fixed rediriction and appending stdout and stderr on linux, still need to test on windows

include/shellUtils.h

@@ -6,6 +6,7 @@
 #include <cstdlib>
 #include <filesystem>
 #include <vector>
+#include <optional>
 
 namespace sh
 {
@@ -39,9 +40,15 @@ namespace sh
 
     std::optional<std::filesystem::path> isExec(const std::string& input);
 
-    void printType(const std::string& input);
+    void printType(const std::string& input, const std::optional<std::filesystem::path>& stdoutFilePath = std::nullopt);
 
     std::filesystem::path getWorkingDir();
 
-    void changeDir(const std::vector<std::string>& tokens);
-}
+    void changeDir(const std::vector<std::string>& tokens, const std::optional<std::filesystem::path>& stdoutFilePath = std::nullopt);
+
+    void printCommandStdout(std::string_view input, const std::optional<std::filesystem::path>& outputFilePath = std::nullopt, bool append = false);
+
+    void printCommandStderr(std::string_view input, const std::optional<std::filesystem::path>& outputFilePath = std::nullopt, bool append = false);
+
+    void executeCommand(const std::filesystem::path& exePath, const std::vector<std::string>& tokens, const std::optional<std::filesystem::path>& stdoutFilePath = std::nullopt, const std::optional<std::filesystem::path>& stderrFilePath = std::nullopt, bool appendStdout = false, bool appendStderr = false);
+}

src/main.cpp

@@ -1,16 +1,11 @@
 #include <iostream>
 #include <string>
-#include <map>
 #include <cstdlib>
 #include <filesystem>
+#include <fstream>
 #include <vector>
+#include <optional>
 
-#ifdef _WIN32
-#include <process.h>
-#else
-#include <unistd.h>
-#include <sys/wait.h>
-#endif
 
 #include "shellUtils.h"
 
@@ -25,6 +20,10 @@ int main()
   while (!shouldExit)
   {
     tokens.clear();
+    std::optional<std::filesystem::path> stdoutFile;
+    std::optional<std::filesystem::path> stderrFile;
+    bool appendStdout{false};
+    bool appendStderr{false};
 
     std::string input;
     std::string line;
@@ -34,6 +33,12 @@ int main()
 
     while (!finshedInput and std::getline(std::cin, line))
     {
+      if (line.empty())
+      {
+        finshedInput = true;
+        continue;
+      }
+
       auto end = line.size() - 1;
       if (line[end] == '\\')
       {
@@ -74,7 +79,69 @@ int main()
     //we can now assume there is actual text from the input
     sh::tokenize(tokens, input);
 
+    //check for redirection
+    for (size_t i = 0; i < tokens.size();)
+    {
+      if (tokens[i] == ">>" or tokens[i] == "1>>")
+      {
+        if (i + 1 >= tokens.size())
+        {
+          std::cerr << "Syntax error: expeceted filepath after '>>'\n";
+          continue;
+        }
+
+        appendStdout = true;
+        stdoutFile = tokens[i+1];
+
+        tokens.erase(tokens.begin() + i, tokens.begin() + i + 2);
+        continue;
+      }
+
+      if (tokens[i] == "2>>")
+      {
+        if (i + 1 >= tokens.size())
+        {
+          std::cerr << "Syntax error: expeceted filepath after '>>'\n";
+          continue;
+        }
+
+        appendStderr = true;
+        stderrFile = tokens[i+1];
+
+        tokens.erase(tokens.begin() + i, tokens.begin() + i + 2);
+        continue;
+      }
+
+      if (tokens[i] == ">" or tokens[i] == "1>")
+      {//stdout redirect
+        if (i + 1 >= tokens.size())
+        {//if no output specified, just remove and continue as normal
+          std::cerr << "Syntax error: expeceted filepath after '>'\n";
+          continue;
+        }
+
+        stdoutFile = tokens[i+1];
+        tokens.erase(tokens.begin() + i, tokens.begin() + i + 2);
+        continue;
+      }
+
+      if (tokens[i] == "2>")
+      {//stdout redirect
+        if (i + 1 >= tokens.size())
+        {//if no output specified, just remove and continue as normal
+          std::cerr << "Syntax error: expeceted filepath after '>'\n";
+          continue;
+        }
+
+        stderrFile = tokens[i+1];
+        tokens.erase(tokens.begin() + i, tokens.begin() + i + 2);
+        continue;
+      }
+      i++;
+    }
+
     std::optional<std::filesystem::path> result;
+    std::ostringstream output;
 
