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'"
47 #ifdef NOPBD /* unit-test outside ardour */
48 #include <sigc++/bind.h>
49 #include <sigc++/signal.h>
51 #include "pbd/signals.h"
56 /** @class: SystemExec
57 * @brief execute an external command
59 * This class allows launche an external command-line application
60 * opening a full-duplex connection to its standard I/O.
62 * In Ardour context it is used to launch xjadeo and ffmpeg.
64 * The \ref write_to_stdin function provides for injecting data into STDIN
65 * of the child-application while output of the program to STDOUT/STDERR is
66 * forwarded using the \ref ReadStdout signal.
67 * \ref Terminated is sent if the child application exits.
70 class LIBPBD_API SystemExec
73 /** prepare execution of a program with 'execve'
75 * This function takes over the existing environment variable and provides
76 * an easy way to speciy command-line arguments for the new process.
78 * Note: The argument parser does not interpret quotation-marks and splits
79 * arugments on whitespace. The argument string can be empty.
80 * The alternative constructor below allows to specify quoted parameters
83 * @param c program pathname that identifies the new process image file.
84 * @param a string of commandline-arguments to be passed to the new program.
86 SystemExec (std::string c, std::string a = "");
87 /** similar to \ref SystemExec but allows to specify custom arguments
89 * @param c program pathname that identifies the new process image file.
90 * @param a array of argument strings passed to the new program as 'argv'.
91 * it must be terminated by a null pointer (see the 'evecve'
92 * POSIX-C documentation for more information)
93 * The array must be dynamically allocated using malloc or strdup.
94 * Unless they're NULL, the array itself and each of its content
95 * memory is freed() in the destructor.
98 SystemExec (std::string c, char ** a);
100 /** similar to \ref SystemExec but expects a whole command line, and
101 * handles some simple escape sequences.
103 * @param command complete command-line to be executed
104 * @param subs a map of <char, std::string> listing the % substitutions to
107 * creates an argv array from the given command string, splitting into
108 * parameters at spaces.
109 * "\ " is non-splitting space, "\\" (and "\" at end of command) as "\",
110 * for "%<char>", <char> is looked up in subs and the corresponding string
111 * substituted. "%%" (and "%" at end of command)
112 * returns an argv array suitable for creating a new SystemExec with
114 SystemExec (std::string command, const std::map<char, std::string> subs);
116 virtual ~SystemExec ();
118 /** fork and execute the given program
120 * @param stderr_mode select what to do with program's standard error
122 * '0': keep STDERR; mix it with parent-process' STDERR
123 * '1': ignore STDERR of child-program
124 * '2': merge STDERR into STDOUT and send it with the
126 * @return If the process is already running or was launched successfully
127 * the function returns zero (0). A negative number indicates an error.
129 int start (int stderr_mode, const char *_vfork_exec_wrapper);
130 /** kill running child-process
132 * if a child process exists trt to shut it down by closing its STDIN.
133 * if the program dies not react try SIGTERM and eventually SIGKILL
136 /** check if the child programm is (still) running.
138 * This function calls waitpid(WNOHANG) to check the state of the
140 * @return true if the program is (still) running.
143 /** call the waitpid system-call with the pid of the child-program
145 * Basically what \ref terminate uses internally.
147 * This function is only useful if you want to control application
148 * termination yourself (eg timeouts or progress-dialog).
149 * @param option flags - see waitpid manual
150 * @return status info from waitpid call (not waitpid's return value)
151 * or -1 if the child-program is not running.
153 int wait (int options=0);
154 /** closes both STDIN and STDOUT connections to/from
156 * With the output-interposer thread gone, the program
158 * used by \ref terminate()
161 /** write into child-program's STDIN
162 * @param d data to write
163 * @param len length of data to write, if it is 0 (zero), d.length() is
164 * used to determine the number of bytes to transmit.
165 * @return number of bytes written.
167 int write_to_stdin (std::string d, size_t len=0);
169 /** The ReadStdout signal is emitted when the application writes to STDOUT.
170 * it passes the written data and its length in bytes as arguments to the bound
173 #ifdef NOPBD /* outside ardour */
174 sigc::signal<void, std::string,size_t> ReadStdout;
176 PBD::Signal2<void, std::string,size_t> ReadStdout;
179 /** The Terminated signal is emitted when application terminates. */
180 #ifdef NOPBD /* outside ardour */
181 sigc::signal<void> Terminated;
183 PBD::Signal0<void> Terminated;
186 /** interposer to emit signal for writes to STDOUT/ERR.
188 * Thread that reads the stdout of the forked
189 * process and signal-sends it to the main thread.
190 * It also emits the Terminated() signal once
191 * the the forked process closes it's stdout.
193 * Note: it's actually 'private' function but used
194 * by the internal pthread, which only has a pointer
195 * to this instance and thus can only access public fn.
197 void output_interposer ();
200 std::string cmd; ///< path to command - set when creating the class
201 int nicelevel; ///< process nice level - defaults to 0
203 void make_argp(std::string);
204 void make_argp_escaped(std::string command, const std::map<char, std::string> subs);
211 #ifdef PLATFORM_WINDOWS
212 PROCESS_INFORMATION *pid;
217 void make_wargs(char **);
222 pthread_mutex_t write_lock;
224 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.
229 pthread_t thread_id_tt;
234 }; /* end namespace */
236 #endif /* _libpbd_system_exec_h_ */