fix(command): Use execlp()

Ref #214

include/utils/command.hpp

@@ -50,7 +50,7 @@ namespace command_util {
     bool is_running();
     int wait();
 
-    void tail(callback<string> callback);
+    void tail(callback<string> cb);
     int writeline(string data);
     string readline();
 

include/utils/process.hpp

@@ -9,7 +9,7 @@ namespace process_util {
   bool in_forked_process(pid_t pid);
 
   void exec(char* cmd, char** args);
-  void exec(const string& cmd);
+  void exec_sh(const char* cmd);
 
   pid_t wait_for_completion(pid_t process_id, int* status_addr, int waitflags = 0);
   pid_t wait_for_completion(int* status_addr, int waitflags = 0);

src/modules/script.cpp

@@ -84,14 +84,8 @@ namespace modules {
     }
 
     try {
-      if (m_command && m_command->is_running()) {
-        m_log.warn("%s: Previous shell command is still running...", name());
-        return false;
-      }
-
       auto exec = string_util::replace_all(m_exec, "%counter%", to_string(++m_counter));
-      m_log.trace("%s: Executing '%s'", name(), exec);
-
+      m_log.info("%s: Executing \"%s\"", name(), exec);
       m_command = command_util::make_command(exec);
       m_command->exec();
       m_command->tail([&](string output) { m_output = output; });

src/utils/command.cpp

@@ -11,7 +11,7 @@
 POLYBAR_NS
 
 namespace command_util {
-  command::command(const logger& logger, string cmd) : m_log(logger), m_cmd("/usr/bin/env\nsh\n-c\n" + cmd) {
+  command::command(const logger& logger, string cmd) : m_log(logger), m_cmd(cmd) {
     if (pipe(m_stdin) != 0) {
       throw command_strerror("Failed to allocate input stream");
     }
@@ -76,9 +76,7 @@ namespace command_util {
       process_util::unblock_signal(SIGTERM);
 
       setpgid(m_forkpid, 0);
-      process_util::exec(m_cmd);
-
-      throw command_error("Exec failed");
+      process_util::exec_sh(m_cmd.c_str());
     } else {
       // Close file descriptors that won't be used by the parent
       if ((m_stdin[PIPE_READ] = close(m_stdin[PIPE_READ])) == -1) {
@@ -155,8 +153,8 @@ namespace command_util {
    * @note: This is a blocking call and will not
    * end until the stream is closed
    */
-  void command::tail(callback<string> callback) {
-    io_util::tail(m_stdout[PIPE_READ], move(callback));
+  void command::tail(callback<string> cb) {
+    io_util::tail(m_stdout[PIPE_READ], move(cb));
   }
 
   /**

src/utils/io.cpp

@@ -93,7 +93,7 @@ namespace io_util {
   }
 
   void tail(int read_fd, int writeback_fd) {
-    tail(read_fd, [&writeback_fd](string data) { io_util::writeline(writeback_fd, data); });
+    tail(read_fd, [&](string data) { io_util::writeline(writeback_fd, data); });
   }
 
   bool poll(int fd, short int events, int timeout_ms) {

src/utils/process.cpp

@@ -2,6 +2,7 @@
 #include <unistd.h>
 
 #include "errors.hpp"
+#include "utils/env.hpp"
 #include "utils/process.hpp"
 #include "utils/string.hpp"
 
@@ -23,7 +24,7 @@ namespace process_util {
   }
 
   /**
-   * Replace current process
+   * Execute command
    */
   void exec(char* cmd, char** args) {
     execvp(cmd, args);
@@ -31,23 +32,12 @@ namespace process_util {
   }
 
   /**
-   * Replace process with command
+   * Execute command using shell
    */
-  void exec(const string& cmd) {
-    vector<char*> c_args;
-    vector<string> args;
-
-    if (string_util::contains(cmd, "\n")) {
-      string_util::split_into(cmd, '\n', args);
-    } else {
-      string_util::split_into(cmd, ' ', args);
-    }
-
-    for (auto&& argument : args) {
-      c_args.emplace_back(const_cast<char*>(argument.c_str()));
-    }
-
-    exec(c_args[0], c_args.data());
+  void exec_sh(const char* cmd) {
+    static const char* shell = env_util::get("SHELL", "/bin/sh").c_str();
+    execlp(shell, shell, "-c", cmd, nullptr);
+    throw system_error("execvp() failed");
   }
 
   /**