     switch (sh::Command command = sh::getCommand(tokens[0]))
     {
@@ -82,73 +149,43 @@ int main()
         shouldExit = true;
         break;
       case sh::Command::echo:
+        if (stderrFile)
+        {
+          std::ofstream err{stderrFile.value()};
+          err.close();
+        }
         for (int i = 1; i < tokens.size(); i++)
         {
-            std::cout << tokens[i] << " ";
+            output << tokens[i];
+            if (i < tokens.size() - 1) output << " ";
         }
-        std::cout << "\n";
+        stdoutFile ?
+          sh::printCommandStdout(output.str(), stdoutFile.value(), appendStdout) :
+          sh::printCommandStdout(output.str());
         break;
+
       case sh::Command::unknown:
         result = sh::isExec(tokens[0]);
         if (result)
         {
-          std::string filename = result.value().filename().string();
-          std::string fullPath = result.value().string();
-#ifdef _WIN32
-					std::vector<const char*> args;
-					args.push_back(filename.c_str());// have exe path on seperate element for _spawnv
-
-					for (size_t i = 1; i < tokens.size(); i++)
-					{
-						args.push_back(const_cast<char*>(tokens[i].c_str()));
-					}
-
-					args.push_back(nullptr);
-
-          intptr_t status = _spawnv(_P_WAIT, fullPath.c_str(), args.data());
-
-          if (status == -1)
-          {
-            perror("\n\nError executing program\n\n");
-            return 1;
-          }
-#else
-					std::vector<char*> args;
-					args.push_back(const_cast<char*>(filename.c_str()));// have exe path on seperate element for execv
-
-					for (size_t i = 1; i < tokens.size(); i++)
-					{
-						args.push_back(const_cast<char*>(tokens[i].c_str()));
-					}
-
-					args.push_back(nullptr);
-          pid_t pid = fork();
-          if (pid == 0)
-          {// child process
-            execv(result.value().c_str(), args.data());
-            perror("\n\nError executing program\n\n");
-            exit(1);
-          }
-          else
-          {
-            int status;
-            waitpid(pid, &status, 0);
-          }
-#endif
+          sh::executeCommand(result.value(), tokens, stdoutFile, stderrFile, appendStdout, appendStderr);
         }
         else
         {
-          std::cout << tokens[0] << ": command not found\n";
+          output << tokens[0] << ": command not found";
+          stdoutFile ?
+            sh::printCommandStdout(output.str(), stdoutFile.value()) :
+            sh::printCommandStdout(output.str());
         }
         break;
       case sh::Command::type:
-        sh::printType(tokens[1]);
+        sh::printType(tokens[1], stdoutFile);
         break;
       case sh::Command::pwd:
         std::cout << std::filesystem::current_path().string() << "\n";
         break;
       case sh::Command::cd:
-        sh::changeDir(tokens);
+        sh::changeDir(tokens, stdoutFile);
         break;
     }
   }

src/shellUtils.cpp

@@ -6,14 +6,23 @@
 #include <map>
 #include <cstdlib>
 #include <filesystem>
+#include <fstream>
+#include <sstream>
+#include <unistd.h>
+#include <fcntl.h> // For _O_RDWR, _O_CREAT, etc.
 
