File Handling

This program demonstrates how to write data to a file, read data from a file, and handle file closing in Scilab.

Step 1: Writing to a File

// Open the file for writing ('w')

fileID = fopen('example.txt', 'w');

// Check if the file was opened successfully

if fileID == -1 then

    disp('Error opening file for writing');

else

    // Write some data to the file

    fprintf(fileID, 'This is a test message written to the file.\n');

    fprintf(fileID, 'Scilab file handling example.\n');

    // Close the file

    fclose(fileID);

    disp('Data written to the file successfully.');

end

Step 2: Reading from a File

// Open the file for reading ('r')

fileID = fopen('example.txt', 'r');

// Check if the file was opened successfully

if fileID == -1 then

    disp('Error opening file for reading');

else

    // Read the data from the file line by line

    while %t

        line = fgets(fileID); // Read one line

        if line == -1 then

            break; // End of file

        end

        disp(line); // Display the line

    end

    // Close the file

    fclose(fileID);

    disp('Data read from the file successfully.');

end

Explanation:

• fopen('filename', 'mode'): Opens a file. The mode can be:
  
  

  • 'r' for reading,
    
    

  • 'w' for writing,
    
    

  • 'a' for appending.
    
    

• fprintf(fileID, 'text'): Writes formatted text to the file.
  
  

• fgets(fileID): Reads one line of text from the file.
  
  

• fclose(fileID): Closes the file when you're done with it.
  
  

Error Handling:

• The program checks if the file is opened successfully by verifying the return value of fopen.
  
  

  • If it returns -1, there was an error opening the file.
    
    

  • If the file opens successfully, the operations (writing or reading) are performed.