Improve direct execution

+ Add -o option
+ Add shebang analysis
+ Implement missing cleanup

README.md

@@ -16,9 +16,23 @@ These commands can be placed anywhere within the script like regular commands.
 
 ## Other features
 
+### Output generated code
+
+Output the generated shell code to stdout with either:
+- `-o` option
+- shebang other than lxsh
+
+> Redirect stdout to a file to create a script file. <br>
+> The resulting script is not dependent on lxsh
+
 ### Live execution
 
-Execute an extended shell script directly with the `-e` option.
+Directly execute an extended shell script with either
+- `-e` option
+- shebang is lxsh
+
+> Direct execution introduces direct dependency on lxsh and overhead,
+> therefore it should be avoided outside of development use
 
 ### Minimize code
 
@@ -30,5 +44,6 @@ lxsh should currently fully support POSIX syntax. <br>
 A POSIX shell script should give a working output.
 
 Some specific features are missing:
-- link commands inside arithmetics (`$(())`) are not resolved
+- link commands in subshells inside arithmetics are not resolved
+- arithmetics cannot be minimized
 - link commands placed on the same line as keywords `if`, `then`, `elif`, `else`, `for`, `while`, `do` or `done` are not resolved

include/util.hpp

@@ -34,7 +34,7 @@ std::string delete_brackets(std::string const& in);
 
 std::string pwd();
 
-void _exec(std::string const& bin, std::vector<std::string> const& args);
+int _exec(std::string const& bin, std::vector<std::string> const& args);
 
 std::string stringReplace(std::string subject, const std::string& search, const std::string& replace);
 

src/main.cpp

@@ -12,6 +12,48 @@
 #include "parse.hpp"
 #include "options.hpp"
 
+int execute(block& sh, std::vector<std::string>& args)
+{
+  std::string data=sh.generate();
+
+  std::string filename=ztd::exec("basename", args[0]).first;
+  filename.pop_back();
+
+  // generate path
+  std::string tmpdir = (getenv("TMPDIR") != NULL) ? getenv("TMPDIR") : "/tmp" ;
+  std::string dirpath = tmpdir + "/lxsh_" + ztd::sh("tr -dc '[:alnum:]' < /dev/urandom | head -c10");
+  std::string filepath = dirpath+'/'+filename;
+
+  // create dir
+  if(ztd::exec("mkdir", "-p", dirpath).second)
+  {
+    throw std::runtime_error("Failed to create directory '"+dirpath+'\'');
+  }
+
+  // create stream
+  std::ofstream stream(filepath);
+  if(!stream)
+  {
+    ztd::exec("rm", "-rf", dirpath);
+    throw std::runtime_error("Failed to write to '"+filepath+'\'');
+  }
+
+  // output
+  stream << data;
+  stream.close();
+  if(ztd::exec("chmod", "+x", filepath).second != 0)
+  {
+    ztd::exec("rm", "-rf", dirpath);
+    throw std::runtime_error("Failed to make '"+filepath+"' executable");
+  }
+
+  // exec
+  int retval=_exec(filepath, args);
+  ztd::exec("rm", "-rf", dirpath);
+
+  return retval;
+}
+
 int main(int argc, char* argv[])
 {
   auto args=options.process(argc, argv, false, true);
@@ -59,37 +101,36 @@ int main(int argc, char* argv[])
     }
   }
 
+
   g_origin=file;
   add_include(file);
 
   try
   {
     block sh(parse(import_file(file)));
+    std::string curbin, binshebang;
+    curbin=ztd::exec("basename", argv[0]).first;
+    binshebang=ztd::exec("basename", sh.shebang).first;
+    if(binshebang==curbin)
+      sh.shebang="#!/bin/sh";
     if(options['e'])
     {
-      std::string data=sh.generate();
-      // generate path
-      std::string tmpdir = (getenv("TMPDIR") != NULL) ? getenv("TMPDIR") : "/tmp" ;
-      std::string filepath = tmpdir + "/lxsh_exec_" + ztd::sh("tr -dc '[:alnum:]' < /dev/urandom | head -c10");
-      // create stream
-      std::ofstream stream(filepath);
-      if(!stream)
-        throw std::runtime_error("Failed to write to file '"+filepath+'\'');
-
-      // output
-      stream << data;
-      stream.close();
-      auto p = ztd::exec("chmod", "+x", filepath);
-      if(p.second != 0)
-        return p.second;
-
-      args.erase(args.begin());
-      _exec(filepath, args);
-
+      return execute(sh, args);
+    }
+    else if(options['o'])
+    {
+      std::cout << sh.generate();
     }
     else
     {
-      std::cout << sh.generate();
+      if(binshebang == curbin)
+      {
+        return execute(sh, args);
+      }
+      else
+      {
+        std::cout << sh.generate();
+      }
     }
   }
   catch(ztd::format_error& e)

src/options.cpp

@@ -9,7 +9,8 @@ ztd::option_set gen_options()
   ztd::option_set ret;
   ret.add(ztd::option('h', "help",     false, "Display this help message"));
   ret.add(ztd::option('m', "minimize", false, "Minimize code"));
-  ret.add(ztd::option('e', "exec",     false, "Directly exec instead of outputting"));
+  ret.add(ztd::option('e', "exec",     false, "Directly execute script"));
+  ret.add(ztd::option('o', "output",   false, "Output result script to stdout"));
   ret.add(ztd::option("help-commands", false, "Print help for linker commands"));
   return ret;
 }

src/util.cpp

@@ -1,6 +1,10 @@
 #include "util.hpp"
 
 #include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include <iostream>
 
 #include <ztd/shell.hpp>
 
@@ -69,14 +73,40 @@ std::string pwd()
   return std::string(buf);
 }
 
-void _exec(std::string const& bin, std::vector<std::string> const& args)
+int _exec(std::string const& bin, std::vector<std::string> const& args)
 {
   std::vector<char*> rargs;
-  rargs.push_back((char*) bin.c_str());
   for(auto it=args.begin(); it!=args.end(); it++)
     rargs.push_back((char*) it->c_str());
   rargs.push_back(NULL);
-  execvp(bin.c_str(), rargs.data());
+
+  pid_t pid;
+
+  // forking
+  if((pid = fork()) == -1)
+  {
+    perror("fork");
+    exit(1);
+  }
+  // child process
+  if(pid == 0)
+  {
+    setpgid(pid, pid); //Needed so negative PIDs can kill children of /bin/sh
+    execvp(bin.c_str(), rargs.data());
+    exit(1); // exec didn't work
+  }
+
+  int stat;
+  // wait for end and get return value
+  while (waitpid(pid, &stat, 0) == -1)
+  {
+    if (errno != EINTR)
+    {
+      stat = -1;
+      break;
+    }
+  }
+  return stat;
 }
 
 std::string stringReplace(std::string subject, const std::string& search, const std::string& replace)
@@ -134,4 +164,3 @@ void printErrorIndex(const char* in, const int index, const std::string& message
     }
   }
 }
-