Implement a Simple Shell Command Parser

Question

Problem: Implement a Simple Shell Command Parser. Solve this hands-on electronics task on EWskills.

Accepted Answer

#include 
#include 

// Parse line and print each word (token) on a new line
void parse_shell_input(char *line) {
    int i = 0;
    int in_token = 0;

    while (line[i] != '\0' && line[i] != '
') {
        if (isspace(line[i])) {
            if (in_token) {
                putchar('
'); // End of a word
                in_token = 0;
            }
        } else {
            putchar(line[i]);
            in_token = 1;
        }
        i++;
    }

    if (in_token) {
        putchar('
'); // End last token
    }
}

int main() {
    char line[101];
    fgets(line, sizeof(line), stdin);

    parse_shell_input(line);
    return 0;
}

Why This Matters in Firmware?

CLI or shell parsers are used in bootloaders, diagnostic shells, or debug interfaces
You may not have access to strtok() or dynamic memory
Knowing how to parse space-separated strings builds string handling mastery

Logic Summary

Read characters one by one
Print characters until a space is hit
Print newline when token ends
Skip multiple spaces

103. Implement a Simple Shell Command Parser

Wrong test case