C PROGRAMMING PROGRAM • FUNCTIONS, PREPROCESSOR & COMMAND LINE

Read Command-Line Arguments

Learn how to read command-line arguments using a clear C program.

Intermediateargcargvmain parameters

PROBLEM UNDERSTANDING

Input and expected output

Sample input

No input required

Sample output

No command-line arguments supplied.

COMPLETE C PROGRAM

Complete C implementation

#include <stdio.h>

int main(int argc, char *argv[])
{
    if (argc == 1) {
        puts("No command-line arguments supplied.");
        return 0;
    }
    printf("Argument count = %d\n", argc - 1);
    for (int index = 1; index < argc; index++)
        printf("Argument %d = %s\n", index, argv[index]);
    return 0;
}

CURRENT STEP

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SELECTED LINE

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EXPECTED OUTPUT FOR THE SAMPLE

No command-line arguments supplied.

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Read the required input values.
Use argc for the number of tokens and argv for the string stored at each command-line position.
Display the computed result.

Use argc for the number of tokens and argv for the string stored at each command-line position.

EFFICIENCY

Time and space complexity

Time complexity

O(n)

Auxiliary space

O(1)

DEBUGGING CHECKLIST

Common mistakes

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Use the correct format specifier for every variable.

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Initialize variables before using their values.

Check this

Check braces, semicolons and input order carefully.

Try it yourself

Practice: Run the program with the sample input, predict its output, and then test one boundary case of your own.