Read words in a file in reverse order

Consider a file that contains the following text,

            Brand New World

The result after reading the words in the reverse order

         World New Brand

Steps to be performed:

1.      Open a file and move the pointer to the end of the file.

2.      Move the pointer to the current-1 position

3.      Read the character and store it in an array.

4.      Move the pointer to the current-2 position and read the character and store it in an array.

5.      If the character is a blank space, then reverse the array. To reverse array use 'fliplr'.

6.      Append the array to a string and initialize the array to zero.

7.      Repeat this procedure till the pointer reaches the beginning of the file.

8.      To learn more about file reverse: http://angeljohnsy.blogspot.in/2012/10/read-file-in-reverse-from-end-of-file.html

MATLAB CODE:

%Open a file to read

fp=fopen('rev.txt');

%Move the pointer to the end of the file

fseek(fp,0,'eof');

%Find the position

fsz=ftell(fp);

n=1;

%Move the pointer to the current-1 position

fseek(fp,-1,'cof');

%Read a character

c=fread(fp,1,'*char');

%Store in the matrix

M(1,n)=c;

Words=0;

%Check whether the file pointer has reached the beginning of the file

    while(fseek(fp,-2,'cof')~=-1)

       

        c=fread(fp,1,'*char');

        %When a space is encountered reverse the character array and append

        %it to a string

        if(isspace(c))

              if(Words==0)

                  %Intially, the string is empty.

                  %Append the array in the reverse order with a blank space

                   Words=[fliplr(M) blanks(1)];

              else

                  %Append the reversed character array to the string

                   Words=[Words fliplr(M)];

              end

           n=1;

           M='';

        else

            %The array is updated with the characters until blank space is

            %encountered

           n=n+1;

           M(1,n)=c;

          

        end

    end

   

Words=[Words fliplr(M)];

display(Words);

fclose(fp);

Result:

Words =

World New Brand