1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
2 // vim: ts=8 sw=2 smarttab
3 /*
4 * Ceph - scalable distributed file system
5 *
6 * Copyright (C) 2011 New Dream Network
7 *
8 * This is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License version 2.1, as published by the Free Software
11 * Foundation. See file COPYING.
12 *
13 */
14
15 #include "common/errno.h"
16
17 #include <sstream>
18 #include <stdarg.h>
19 #include <sys/wait.h>
20 #include <unistd.h>
21 #include <vector>
22
23 using std::ostringstream;
24
25 std::string run_cmd(const char *cmd, ...)
26 {
27 std::vector <const char *> arr;
28 va_list ap;
29 va_start(ap, cmd);
30 const char *c = cmd;
31 do {
32 arr.push_back(c);
33 c = va_arg(ap, const char*);
34 } while (c != NULL);
35 va_end(ap);
36 arr.push_back(NULL);
37
38 int fret = fork();
39 if (fret == -1) {
40 int err = errno;
41 ostringstream oss;
42 oss << "run_cmd(" << cmd << "): unable to fork(): " << cpp_strerror(err);
43 return oss.str();
44 }
45 else if (fret == 0) {
46 // execvp doesn't modify its arguments, so the const-cast here is safe.
47 close(STDIN_FILENO);
48 close(STDOUT_FILENO);
49 close(STDERR_FILENO);
50 execvp(cmd, (char * const*)&arr[0]);
51 _exit(127);
52 }
53 int status;
54 while (waitpid(fret, &status, 0) == -1) {
55 int err = errno;
56 if (err == EINTR)
57 continue;
58 ostringstream oss;
59 oss << "run_cmd(" << cmd << "): waitpid error: "
60 << cpp_strerror(err);
61 return oss.str();
62 }
63 if (WIFEXITED(status)) {
64 int wexitstatus = WEXITSTATUS(status);
65 if (wexitstatus != 0) {
66 ostringstream oss;
67 oss << "run_cmd(" << cmd << "): exited with status " << wexitstatus;
68 return oss.str();
69 }
70 return "";
71 }
72 else if (WIFSIGNALED(status)) {
73 ostringstream oss;
74 oss << "run_cmd(" << cmd << "): terminated by signal";
75 return oss.str();
76 }
77 ostringstream oss;
78 oss << "run_cmd(" << cmd << "): terminated by unknown mechanism";
79 return oss.str();
80 }
81