 #ifdef _WIN32
 #define HOME "USERPROFILE"
+#include <process.h>
+#include <io.h>
+#include <sys/stat.h> // For _S_IWRITE
 #else
+#include <unistd.h>
+#include <sys/wait.h>
+
 #define HOME "HOME"
 #endif
 
-
 namespace sh
 {
     void tokenize(std::vector<std::string>& tokens, const std::string& input)
@@ -67,19 +76,6 @@ namespace sh
         {
             tokens.emplace_back(currentToken);
         }
-
-//         std::istringstream tokens {input};
-//         std::string currentToken;
-//         while (tokens >> currentToken)
-//         {
-//             // check for escaped white space
-//             if (currentToken.back() == '\\')
-//             {//add whitespace to token
-//                 currentToken.append(1, ' ');
-//             }
-//             tokenContainer.emplace_back(currentToken);
-//         }
-
     }
 
     Command getCommand(std::string_view input)
@@ -140,31 +136,36 @@ namespace sh
 			return std::nullopt;
 		}
 
-    void printType(const std::string& input)
+    void printType(const std::string& input, const std::optional<std::filesystem::path>& stdoutFilePath)
     {
+        std::ostringstream output;
         if (commandMap.contains(input))
         {
-            std::cout << input;
-            std::cout << " is a shell builtin\n";
-            return;
+            output << input << " is a shell builtin";
         }
-
-        if (const auto fullPath {isExec(input)})
+        else if (const auto fullPath {isExec(input)})
         {
-            std::cout << input;
-            std::cout << " is " << fullPath.value().string() << "\n";
-            return;
+            output << input;
+            output << " is " << fullPath.value().string();
+        }
+        else
+        {
+            output << input;
+            output << ": not found";
         }
 
-        std::cout << input;
-        std::cout << ": not found\n";
-    }
+        stdoutFilePath ?
+            printCommandStdout(output.str(), stdoutFilePath.value()) :
+            printCommandStdout(output.str());
+      }
 
-    void changeDir(const std::vector<std::string>& tokens)
+    void changeDir(const std::vector<std::string>& tokens, const std::optional<std::filesystem::path>& stdoutFilePath)
     {
         if (tokens.size() > 2)
         {
-            std::cerr << "cd: too many arguments\n";
+            stdoutFilePath.has_value() ?
+                printCommandStderr("cd: too many arguments", stdoutFilePath.value()) :
+                printCommandStderr("cd: too many arguments");
             return;
         }
 
@@ -205,9 +206,207 @@ namespace sh
         }
         else
         {
-            std::cerr << "cd: " << expandedPath.string() << ": No such file or directory\n";
+            std::ostringstream output;
+            output << "cd: " << expandedPath.string() << ": No such file or directory";
+
+            stdoutFilePath.has_value() ?
+                printCommandStderr(output.str(), stdoutFilePath.value()) :
+                printCommandStderr(output.str());
         }
 
