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 #if defined (__MINGW64__)
37 #undef interface // VKamyshniy: to avoid "include/giomm-2.4/giomm/dbusmessage.h:270:94: error: expected ',' or '...' before 'struct'"
45 #ifdef NOPBD /* unit-test outside ardour */
46 #include <sigc++/bind.h>
47 #include <sigc++/signal.h>
49 #include "pbd/signals.h"
54 /** @class: SystemExec
55 * @brief execute an external command
57 * This class allows launche an external command-line application
58 * opening a full-duplex connection to its standard I/O.
60 * In Ardour context it is used to launch xjadeo and ffmpeg.
62 * The \ref write_to_stdin function provides for injecting data into STDIN
63 * of the child-application while output of the program to STDOUT/STDERR is
64 * forwarded using the \ref ReadStdout signal.
65 * \ref Terminated is sent if the child application exits.
68 class LIBPBD_API SystemExec
71 /** prepare execution of a program with 'execve'
73 * This function takes over the existing environment variable and provides
74 * an easy way to speciy command-line arguments for the new process.
76 * Note: The argument parser does not interpret quotation-marks and splits
77 * arugments on whitespace. The argument string can be empty.
78 * The alternative constructor below allows to specify quoted parameters
81 * @param c program pathname that identifies the new process image file.
82 * @param a string of commandline-arguments to be passed to the new program.
84 SystemExec (std::string c, std::string a = "");
85 /** similar to \ref SystemExec but allows to specify custom arguments
87 * @param c program pathname that identifies the new process image file.
88 * @param a array of argument strings passed to the new program as 'argv'.
89 * it must be terminated by a null pointer (see the 'evecve'
90 * POSIX-C documentation for more information)
91 * The array must be dynamically allocated using malloc or strdup.
92 * Unless they're NULL, the array itself and each of its content
93 * memory is freed() in the destructor.
96 SystemExec (std::string c, char ** a);
97 virtual ~SystemExec ();
99 /** fork and execute the given program
101 * @param stderr_mode select what to do with program's standard error
103 * '0': keep STDERR; mix it with parent-process' STDERR
104 * '1': ignore STDERR of child-program
105 * '2': merge STDERR into STDOUT and send it with the
107 * @return If the process is already running or was launched successfully
108 * the function returns zero (0). A negative number indicates an error.
110 int start (int stderr_mode = 1);
111 /** kill running child-process
113 * if a child process exists trt to shut it down by closing its STDIN.
114 * if the program dies not react try SIGTERM and eventually SIGKILL
117 /** check if the child programm is (still) running.
119 * This function calls waitpid(WNOHANG) to check the state of the
121 * @return true if the program is (still) running.
124 /** call the waitpid system-call with the pid of the child-program
126 * Basically what \ref terminate uses internally.
128 * This function is only useful if you want to control application
129 * termination yourself (eg timeouts or progress-dialog).
130 * @param option flags - see waitpid manual
131 * @return status info from waitpid call (not waitpid's return value)
132 * or -1 if the child-program is not running.
134 int wait (int options=0);
135 /** closes both STDIN and STDOUT connections to/from
137 * With the output-interposer thread gone, the program
139 * used by \ref terminate()
142 /** write into child-program's STDIN
143 * @param d data to write
144 * @param len length of data to write, if it is 0 (zero), d.length() is
145 * used to determine the number of bytes to transmit.
146 * @return number of bytes written.
148 int write_to_stdin (std::string d, size_t len=0);
150 /** The ReadStdout signal is emitted when the application writes to STDOUT.
151 * it passes the written data and its length in bytes as arguments to the bound
154 #ifdef NOPBD /* outside ardour */
155 sigc::signal<void, std::string,size_t> ReadStdout;
157 PBD::Signal2<void, std::string,size_t> ReadStdout;
160 /** The Terminated signal is emitted when application terminates. */
161 #ifdef NOPBD /* outside ardour */
162 sigc::signal<void> Terminated;
164 PBD::Signal0<void> Terminated;
167 /** interposer to emit signal for writes to STDOUT/ERR.
169 * Thread that reads the stdout of the forked
170 * process and signal-sends it to the main thread.
171 * It also emits the Terminated() signal once
172 * the the forked process closes it's stdout.
174 * Note: it's actually 'private' function but used
175 * by the internal pthread, which only has a pointer
176 * to this instance and thus can only access public fn.
178 void output_interposer ();
181 std::string cmd; ///< path to command - set when creating the class
182 int nicelevel; ///< process nice level - defaults to 0
184 void make_argp(std::string);
191 #ifdef PLATFORM_WINDOWS
192 PROCESS_INFORMATION *pid;
197 void make_wargs(char **);
201 pthread_mutex_t write_lock;
203 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.
208 pthread_t thread_id_tt;
213 }; /* end namespace */
215 #endif /* _libpbd_system_exec_h_ */