Pequeno Shell Unix em C++.

Compilação:

$ g++ -o shell shell.cpp -O3 -Wall -Wpedantic -std=c++11

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Esconder código-fonte

// g++ -o shell shell.cpp -O3 -Wall -Wpedantic -std=c++11
#include <iostream>
#include <string>
#include <sstream>
#include <vector>

#include <sys/wait.h>
#include <unistd.h>

using namespace std;

vector<string> split_string(const string& input,
                            const char delimiter) 
{
    stringstream ss {input};
    vector<string> result;
    
    for (string buffer; 
         getline(ss, buffer, delimiter);) 
            {result.push_back(move(buffer));}
    
    return result;
}

int launch_execute(const vector<string>& command)
{
    // handle builtins
    if (command.size() == 0) return 1;
    else if (command[0] == "exit") return 0;
    else if (command[0] == "cd") {
        if (command.size() == 1 || command.size() > 2) {
            cerr << "shell: expected 1 argument to \"cd\"\n";
        }
        else {
            if (chdir(command[1].c_str()) != 0) {
                perror("shell");
            }
        }
        
        return 1;
    }
    
    
    // cast vector<string> to const char**
    const char **argv = new const char* [command.size()+1];
    
    for (unsigned j = 0;  j < command.size();  ++j) {
        argv [j] = command[j].c_str();
    }

    argv[command.size()] = NULL;

    // fork
    int status = 0;
    pid_t pid = fork();
    if (pid == 0) {
        // Child process
        if (execvp(argv[0], (char **)argv) == -1) {
            perror("shell");
        }
        delete[] argv;
        exit(EXIT_FAILURE);
        
    } else if (pid < 0) {
        // Error forking
        perror("shell");
        
    } else {
        // Parent process
        do {
            waitpid(pid, &status, WUNTRACED);
        } while (!WIFEXITED(status) && !WIFSIGNALED(status));
    }
    
    delete[] argv;
    return 1;
}


int main()
{
    int status = 0;
    string line = "";
    
    do {
        cout << "shell> ";
        getline(cin, line);
        vector<string> args = split_string(line, ' ');
        
        status = launch_execute(args);
        
    } while (status);
    
    return 0;
}

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