2 Copyright (C) 2010 Paul Davis
3 Author: 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 #ifdef WITH_VIDEOTIMELINE
22 #ifndef __ardour_system_exec_h__
23 #define __ardour_system_exec_h__
26 #define STDIN_FILENO 0
29 #define STDOUT_FILENO 1
32 #define STDERR_FILENO 2
38 #ifdef NOPBD /* outside ardour */
39 #include <sigc++/bind.h>
40 #include <sigc++/signal.h>
42 #include <pbd/signals.h>
45 /** @class: SystemExec
46 * @brief execute an external command
48 * This class allows launche an external command-line application
49 * opening a full-duplex connection to its standard I/O.
51 * In Ardour context it is used to launch xjadeo and ffmpeg.
53 * The \ref write_to_stdin function provides for injecting data into STDIN
54 * of the child-application while output of the program to STDOUT/STDERR is
55 * forwarded using the \ref ReadStdout signal.
56 * \ref Terminated is sent if the child application exits.
62 /** prepare execution of a program with 'execve'
64 * This function takes over the existing environment variable and provides
65 * an easy way to speciy command-line arguments for the new process.
67 * Note: The argument parser does not interpret quotation-marks and splits
68 * arugments on whitespace. The argument string can be empty.
69 * The alternative constructor below allows to specify quoted parameters
72 * @param c program pathname that identifies the new process image file.
73 * @param a string of commandline-arguments to be passed to the new program.
75 SystemExec (std::string c, std::string a = "");
76 /** similar to \ref SystemExec but allows to specify custom arguments
78 * @param c program pathname that identifies the new process image file.
79 * @param a array of argument strings passed to the new program as 'argv'.
80 * it must be terminated by a null pointer (see the 'evecve'
81 * POSIX-C documentation for more information)
82 * The array must be dynamically allocated using malloc or strdup.
83 * Unless they're NULL, the array itself and each of its content
84 * memory is freed() in the destructor.
87 SystemExec (std::string c, char ** a);
88 virtual ~SystemExec ();
90 /** fork and execute the given program
92 * @param stderr_mode select what to do with program's standard error
94 * '0': keep STDERR; mix it with parent-process' STDERR
95 * '1': ignore STDERR of child-program
96 * '2': merge STDERR into STDOUT and send it with the
98 * @return If the process is already running or was launched successfully
99 * the function returns zero (0). A negative number indicates an error.
101 int start (int stderr_mode = 1);
102 /** kill running child-process
104 * if a child process exists trt to shut it down by closing its STDIN.
105 * if the program dies not react try SIGTERM and eventually SIGKILL
108 /** check if the child programm is (still) running.
110 * This function calls waitpid(WNOHANG) to check the state of the
112 * @return true if the program is (still) running.
115 /** call the waitpid system-call with the pid of the child-program
117 * Basically what \ref terminate uses internally.
119 * This function is only useful if you want to control application
120 * termination yourself (eg timeouts or progress-dialog).
121 * @param option flags - see waitpid manual
122 * @return status info from waitpid call (not waitpid's return value)
123 * or -1 if the child-program is not running.
125 int wait (int options=0);
126 /** closes both STDIN and STDOUT connections to/from
128 * With the output-interposer thread gone, the program
130 * used by \ref terminate()
133 /** write into child-program's STDIN
134 * @param d data to write
135 * @param len length of data to write, if it is 0 (zero), d.length() is
136 * used to determine the number of bytes to transmit.
137 * @return number of bytes written.
139 int write_to_stdin (std::string d, size_t len=0);
141 /** The ReadStdout signal is emitted when the application writes to STDOUT.
142 * it passes the written data and its length in bytes as arguments to the bound
145 #ifdef NOPBD /* outside ardour */
146 sigc::signal<void, std::string,size_t> ReadStdout;
148 PBD::Signal2<void, std::string,size_t> ReadStdout;
151 /** The Terminated signal is emitted when application terminates. */
152 #ifdef NOPBD /* outside ardour */
153 sigc::signal<void> Terminated;
155 PBD::Signal0<void> Terminated;
158 /** interposer to emit signal for writes to STDOUT/ERR.
160 * Thread that reads the stdout of the forked
161 * process and signal-sends it to the main thread.
162 * It also emits the Terminated() signal once
163 * the the forked process closes it's stdout.
165 * Note: it's actually 'private' function but used
166 * by the internal pthread, which only has a pointer
167 * to this instance and thus can only access public fn.
169 void output_interposer ();
172 std::string cmd; ///< path to command - set when creating the class
173 int nicelevel; ///< process nice level - defaults to 0
175 void make_argp(std::string);
183 PROCESS_INFORMATION *pid;
188 void make_wargs(char **);
192 pthread_mutex_t write_lock;
194 int fdin; ///< file-descriptor for writing to child's STDIN. This variable is identical to pin[1] but also used as status check if the stdin pipe is open: <0 means closed.
199 pthread_t thread_id_tt;
203 #endif /* __ardour_system_exec_h__ */
204 #endif /* WITH_VIDEOTIMELINE */