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1 #include <iostream> |
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2 #include <unistd.h> |
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3 #include <spawn.h> |
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4 #include <cstring> |
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5 #include <string> |
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6 #include <sys/wait.h> |
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7 extern char** environ; |
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8 std::string run_piped(const char* path, char* const argv[], const std::string& input) |
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9 { |
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10 int status; |
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11 pid_t pid; |
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12 int pipeA[2]; |
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13 int pipeB[2]; |
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14 pipe(pipeA); |
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15 pipe(pipeB); |
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16 posix_spawn_file_actions_t actions; |
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17 posix_spawn_file_actions_init(&actions); // initialize actions |
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18 posix_spawn_file_actions_adddup2(&actions, pipeA[0], STDIN_FILENO); |
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19 posix_spawn_file_actions_adddup2(&actions, pipeB[1], STDOUT_FILENO); |
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20 posix_spawn_file_actions_addclose(&actions, pipeA[1]); // closes write end in child |
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21 posix_spawn_file_actions_addclose(&actions, pipeB[0]); // makes sure child doesn't read its own output pipe |
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22 posix_spawn_file_actions_addclose(&actions, pipeA[0]); // close read fd in child |
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23 posix_spawn_file_actions_addclose(&actions, pipeB[1]); // close read fd in child, part 2 |
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24 std::cout << "Running posix_spawn()..." << std::endl; |
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25 status = posix_spawn(&pid, path, &actions, NULL, const_cast<char* const*>(argv), environ); |
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26 close(pipeA[0]); |
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27 close(pipeB[1]); |
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28 if (status != 0) { |
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29 posix_spawn_file_actions_destroy(&actions); |
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30 close(pipeA[1]); |
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31 close(pipeB[0]); |
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32 std::cerr << "posix_spawn failed: " << strerror(status) << std::endl; |
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33 return "error"; |
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34 } |
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35 write(pipeA[1],input.c_str(), input.size()); |
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36 close(pipeA[1]); |
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37 char buf[256]; |
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38 std::string result; |
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39 ssize_t n; |
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40 while ((n = read(pipeB[0], buf, sizeof(buf))) > 0) { |
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41 result.append(buf, n); |
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42 } |
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43 close(pipeB[0]); |
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44 if (waitpid(pid, &status, 0) == -1) { |
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45 posix_spawn_file_actions_destroy(&actions); |
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46 close(pipeA[1]); |
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47 close(pipeB[0]); |
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48 perror("waitpid"); |
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49 return "error"; |
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50 } |
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51 return result; |
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52 } |
