FileTutorial.d


/*

 * This is a short tutorial on the file creation system

 * for the D programming language.

 *

 */

importstd.stream;

voidmain()

{

inta=int.sizeof;

longb=long.sizeof;

//Create a File stream.

FilefirstFile=newFile;



//Creates the file with the name Foo.txt.1

firstFile.create("Foo.txt");

printf("The file Foo.txt has been created\n");



//Now lets write some stuff to the file.

firstFile.writeString("This writes a string to the file. ");

firstFile.writeString("Notice that this will write to the same line. ");

firstFile.writeLine("This will continue to be on the same line. ");

firstFile.writeLine("However, this will be on a new line. ");



firstFile.writeString("The size of an integer is: ");

firstFile.write(a);

firstFile.writeLine("");

firstFile.writeString("The size of a long is: ");

firstFile.write(b);

firstFile.writeLine("");

printf("%d%ld\n",a,b);



printf("Closing the file\n");



//Destructor should close a file if its still open, 

//but it is best to close the file manually anyway.

firstFile.close();



//Create a new File stream and give it

//a name of a file to open in read only mode.

try{

FilenewFile=newFile("Foo.txt");

printf("The first line of the file we just created is: \n %.*s\n",newFile.readLine());



//Skips over 10 character from current position.

newFile.seek(10,SeekPos.Current);



//print out the next 5 characters in the file.

printf("The next 5 characters are: %.*s\n",newFile.readString(5));



//fileStreamName.position tells where in the File stream you are currently at.

printf("We are currently at %d in the file \n",newFile.position);



//We can also adjust our position in the file by using position(ulong).

//We can seek from the end of the file using seekEnd(long offset), and from the

//begining using seekSet(long offset)

newFile.position(newFile.seekEnd(-20));

printf("Print the last 20 characters in the file: %.*s\n",newFile.readString(20));



//one last operation is copying from one file to another.

FilecopyFile=newFile;

copyFile.create("FooCopy.txt");

copyFile.copyFrom(newFile);



//You can also copy small segments of data from one file to another.

//The second parameter is a uint of the number of bytes to copy from the first stream.

//Currently not correctly implemented

copyFile.copyFrom(newFile,130);



//Again, close any streams after opening.

copyFile.close();

newFile.close();

}catch(OpenExceptione)//Catches the exception if the file was not there.

{

printf("Sorry, the file was not found");

return;

}

}