C command-line args: sum argv values with atoi, including argv[0] which converts to 0 if non-numeric. /* myprog.c */ #include <stdio.h> #include <stdlib.h> int main(int argc, char **argv) { int i, j = 0; for (i = 0; i < argc; i++) j = j + atoi(argv[i]); printf("%d ", j); return 0; } Executed as: myprog 1 2 3

Introduction / Context: This C program demonstrates how command-line arguments are received via argc and argv, how atoi parses strings into integers, and why argv[0] does not break the sum even though it is the program name. Understanding iteration over argv and numeric conversion behavior is essential for basic CLI handling.

Given Data / Assumptions:

• Program is invoked as: myprog 1 2 3.
• argc counts all tokens, including program name → argc = 4.
• argv[0] is the program name string "myprog"; argv[1]..argv[3] are "1", "2", "3".
• atoi returns 0 for non-numeric prefixes and normal integers for valid strings.

Concept / Approach: The loop sums atoi(argv[i]) for i = 0..argc-1. atoi("myprog") → 0. atoi("1") → 1, atoi("2") → 2, atoi("3") → 3. Therefore the total is 0 + 1 + 2 + 3 = 6.

Step-by-Step Solution:

Verification / Alternative check: Replacing atoi with strtol would also yield the same sums here; testing with additional non-numeric args also demonstrates atoi returns 0 when no leading digits are present.

Why Other Options Are Wrong:

• 123: Concatenation, not addition; program adds numbers.
• Error: Code is valid and compiles.
• "123": String form; program prints an integer.

Common Pitfalls: Forgetting argv[0] is included; assuming atoi would fail or crash on non-numeric strings; expecting string concatenation instead of arithmetic.

Final Answer: 6