of a pointer i.e. address. The address could point to any memory mapped device i.e. Ram, Rom, Duart, Disk drives etc. Therefore there is no difference between accessing area in Ram or a file on a disk. However accessing devices usually require an initialization program, within C this is achieved by the fopen/fclose commands. The syntax of the fopen command is
 
    void main()
    {    
    FILE *name;
    name = fopen(device or file name , access);
 
    if (name == NULL ) 
    {
      printf("cannot open the file \n\r");
      exit(1);
    }
    }
 
The device or file name is usually machine dependent i.e.
 
    VMS    "dsk$usr:[en_staff.entjmc]file.ext"
    Unix    "dsk$usr:en_staff\entjmc\file.ext"
    Mac    "dskname:folder:folder:file";
    PC    "drive name:\directory\file.ext";
 
By default the current disk and directory are taken if not specified. The access describes the write/read privilege and type of data stored i.e. text or binary. Text is used to describe sequential data while binary is standard random access data
 
    "r"    Text file read only
    "w"    Create a new Text file write only
    "a"    Append to end of the text file
    "rb"    Binary file  read only
    "wb"    Binary file write only
    "ab"    Append to end of the binary file
    "r+"    Text file read and write 
    "w+"    Create a new text file for read and write
    "a+"    Append to end of the text file for read and write 
    "rb+"    Binary file read and write
    "wb+"    Create a binary file for read and write
    "ab+"    Append  to end of the binary file for read and write

For example to create a write access file called out.txt we use
 
    name = fopen("out.txt","w");
 
  i.e   file name  = out.txt
    access = create /write text file 
 
It is important to close all channels when finished; this is achieved by fclose i.e.
    
    fclose(name);


Related Discussions:- Stream input and output functions

Explain different access specifiers in a class, Question 1 Create a class ...

Question 1 Create a class String which stores a string value. Overload ++ operator which converts the characters of the string to uppercase (toupper() library function of "ctype.h

Client-server architecture Project, I need a client-server architecture pro...

I need a client-server architecture program for windows OS (minimum support: Win 7),. the agent program will run as a background process and perform certain tasks every X time, and

Area of curve, Write a program to find the area under the curve y = f(x) be...

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b

What is an explicit constructor, A conversion constructor declared with the...

A conversion constructor declared with the explicit keyword. The compiler does not use an explicit constructor to execute an implied conversion of types. Its purpose is reserved ex

Explain the functions strlen ( ), Question 1 Consider you have to find out...

Question 1 Consider you have to find out average marks of 100 students in a class. Write simple program(s) using different iteration statements to accomplish it Question 2 Expla

Explain scope rules and storage classes, Scope Rules and Storage Classes ...

Scope Rules and Storage Classes The storage class verifies the life of a variable in terms of its duration or its scope. There are four storage classes : automatic static

Graphic.h, what is the syntax to get a coloured output.

what is the syntax to get a coloured output.

C pgms, find area under the curve y=f(x) between x=a &y=b integrate y=f(x)

find area under the curve y=f(x) between x=a &y=b integrate y=f(x)

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd