1/* Capture output from a subprocess.
2 Copyright (C) 2017-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef SUPPORT_CAPTURE_SUBPROCESS_H
20#define SUPPORT_CAPTURE_SUBPROCESS_H
21
22#include <support/xmemstream.h>
23
24struct support_capture_subprocess
25{
26 struct xmemstream out;
27 struct xmemstream err;
28 int status;
29};
30
31/* Invoke CALLBACK (CLOSURE) in a subprocess and capture standard
32 output, standard error, and the exit status. The out.buffer and
33 err.buffer members in the result are null-terminated strings which
34 can be examined by the caller (out.out and err.out are NULL). */
35struct support_capture_subprocess support_capture_subprocess
36 (void (*callback) (void *), void *closure);
37
38/* Issue FILE with ARGV arguments by using posix_spawn and capture standard
39 output, standard error, and the exit status. The out.buffer and err.buffer
40 are handle as support_capture_subprocess. */
41struct support_capture_subprocess support_capture_subprogram
42 (const char *file, char *const argv[]);
43
44/* Copy the running program into a setgid binary and run it with CHILD_ID
45 argument. If execution is successful, return the exit status of the child
46 program, otherwise return a non-zero failure exit code. */
47int support_capture_subprogram_self_sgid
48 (char *child_id);
49
50/* Deallocate the subprocess data captured by
51 support_capture_subprocess. */
52void support_capture_subprocess_free (struct support_capture_subprocess *);
53
54enum support_capture_allow
55{
56 /* No output is allowed. */
57 sc_allow_none = 0x01,
58 /* Output to stdout is permitted. */
59 sc_allow_stdout = 0x02,
60 /* Output to standard error is permitted. */
61 sc_allow_stderr = 0x04,
62};
63
64/* Check that the subprocess exited and that only the allowed outputs
65 happened. If STATUS_OR_SIGNAL is nonnegative, it is the expected
66 (decoded) exit status of the process, as returned by WEXITSTATUS.
67 If STATUS_OR_SIGNAL is negative, -STATUS_OR_SIGNAL is the expected
68 termination signal, as returned by WTERMSIG. ALLOWED is a
69 combination of support_capture_allow flags. Report errors under
70 the CONTEXT message. */
71void support_capture_subprocess_check (struct support_capture_subprocess *,
72 const char *context,
73 int status_or_signal, int allowed)
74 __attribute__ ((nonnull (1, 2)));
75
76#endif /* SUPPORT_CAPTURE_SUBPROCESS_H */
77