63 constexpr int READ = 0;  variable
274             CHECK_TRUE(CustomFdClose(fds[READ]) == 0, nullptr, "CustomFdClose failed!");  in CustomPopen()
279             dup2(fds[READ], STDIN_FILENO); // Redirect stdin to pipe  in CustomPopen()
280             CHECK_TRUE(CustomFdClose(fds[READ]) == 0, nullptr, "CustomFdClose failed!");  in CustomPopen()
298 …      CHECK_TRUE(CustomFdClose(fds[READ]) == 0, nullptr, "%s %d CustomFdClose failed! errno(%s)\n",  in CustomPopen()
307         return fdopen(fds[READ], "r");  in CustomPopen()
335         if (fileno(fp) == fds[READ]) {  in CustomPclose()
336             fds[READ] = -1;  in CustomPclose()
340             CHECK_TRUE(CustomFdClose(fds[READ]) == 0, -1, "CustomFdClose failed!");  in CustomPclose()
357     CHECK_TRUE(fds[READ] != -1 && fds[WRITE] != -1, -1, "END fds[READ/WRITE]=-1");  in CustomPUnblock()
359     int stat = fcntl(fds[READ], F_GETFL);  in CustomPUnblock()
366         fcntl(fds[READ], F_SETFL, O_NONBLOCK);  in CustomPUnblock()