Free Test File operations fopen – C Language

Q1: What does the fopen() function do?

A. Opens a file and returns a file pointer B. Closes a file C. Reads from a file D. Writes to a file

Q2: What does fopen("file.txt", "r") do?

A. Opens file.txt for reading B. Opens file.txt for writing C. Creates file.txt D. Deletes file.txt

Q3: What happens if fopen() fails to open a file?

A. Returns NULL B. Throws exception C. Returns -1 D. Exits program

Q4: Which mode opens a file for appending data?

A. "a" B. "w" C. "r" D. "rb"

Q5: How to open a binary file for reading using fopen?

A. fopen("file.bin", "rb") B. fopen("file.bin", "r") C. fopen("file.bin", "wb") D. fopen("file.bin", "ab")

Q6: What is the return type of fopen()?

A. FILE * B. int C. void * D. char *

Q7: Which of these is NOT a valid fopen mode?

A. "rw" B. "r+" C. "w+" D. "a+"

Q8: How do you check if fopen() was successful?

A. Check if returned pointer is not NULL B. Check if returned pointer is 0 C. Check if it returns 1 D. Use errno

Q9: What happens if fopen() is called with mode "w" on an existing file?

A. File is truncated (emptied) B. File is appended C. File is read-only D. File remains unchanged

Q10: Which header file is needed for fopen()?

A. <stdio.h> B. <stdlib.h> C. <string.h> D. <fcntl.h>

Q11: Can fopen() open files on network drives?

A. Yes, if path is accessible B. No C. Only local files D. Only with special flags

Q12: What does mode "r+" signify in fopen()?

A. Open for reading and writing B. Open for reading only C. Open for writing only D. Open for appending

Q13: Which mode creates a new file or truncates existing file?

A. "w" B. "a" C. "r" D. "r+"

Q14: What happens if fopen() is used with a non-existing file in "r" mode?

A. Returns NULL B. Creates new file C. Truncates file D. Throws error

Q15: Can fopen() be used to open directories?

A. No B. Yes C. Only on Windows D. Only with specific flags

Q16: What is the effect of using "a+" mode in fopen()?

A. Open file for reading and appending B. Open file for reading and writing C. Only append data D. Only read data

Q17: Is it necessary to close a file opened with fopen()?

A. Yes, using fclose() B. No, system closes automatically C. Only for write mode D. Only for read mode

Q18: Which function is used to close a file opened with fopen()?

A. fclose() B. close() C. fileclose() D. endfile()

Q19: Can fopen() open files with relative paths?

A. Yes B. No C. Only absolute paths D. Only if path is in working directory

Q20: What does the mode "wb" do in fopen()?

A. Open a file for writing in binary mode B. Write and append C. Read binary D. Write text

Q21: What does the fopen() function do?