diff options
Diffstat (limited to 'include/mts/MTS_System.h')
| -rw-r--r-- | include/mts/MTS_System.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/include/mts/MTS_System.h b/include/mts/MTS_System.h index bd5fa53..d51a5ea 100644 --- a/include/mts/MTS_System.h +++ b/include/mts/MTS_System.h @@ -31,6 +31,7 @@ #include <mts/MTS_NonConstructable.h> #include <mts/MTS_Stdint.h> #include <string> +#include <vector> namespace MTS { @@ -38,6 +39,17 @@ namespace MTS { public: + //! Type of the pipe to be opened in executeBackground + enum class PipeType { + READ, WRITE + }; + + //! Utility structure with information about the child process + struct ChildHandle { + pid_t pid; + FILE* stream; + }; + //UTC (Coordinated Universal Time) : This is the standard international time or the Greenwich Mean Time. //EPOCH : number of seconds elapsed since 00:00:00 on January 1, 1970, Coordinated Universal Time. @@ -53,6 +65,78 @@ namespace MTS { static int32_t cmd(const std::string& cmd, std::string& result); static int32_t readFile(const std::string& path, std::string& result); + + //! Execute application with specified arguments. + /*! + * A safer alternative to System::cmd that allows to execute applications with controlled + * list of arguments bypasing the system shell. + * + * \param cmd name of the application to be executed + * \param argv vector of arguments (excluding argument zero) + * \param result stdout output from the application is stored here + * \return result code as for std::system and UNIX pclose + */ + static int32_t execute(const std::string& cmd, const std::vector<std::string>& argv, std::string& result); + + //! Spawn a process and open pipe with the specified type (READ or WRITE) + /*! + * A safer alternative to POSIX popen that allows to execute applications with controlled + * list of arguments bypasing the system shell. If succeded, information about the spawned + * process is written to the \p child structure. + * + * \param cmd name of the application to be executed + * \param argv vector of arguments (excluding argument zero) + * \param type open pipe for read from child or write to child + * \param child on success is populated with child process information, on failure is not defined + * \return true on success, false on failure + */ + static bool executeBackground(const std::string& cmd, const std::vector<std::string>& argv, PipeType type, ChildHandle& child); + + //! Close the pipe and wait for a child to finish execution + /*! + * \param child structure with child process information as populated by executeBackground + * \return result code as for std::system and UNIX pclose + */ + static int closeBackground(ChildHandle& child); + + private: + + //! Spawn a process and open pipe with the specified type (READ or WRITE) + static bool executeBackground(const std::string& cmd, char* const argv[], PipeType type, ChildHandle& child); + + //! Utility method. Cast argument to a C pointer required by some C-style functions. + static inline char* castArgument(const std::string& arg); + + //! Utility method. Convert argument vector to a format required by execve and posix_spawn. + static std::vector<char*> castArgVector(const std::string& cmd, const std::vector<std::string>& argv); + + //! Lightweight C++ wrapper with auto-close for file descriptors + class FdWrapper { + + public: + static const int FD_NOT_READY = -1; + + explicit FdWrapper(int fd = FD_NOT_READY); + ~FdWrapper(); + + inline int get() const; + int release(); + void reset(int fd = FD_NOT_READY); + + private: + int m_fd; + + }; + + //! Utility structure, used by popen wrapper + struct Pipe { + FdWrapper parent; + FdWrapper child; + }; + + //! Initialize UNIX pipe + static int initPipe(Pipe& pipe, PipeType type); + }; } |