     }
 
+    void printCommandStdout(const std::string_view input, const std::optional<std::filesystem::path>& stdoutFilePath, bool append)
+    {
+        if (stdoutFilePath)
+        {
+            auto mode = append ? std::ios::app : std::ios::trunc;
+            std::ofstream output {stdoutFilePath.value(), mode};
+
+            if (!output)
+            {
+                std::cerr << "ERROR: cannot open " << stdoutFilePath.value().string() << "\n";
+            }
+            output << input << "\n";
+            output.close();
+            return;
+        }
+
+        std::cout << input << "\n";
+    }
+
+    void printCommandStderr(const std::string_view input, const std::optional<std::filesystem::path>& stderrFilePath, bool append)
+    {
+        if (stderrFilePath)
+        {
+            auto mode = append ? std::ios::app : std::ios::trunc;
+            std::ofstream output {stderrFilePath.value(), mode};
+
+            if (!output)
+            {
+                std::cerr << "ERROR: cannot open " << stderrFilePath.value().string() << "\n";
+            }
+            output << input;
+            output.close();
+            return;
+        }
+
+        std::cerr << input << "\n";
+    }
+
+    void executeCommand(const std::filesystem::path& exePath,const std::vector<std::string>& tokens, const std::optional<std::filesystem::path>& stdoutFilePath, const std::optional<std::filesystem::path>& stderrFilePath, bool appendStdout, bool appendStderr)
+    {
+        std::string filename = exePath.filename().string();
+        std::string fullPath = exePath.string();
+#ifdef _WIN32
+        std::vector<const char*> args;
+        args.push_back(filename.c_str());// have exe path on seperate element for _spawnv
+
+        for (size_t i = 1; i < tokens.size(); i++)
+        {
+            args.push_back(const_cast<char*>(tokens[i].c_str()));
+        }
+
+        args.push_back(nullptr);
+
+        int originalStdout = -1;
+        int originalStderr = -1;
+        int stdoutFd = -1;
+        int stderrFd = -1;
+
+        if (stdoutFilePath)
+        {
+            originalStdout = _dup(1); // save out connection to the shell
+
+            if (appendStdout)
+            {
+                stdoutFd = _open(stdoutFilePath.value().c_str(), _O_WRONLY | _O_CREAT, _S_IWRITE);
+            }
+            else
+            {
+                stdoutFd = _open(stdoutFilePath.value().c_str(), _O_WRONLY | _O_CREAT | _O_TRUNC, _S_IWRITE);
+            }
+
+            if (stdoutFd == -1)
+            {
+                perror("Could not open redirect file\n");
+                _close(originalStdout);
+                return;
+            }
+            _dup2(stdoutFd, 1);
+        }
+
+        if (stderrFilePath)
+        {
+            originalStderr = _dup(2);
+            if (appendStderr)
+            {
+                stderrFd = _open(stderrFilePath.value().c_str(), _O_WRONLY | _O_CREAT | _O_APPEND, _S_IWRITE);
+            }
+            else
+            {
+                stderrFd = _open(stderrFilePath.value().c_str(), _O_WRONLY | _O_CREAT | _O_TRUNC, _S_IWRITE);
+            }
+
+            if (stderrFd == -1)
+            {
+                perror("could not redirect stderr to file");
+                return;
+            }
+            _dup2(stderrFd, 2);
+        }
+
+        intptr_t status = _spawnv(_P_WAIT, fullPath.c_str(), args.data());
+
+        if (stdoutFilePath)
+        {
+            _dup2(originalStdout, 1);
+            _close(originalStdout);
+            _close(stdoutFd);
+        }
+
+        if (stderrFilePath)
+        {
+            _dup2(originalStderr, 2);
+            _close(originalStderr);
+            _close(stderrFd);
+        }
+
+        if (status == -1)
+        {
+            perror("\n\nError executing program\n\n");
+            return;
+        }
+#else
+        std::vector<char*> args;
+        args.push_back(const_cast<char*>(filename.c_str()));// have exe path on seperate element for execv
+
+        for (size_t i = 1; i < tokens.size(); i++)
+        {
+            args.push_back(const_cast<char*>(tokens[i].c_str()));
+        }
+
+        args.push_back(nullptr);
+        pid_t pid = fork();
+        if (pid == 0)
+        {// child process
+            if (stdoutFilePath)
+            {
+                int fileFd;
+                if (appendStdout)
+                {
+                    fileFd = open(stdoutFilePath.value().c_str(), O_WRONLY | O_CREAT | O_APPEND, 0644);// 0644: Permissions (rw-r--r--)
+                }
+                else
+                {
+                    fileFd = open(stdoutFilePath.value().c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0644);// 0644: Permissions (rw-r--r--)
+                }
+
+                if (fileFd == -1)
+                {
+                    perror("Error opening redirect file\n");
+                    exit(1);
+                }
+
+                dup2(fileFd, STDOUT_FILENO);
+
+                close(fileFd);
+            }
+
+            if (stderrFilePath)
+            {
+                int fileFd;
+                if (appendStderr)
+                {
+                    fileFd = open(stderrFilePath.value().c_str(), O_WRONLY | O_CREAT| O_APPEND, 0644);// 0644: Permissions (rw-r--r--)
+                }
+                else
+                {
+                    fileFd = open(stderrFilePath.value().c_str(), O_WRONLY | O_CREAT | O_TRUNC, 0644);// 0644: Permissions (rw-r--r--)
+                }
+
+                if (fileFd == -1)
+                {
+                    perror("Error opening redirect file\n");
+                    exit(1);
+                }
+
+                dup2(fileFd, STDERR_FILENO);
+
+                close(fileFd);
+            }
+
+            execv(exePath.c_str(), args.data());
+            perror("\n\nError executing program\n\n");
+            exit(1);
+        }
+        else
+        {
+            int status;
+            waitpid(pid, &status, 0);
+        }
+#endif
+
+    }
+
 }