You are developing a log monitoring tool that needs to constantly read a log file and process new entries. What approach would you take to efficiently read the file?
- Employ multi-threading to parallelize log file reading.
- Periodically restart the application to clear the file buffer.
- Use a polling mechanism to check for file changes.
- Use a single-threaded approach to read the file sequentially.
Efficient log file reading often involves multi-threading to process entries concurrently, leading to better performance.
You're developing a program that needs to frequently update specific records in a large binary file. Which file handling functions would be most useful to efficiently locate and update records?
- fseek() and fwrite()
- fread() and ftell()
- fprintf() and fscanf()
- fgetc() and fputc()
To efficiently locate and update records in a binary file, you would use fseek() to move to the desired position and fwrite() to write the updated data. The other options are not suitable for this specific task.
A pointer to a function in C is declared using the syntax ________.
- *func_ptr
- func()ptr
- func_ptr()
- ptr_func
In C, to declare a pointer to a function, you use the syntax "return_type (*pointer_name)(arguments)." This allows you to call a function through the pointer.
Failing to release a memory block with ________ before the program terminates can result in a memory leak.
- calloc()
- free()
- malloc()
- realloc()
Failing to release memory with the "free()" function in C can result in a memory leak, where the allocated memory is not properly deallocated, causing the program to consume more memory than necessary.
Consider a scenario where a program needs to store a character read from a file. Which data type would be appropriate for this?
- char
- double
- float
- int
To store a character read from a file in C, the appropriate data type is 'char' as it can represent individual characters effectively.
What is a potential risk of using the gets() function for reading strings in C?
- It always returns NULL
- It can lead to buffer overflow
- It doesn't exist in C
- It has a higher time complexity
The gets() function is risky because it does not perform bounds checking and can lead to buffer overflows, potentially exposing the program to security vulnerabilities.
You're working on a program that continuously monitors sensor data and reacts when a certain threshold is reached. Which loop construct would be most suitable for this task?
- do-while loop
- for loop
- if-else statement
- while loop
The most suitable loop construct for continuously monitoring sensor data is a 'while loop.' A while loop checks a condition and executes its code block repeatedly as long as the condition is true. This allows continuous monitoring until the threshold is reached.
What is the significance of the size_t return type in the fwrite function?
- It determines the file's size.
- It indicates the file's creation date.
- It is used to specify the file mode.
- It represents the number of items written to the file.
The size_t return type in the fwrite function signifies the number of items successfully written to the file. This is important for checking the success of the write operation.
What is the difference between malloc and calloc in terms of initialization of the allocated memory?
- Calloc initializes memory to an undetermined value.
- Calloc initializes memory to zero.
- Malloc initializes memory to an undetermined value.
- Malloc initializes memory to zero.
Malloc initializes memory to an undetermined value, while calloc initializes memory to zero. This difference is important when you want to ensure that allocated memory is initialized in a specific way.
Which operator is used to check if two values are equal?
- !=
- =
- ==
- ===
In C, the '==' (double equals) operator is used to check if two values are equal. It is a comparison operator, while '=' is an assignment operator. Confusing these can lead to unintended consequences, making it crucial to understand their distinct purposes in programming.