CSE 220

Use the $ symbol before the variable name

*(p + 1) moves the pointer to the next element in the array and dereferences it, giving the value of the second element.

What operator is used for "greater than" in a shell script when comparing numbers?

-gt

What is the size of sizeof(char) in a 64-bit system?

1 byte

What are the steps in a list comprehension?

1. Iterate over an iterable. 2. Apply an optional condition to filter items. 3. Apply an expression to each filtered item.

What will be printed by the printf statement in the main function? #include <stdio.h> void modifyArray(int arr[], int size) { for (int i = 0; i < size; i++) { arr[i] *= 2; } } int main() { int nums[] = {1, 2, 3, 4}; modifyArray(nums, 4); for (int i = 0; i < 4; i++) { printf("%d ", nums[i]); } return 0; }

2 4 6 8

What is the size of sizeof(int32_t) in a 64-bit system?

4 bytes

What is the size of sizeof(int*) in a 64-bit system?

8 bytes

How can a Python function return multiple values?

A Python function can return multiple values as a tuple: def func(): return 1, 2, 3 # Returns a tuple (1, 2, 3)

What is the base case in recursion?

A condition that must be met in order for the recursion to end.

What is the purpose of a constructor in C++?

A constructor initializes the members of a class when an object is created.

What is a singly linked list in C?

A data structure where each node contains: > Data > A pointer to the next node in the list. The last node points to NULL

What is a function prototype in C?

A function prototype is a declaration of a function that provides its return type, name, and parameters, allowing the function to be called before it is defined.

What is a target in a Makefile?

A target is the name of the file or rule that make builds. It is followed by a list of dependencies and commands to execute.

In a makefile, what is a target that depends on .o files?

A target like $(BIN)/simpleprog depends on object files (.o files) such as $(OBJ)/simpleprog.o and $(OBJ)/progtools.o.

Is printf() a C standard library function or direct system call?

C standard library function. While it eventually calls system functions (such as write()), it's considered part of the standard library, not the kernel's system calls.

What tools are invoked by the command gcc filename.c?

Compiler Linker

What is a System Call?

Direct interaction with the kernel (e.g., fork(), open(), kill())

What will be printed by the printf statement? #include <stdio.h> #include <string.h> int main() { char str1[] = "Hello"; char str2[20]; strcpy(str2, str1); strcat(str2, " World!"); printf("%s\n", str2); return 0; }

Hello World!

What is a Library Function?

Higher-level function that may use system calls (e.g., printf() uses write()).

What is a shell?

Interface that allows users to issue commands

What happens if you don't free memory allocated with malloc()?

It can cause a memory leak, where the allocated memory remains occupied and unavailable for further use until the program exits.

What does if [ -d "dirname" ] check in a bash script?

It checks if the specified path is a directory.

What are the three main components of an operating system?

Kernel, Shell, Device Drivers

What is a kernel?

Manages system resources (CPU, memory, devices).

What is the purpose of .o files in a Makefile?

Object files (.o files) are the result of compiling .c files. They are later linked together to form an executable.

What do the permissions -rw-r--r-- mean for a file?

Owner: read and write Group: read-only Others: read-only

What are private members in a C++ class?

Private members can only be accessed by member functions of the class.

What are device drivers?

Software that enables communication with hardware components.

What is the purpose of templates in C++?

Templates allow functions or classes to operate with any data type, making code reusable and type-independent.

What happens when you pass an array to a function in C?

The array decays into a pointer to its first element, allowing the function to modify the original array.

In the file permissions string, what does the first character represent?

The first character represents the file type: - for a regular file d for a directory

What does the fopen function do in C?

The fopen function opens a file for reading, writing, or appending. It returns a pointer to the file or NULL if the operation fails.

How can a function modify the elements of an array passed to it in C?

The function can use the pointer received (e.g., arr[i]) to directly modify the elements of the original array.

What is the purpose of the shebang line (#!/usr/bin/env bash) in a shell script?

The shebang line specifies which interpreter (e.g., Bash) should be used to run the script.

How do you traverse a singly linked list in C?

Use a loop that starts at the head node and follows each next pointer until NULL is reached.

How do you write a string to a file in C?

Use fprintf with the file pointer: fprintf(file, "Your string here");

How do you check if a file exists in a bash script?

Use if [ -f "filename" ] to check if a regular file exists.

How do you access parameters passed to a function in bash?

Use positional variables: > $1 for the first parameter > $2 for the second parameter, and so on.

How do you correctly reference a variable inside a shell script?

Use the $ symbol before the variable name

What does the compiler do?

___ the source code into object code.

What does the linker do?

____ the object code with libraries to produce the final executable.

What is fork()

a system call used to create a new process. It creates a copy of the calling process, which makes it a core system-level operation.

How do you make a file executable without changing its read or write permissions?

chmod +x filename

How do you make a shell script executable?

chmod +x script.sh

How to remove read permissions from a file

chmod -r script.s

Which command changes the permissions of a file so that anyone can execute it?

chmod 777 file

What is the syntax for a for loop with arithmetic in bash?

for (( i=1; i<=5; i++ )) do echo $i done

What is the correct syntax for a for loop in a shell script to print numbers from 1 to 5?

for i in 1 2 3 4 5 do echo $i done

What is the syntax for defining a function in bash?

function_name() { commands }

In which stage of a compiler is syntax analysis usually done?

in the front end of the compiler.

Which command shows the directory tree and its contents?

ls -R recursively lists the contents of all directories and subdirectories.

What is the correct way to pass a variable to scanf to store user input?

scanf("%d", &guess);

What does the strcat function do in C?

strcat(destination, source) appends the source string to the destination string.

What does the strcpy function do in C?

strcpy(destination, source) copies the contents of the source string into the destination string.

How do you initialize a struct in C?

struct Point p1 = {3, 4};

How do you perform arithmetic operations in bash?

sum=$((sum + i))

How do you define a template function in C++?

template <typename T> T function_name(T param1, T param2) { // function body }

What is a base case in a recursive function?

the condition that stops the recursion

How do you assign a literal string to a variable in bash?

variable="string"

How do you store the output of a command into a variable in bash?

variable=$(command)

How do you add an element to the end of a vector in C++?

vector.push_back(value);

What is structure padding in C?

when the compiler adds extra bytes between structure members to align data in memory for better performance.