summaryrefslogtreecommitdiff
path: root/graphics/asymptote/pipestream.cc
blob: f7f3006c0144bd5c4b87122291585ed70f8848c5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/* Pipestream: A simple C++ interface to UNIX pipes
   Copyright (C) 2005-2014 John C. Bowman,
   with contributions from Mojca Miklavec

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */

#include <iostream>
#include <cstring>
#include <cerrno>
#include <sstream>
#include <signal.h>

#include "pipestream.h"
#include "common.h"
#include "errormsg.h"
#include "settings.h"
#include "util.h"
#include "interact.h"
#include "lexical.h"
#include "camperror.h"
#include "pen.h"

void iopipestream::open(const mem::vector<string> &command, const char *hint,
                        const char *application, int out_fileno)
{
  if(pipe(in) == -1) {
    ostringstream buf;
    buf << "in pipe failed: ";
    for(size_t i=0; i < command.size(); ++i) buf << command[i];
    camp::reportError(buf);
  }

  if(pipe(out) == -1) {
    ostringstream buf;
    buf << "out pipe failed: ";
    for(size_t i=0; i < command.size(); ++i) buf << command[i];
    camp::reportError(buf);
  }
  cout.flush(); // Flush stdout to avoid duplicate output.

  if((pid=fork()) < 0) {
    ostringstream buf;
    buf << "fork failed: ";
    for(size_t i=0; i < command.size(); ++i) buf << command[i];
    camp::reportError(buf);
  }

  if(pid == 0) {
    if(interact::interactive) signal(SIGINT,SIG_IGN);
    close(in[1]);
    close(out[0]);
    close(STDIN_FILENO);
    close(out_fileno);
    dup2(in[0],STDIN_FILENO);
    dup2(out[1],out_fileno);
    close(in[0]);
    close(out[1]);
    char **argv=args(command);
    if(argv) execvp(argv[0],argv);
    execError(argv[0],hint,application);
    kill(0,SIGTERM);
    _exit(-1);
  }
  close(out[1]);
  close(in[0]);
  *buffer=0;
  pipeopen=true;
  pipein=true;
  Running=true;
  block(false,true);
}

void iopipestream::eof()
{
  if(pipeopen && pipein) {
    close(in[1]);
    pipein=false;
  }
}

void iopipestream::pipeclose()
{
  if(pipeopen) {
    kill(pid,SIGHUP);
    eof();
    close(out[0]);
    Running=false;
    pipeopen=false;
    waitpid(pid,NULL,0); // Avoid zombies.
  }
}

void iopipestream::block(bool write, bool read)
{
  if(pipeopen) {
    int w=fcntl(in[1],F_GETFL);
    int r=fcntl(out[0],F_GETFL);
    fcntl(in[1],F_SETFL,write ? w & ~O_NONBLOCK : w | O_NONBLOCK);
    fcntl(out[0],F_SETFL,read ? r & ~O_NONBLOCK : r | O_NONBLOCK);
  }
}

ssize_t iopipestream::readbuffer()
{
  ssize_t nc;
  char *p=buffer;
  ssize_t size=BUFSIZE-1;
  errno=0;
  for(;;) {
    if((nc=read(out[0],p,size)) < 0) {
      if(errno == EAGAIN || errno == EINTR) {p[0]=0; break;}
     else {
       ostringstream buf;
       buf << "read from pipe failed: errno=" << errno;
       camp::reportError(buf);
      }
      nc=0;
    }
    p[nc]=0;
    if(nc == 0) {
      if(waitpid(pid,NULL,WNOHANG) == pid)
        Running=false;
      break;
    }
    if(nc > 0) {
      if(settings::verbose > 2) cerr << p;
      break;
    }
  }
  return nc;
}

bool iopipestream::tailequals(const char *buf, size_t len, const char *prompt,
                              size_t plen)
{
  const char *a=buf+len;
  const char *b=prompt+plen;
  while(b >= prompt) {
    if(a < buf) return false;
    if(*a != *b) return false;
    // Handle MSDOS incompatibility:
    if(a > buf && *a == '\n' && *(a-1) == '\r') --a;
    --a; --b;
  }
  return true;
}

string iopipestream::readline()
{
  sbuffer.clear();
  int nc;
  do {
    nc=readbuffer();
    sbuffer.append(buffer);
  } while(buffer[nc-1] != '\n' && Running);
  return sbuffer;
}

void iopipestream::wait(const char *prompt)
{
  sbuffer.clear();
  size_t plen=strlen(prompt);

  do {
    readbuffer();
    sbuffer.append(buffer);
  } while(!tailequals(sbuffer.c_str(),sbuffer.size(),prompt,plen));
}

int iopipestream::wait()
{
  for(;;) {
    int status;
    if (waitpid(pid,&status,0) == -1) {
      if (errno == ECHILD) return 0;
      if (errno != EINTR) {
        ostringstream buf;
        buf << "Process " << pid << " failed";
        camp::reportError(buf);
      }
    } else {
      if(WIFEXITED(status)) return WEXITSTATUS(status);
      else {
        ostringstream buf;
        buf << "Process " << pid << " exited abnormally";
        camp::reportError(buf);
      }
    }
  }
}

void iopipestream::Write(const string &s)
{
  ssize_t size=s.length();
  if(settings::verbose > 2) cerr << s;
  if(write(in[1],s.c_str(),size) != size) {
    camp::reportFatal("write to pipe failed");
  }
}