2 Copyright (C) 2010 Paul Davis
3 Copyright (C) 2010-2014 Robin Gareus <robin@gareus.org>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #ifndef _libpbd_system_exec_h_
21 #define _libpbd_system_exec_h_
24 #define STDIN_FILENO 0
27 #define STDOUT_FILENO 1
30 #define STDERR_FILENO 2
33 #ifdef PLATFORM_WINDOWS
37 #undef interface // VKamyshniy: to avoid "include/giomm-2.4/giomm/dbusmessage.h:270:94: error: expected ',' or '...' before 'struct'"
41 #include <sys/types.h>
42 #include <sys/wait.h> /* WNOHANG is part of the exposed API */
50 #ifdef NOPBD /* unit-test outside ardour */
51 #include <sigc++/bind.h>
52 #include <sigc++/signal.h>
54 #include "pbd/signals.h"
59 /** @class: SystemExec
60 * @brief execute an external command
62 * This class allows launche an external command-line application
63 * opening a full-duplex connection to its standard I/O.
65 * In Ardour context it is used to launch xjadeo and ffmpeg.
67 * The \ref write_to_stdin function provides for injecting data into STDIN
68 * of the child-application while output of the program to STDOUT/STDERR is
69 * forwarded using the \ref ReadStdout signal.
70 * \ref Terminated is sent if the child application exits.
73 class LIBPBD_API SystemExec
76 /** prepare execution of a program with 'execve'
78 * This function takes over the existing environment variable and provides
79 * an easy way to speciy command-line arguments for the new process.
81 * Note: The argument parser does not interpret quotation-marks and splits
82 * arugments on whitespace. The argument string can be empty.
83 * The alternative constructor below allows to specify quoted parameters
86 * @param c program pathname that identifies the new process image file.
87 * @param a string of commandline-arguments to be passed to the new program.
89 SystemExec (std::string c, std::string a = "");
90 /** similar to \ref SystemExec but allows to specify custom arguments
92 * @param c program pathname that identifies the new process image file.
93 * @param a array of argument strings passed to the new program as 'argv'.
94 * it must be terminated by a null pointer (see the 'evecve'
95 * POSIX-C documentation for more information)
96 * The array must be dynamically allocated using malloc or strdup.
97 * Unless they're NULL, the array itself and each of its content
98 * memory is freed() in the destructor.
101 SystemExec (std::string c, char ** a);
103 /** similar to \ref SystemExec but expects a whole command line, and
104 * handles some simple escape sequences.
106 * @param command complete command-line to be executed
107 * @param subs a map of <char, std::string> listing the % substitutions to
110 * creates an argv array from the given command string, splitting into
111 * parameters at spaces.
112 * "\ " is non-splitting space, "\\" (and "\" at end of command) as "\",
113 * for "%<char>", <char> is looked up in subs and the corresponding string
114 * substituted. "%%" (and "%" at end of command)
115 * returns an argv array suitable for creating a new SystemExec with
117 SystemExec (std::string command, const std::map<char, std::string> subs);
119 virtual ~SystemExec ();
121 static char* format_key_value_parameter (std::string, std::string);
123 std::string to_s() const;
125 /** fork and execute the given program
127 * @param stderr_mode select what to do with program's standard error
129 * '0': keep STDERR; mix it with parent-process' STDERR
130 * '1': ignore STDERR of child-program
131 * '2': merge STDERR into STDOUT and send it with the
133 * @return If the process is already running or was launched successfully
134 * the function returns zero (0). A negative number indicates an error.
136 int start (int stderr_mode, const char *_vfork_exec_wrapper);
137 /** kill running child-process
139 * if a child process exists trt to shut it down by closing its STDIN.
140 * if the program dies not react try SIGTERM and eventually SIGKILL
143 /** check if the child programm is (still) running.
145 * This function calls waitpid(WNOHANG) to check the state of the
147 * @return true if the program is (still) running.
150 /** call the waitpid system-call with the pid of the child-program
152 * Basically what \ref terminate uses internally.
154 * This function is only useful if you want to control application
155 * termination yourself (eg timeouts or progress-dialog).
156 * @param option flags - see waitpid manual
157 * @return status info from waitpid call (not waitpid's return value)
158 * or -1 if the child-program is not running.
160 int wait (int options=0);
161 /** closes both STDIN and STDOUT connections to/from
163 * With the output-interposer thread gone, the program
165 * used by \ref terminate()
168 /** write into child-program's STDIN
169 * @param d text to write
170 * @param len length of data to write, if it is 0 (zero), d.length() is
171 * used to determine the number of bytes to transmit.
172 * @return number of bytes written.
174 size_t write_to_stdin (std::string const& d, size_t len=0);
176 /** write into child-program's STDIN
177 * @param data data to write
178 * @param bytes length of data to write
179 * @return number of bytes written.
181 size_t write_to_stdin (const void* d, size_t bytes=0);
183 /** The ReadStdout signal is emitted when the application writes to STDOUT.
184 * it passes the written data and its length in bytes as arguments to the bound
187 #ifdef NOPBD /* outside ardour */
188 sigc::signal<void, std::string,size_t> ReadStdout;
190 PBD::Signal2<void, std::string,size_t> ReadStdout;
193 /** The Terminated signal is emitted when application terminates. */
194 #ifdef NOPBD /* outside ardour */
195 sigc::signal<void> Terminated;
197 PBD::Signal0<void> Terminated;
200 /** interposer to emit signal for writes to STDOUT/ERR.
202 * Thread that reads the stdout of the forked
203 * process and signal-sends it to the main thread.
204 * It also emits the Terminated() signal once
205 * the the forked process closes it's stdout.
207 * Note: it's actually 'private' function but used
208 * by the internal pthread, which only has a pointer
209 * to this instance and thus can only access public fn.
211 void output_interposer ();
214 std::string cmd; ///< path to command - set when creating the class
215 int nicelevel; ///< process nice level - defaults to 0
217 void make_argp(std::string);
218 void make_argp_escaped(std::string command, const std::map<char, std::string> subs);
225 #ifdef PLATFORM_WINDOWS
226 PROCESS_INFORMATION *pid;
231 void make_wargs(char **);
239 pthread_mutex_t write_lock;
245 pthread_t thread_id_tt;
250 }; /* end namespace */
252 #endif /* _libpbd_system_exec_h_ */