File Handling Basics in C: Multiple Choice Quiz Quiz

This quiz covers essential file handling concepts in C programming, including file operations, functions, modes, and error handling. Strengthen your understanding of how to read from, write to, and manage files efficiently in C with these beginner-level questions.

1. Identifying the Standard File Opening Function

   Which function is most commonly used to open a file for reading or writing in C?

   1. openfile
   2. fileopen
   3. fscan
   4. fopen

   Explanation: The 'fopen' function is the standard way to open a file in C, allowing you to specify the file name and mode. 'fscan' is not a valid C function; 'fileopen' and 'openfile' also do not exist in the language. Only 'fopen' is recognized by C compilers for this purpose, making it the correct choice here.

2. Choosing the Mode for Writing a New File

   If you want to create a new file or overwrite an existing one with fresh content, which mode should you use with fopen()?

   1. w
   2. r
   3. rw
   4. a

   Explanation: Opening a file in 'w' mode means write mode, which creates a new file or overwrites the existing file's content if it already exists. The 'r' mode is for reading only and will not create a file. The 'a' mode is for appending, and 'rw' is not a valid mode in standard C. Therefore, 'w' is the best choice for this scenario.

3. Understanding File Closure

   Which function should you call to properly close a file that was opened with fopen()?

   1. fclose
   2. endfile
   3. fileclose
   4. closef

   Explanation: 'fclose' is the correct function to close an open file and release associated resources in C. The other options, such as 'closef', 'fileclose', and 'endfile', are not standard C functions. Using 'fclose' is essential for proper file handling and data integrity.

4. Detecting End of File

   Which function can be used to check if the end-of-file indicator associated with a file stream is set?

   1. eoffile
   2. fileeof
   3. eofcheck
   4. feof

   Explanation: 'feof' checks if the end-of-file indicator is set for a given file stream. The options 'eoffile', 'fileeof', and 'eofcheck' are not valid functions in C for this purpose. Only 'feof' is part of the standard library for detecting end-of-file conditions.

5. Reading a Character from a File

   If you want to read a single character from a file in C, which function should you use?

   1. fgetc
   2. fget
   3. getcfile
   4. getfilec

   Explanation: 'fgetc' is designed to read a single character from a specified file stream. The alternatives, such as 'fget', 'getcfile', and 'getfilec', are not defined in the C standard library. Only 'fgetc' correctly performs the desired operation.

6. Opening a File in Append Mode

   Suppose you want to add text to an existing file without erasing its content. Which mode should you use when opening the file?

   1. r
   2. w
   3. ar
   4. a

   Explanation: Using 'a' for append mode allows you to write data to the end of the file without affecting existing content. The 'w' mode would overwrite the file, 'r' is read-only, and 'ar' is not a standard mode. Therefore, 'a' is the appropriate and only valid option here.

7. String Input from a File

   Which function is typically used to read a string (sequence of characters) from a file in C?

   1. getfstring
   2. fgetsline
   3. filereadstr
   4. fgets

   Explanation: 'fgets' is the standard C function for reading strings (lines) from a file, ensuring safety by specifying the buffer size. The other options, like 'fgetsline', 'getfstring', and 'filereadstr', do not exist in standard C. Only 'fgets' should be used for this purpose.

8. Writing Data to a File

   What function should you use to write formatted data (for example: numbers or text) into a file in C?

   1. filewrite
   2. printf
   3. writefilef
   4. fprintf

   Explanation: 'fprintf' is used in C to write formatted output to a file stream. 'printf' outputs data to the standard output, not to files. The options 'filewrite' and 'writefilef' are not defined in C. Therefore, 'fprintf' is the correct function for formatted file output.

9. Verifying File Was Opened Successfully

   How can you check if fopen() failed to open a file successfully?

   1. Check if the return value is 1
   2. Check if the return value is 0
   3. Check if the return value is NULL
   4. Check if the return value is empty

   Explanation: When fopen() fails, it returns NULL to indicate the file could not be opened. Checking for 0 or 1 does not correctly indicate failure, as fopen() returns a pointer, not a number. An 'empty' return value is not a concept in C. Thus, inspecting for NULL is the correct approach.

10. Moving the File Pointer

    Which function allows you to move the file pointer to a specific position in a file?

    1. moveptr
    2. fseek
    3. setfilep
    4. seekfile

    Explanation: 'fseek' is the standard function to reposition the file pointer within a file stream. 'moveptr', 'seekfile', and 'setfilep' are invalid in C and do not serve this purpose. 'fseek' gives precise control over file access and navigation.