GNU Octave  3.8.0
A high-level interpreted language, primarily intended for numerical computations, mostly compatible with Matlab
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oct-procbuf.cc
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1 /*
2 
3 Copyright (C) 1996-2013 John W. Eaton
4 
5 This file is part of Octave.
6 
7 Octave is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 3 of the License, or (at your
10 option) any later version.
11 
12 Octave is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along with Octave; see the file COPYING. If not, see
19 <http://www.gnu.org/licenses/>.
20 
21 */
22 
23 #ifdef HAVE_CONFIG_H
24 #include <config.h>
25 #endif
26 
27 #include <cerrno>
28 
29 #include <iostream>
30 
31 #include <sys/types.h>
32 #include <unistd.h>
33 
34 #include "lo-mappers.h"
35 #include "lo-utils.h"
36 #include "oct-procbuf.h"
37 #include "oct-syscalls.h"
38 #include "sysdep.h"
39 #include "variables.h"
40 
41 #include "defun.h"
42 #include "gripes.h"
43 #include "utils.h"
44 
45 #ifndef SHELL_PATH
46 #define SHELL_PATH "/bin/sh"
47 #endif
48 
49 // This class is based on the procbuf class from libg++, written by
50 // Per Bothner, Copyright (C) 1993 Free Software Foundation.
51 
53 
54 #ifndef BUFSIZ
55 #define BUFSIZ 1024
56 #endif
57 
59 octave_procbuf::open (const char *command, int mode)
60 {
61 #if defined (__CYGWIN__) || defined (__MINGW32__) || defined (_MSC_VER)
62 
63  if (is_open ())
64  return 0;
65 
66  f = octave_popen (command, (mode & std::ios::in) ? "r" : "w");
67 
68  if (! f)
69  return 0;
70 
71  // Oops... popen doesn't return the associated pid, so fake it for now
72 
73  proc_pid = 1;
74 
75  open_p = true;
76 
77  if (mode & std::ios::out)
78  ::setvbuf (f, 0, _IOLBF, BUFSIZ);
79 
80  return this;
81 
82 #elif defined (HAVE_SYS_WAIT_H)
83 
84  int pipe_fds[2];
85 
86  volatile int child_std_end = (mode & std::ios::in) ? 1 : 0;
87 
88  volatile int parent_end, child_end;
89 
90  if (is_open ())
91  return 0;
92 
93  if (pipe (pipe_fds) < 0)
94  return 0;
95 
96  if (mode & std::ios::in)
97  {
98  parent_end = pipe_fds[0];
99  child_end = pipe_fds[1];
100  }
101  else
102  {
103  parent_end = pipe_fds[1];
104  child_end = pipe_fds[0];
105  }
106 
107  proc_pid = ::fork ();
108 
109  if (proc_pid == 0)
110  {
111  gnulib::close (parent_end);
112 
113  if (child_end != child_std_end)
114  {
115  gnulib::dup2 (child_end, child_std_end);
116  gnulib::close (child_end);
117  }
118 
119  while (octave_procbuf_list)
120  {
121  FILE *fp = octave_procbuf_list->f;
122 
123  if (fp)
124  {
125  gnulib::fclose (fp);
126  fp = 0;
127  }
128 
129  octave_procbuf_list = octave_procbuf_list->next;
130  }
131 
132  execl (SHELL_PATH, "sh", "-c", command, static_cast<void *> (0));
133 
134  exit (127);
135  }
136 
137  gnulib::close (child_end);
138 
139  if (proc_pid < 0)
140  {
141  gnulib::close (parent_end);
142  return 0;
143  }
144 
145  f = ::fdopen (parent_end, (mode & std::ios::in) ? "r" : "w");
146 
147  if (mode & std::ios::out)
148  ::setvbuf (f, 0, _IOLBF, BUFSIZ);
149 
150  open_p = true;
151 
153  octave_procbuf_list = this;
154 
155  return this;
156 
157 #else
158 
159  return 0;
160 
161 #endif
162 }
163 
166 {
167 #if defined (__CYGWIN__) || defined (__MINGW32__) || defined (_MSC_VER)
168 
169  if (f)
170  {
171  wstatus = octave_pclose (f);
172  f = 0;
173  }
174 
175  open_p = false;
176 
177  return this;
178 
179 #elif defined (HAVE_SYS_WAIT_H)
180 
181  if (f)
182  {
183  pid_t wait_pid;
184 
185  int status = -1;
186 
187  for (octave_procbuf **ptr = &octave_procbuf_list;
188  *ptr != 0;
189  ptr = &(*ptr)->next)
190  {
191  if (*ptr == this)
192  {
193  *ptr = (*ptr)->next;
194  status = 0;
195  break;
196  }
197  }
198 
199  if (status == 0 && gnulib::fclose (f) == 0)
200  {
201  using namespace std;
202 
203  do
204  {
205  wait_pid = octave_syscalls::waitpid (proc_pid, &wstatus, 0);
206  }
207  while (wait_pid == -1 && errno == EINTR);
208  }
209 
210  f = 0;
211  }
212 
213  open_p = false;
214 
215  return this;
216 
217 #else
218 
219  return 0;
220 
221 #endif
222 }