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91b6eb11 | 1 | /* Capture output from a subprocess. |
04277e02 | 2 | Copyright (C) 2017-2019 Free Software Foundation, Inc. |
91b6eb11 FW |
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 | <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #include <support/capture_subprocess.h> | |
20 | ||
21 | #include <errno.h> | |
22 | #include <stdlib.h> | |
23 | #include <support/check.h> | |
24 | #include <support/xunistd.h> | |
25 | #include <support/xsocket.h> | |
26 | ||
27 | static void | |
28 | transfer (const char *what, struct pollfd *pfd, struct xmemstream *stream) | |
29 | { | |
30 | if (pfd->revents != 0) | |
31 | { | |
32 | char buf[1024]; | |
33 | ssize_t ret = TEMP_FAILURE_RETRY (read (pfd->fd, buf, sizeof (buf))); | |
34 | if (ret < 0) | |
35 | { | |
36 | support_record_failure (); | |
37 | printf ("error: reading from subprocess %s: %m", what); | |
38 | pfd->events = 0; | |
39 | pfd->revents = 0; | |
40 | } | |
41 | else if (ret == 0) | |
42 | { | |
43 | /* EOF reached. Stop listening. */ | |
44 | pfd->events = 0; | |
45 | pfd->revents = 0; | |
46 | } | |
47 | else | |
48 | /* Store the data just read. */ | |
49 | TEST_VERIFY (fwrite (buf, ret, 1, stream->out) == 1); | |
50 | } | |
51 | } | |
52 | ||
53 | struct support_capture_subprocess | |
54 | support_capture_subprocess (void (*callback) (void *), void *closure) | |
55 | { | |
56 | struct support_capture_subprocess result; | |
57 | xopen_memstream (&result.out); | |
58 | xopen_memstream (&result.err); | |
59 | ||
60 | int stdout_pipe[2]; | |
61 | xpipe (stdout_pipe); | |
02cd5c1a FW |
62 | TEST_VERIFY (stdout_pipe[0] > STDERR_FILENO); |
63 | TEST_VERIFY (stdout_pipe[1] > STDERR_FILENO); | |
91b6eb11 FW |
64 | int stderr_pipe[2]; |
65 | xpipe (stderr_pipe); | |
02cd5c1a FW |
66 | TEST_VERIFY (stderr_pipe[0] > STDERR_FILENO); |
67 | TEST_VERIFY (stderr_pipe[1] > STDERR_FILENO); | |
91b6eb11 FW |
68 | |
69 | TEST_VERIFY (fflush (stdout) == 0); | |
70 | TEST_VERIFY (fflush (stderr) == 0); | |
71 | ||
72 | pid_t pid = xfork (); | |
73 | if (pid == 0) | |
74 | { | |
75 | xclose (stdout_pipe[0]); | |
76 | xclose (stderr_pipe[0]); | |
77 | xdup2 (stdout_pipe[1], STDOUT_FILENO); | |
78 | xdup2 (stderr_pipe[1], STDERR_FILENO); | |
02cd5c1a FW |
79 | xclose (stdout_pipe[1]); |
80 | xclose (stderr_pipe[1]); | |
91b6eb11 FW |
81 | callback (closure); |
82 | _exit (0); | |
83 | } | |
84 | xclose (stdout_pipe[1]); | |
85 | xclose (stderr_pipe[1]); | |
86 | ||
87 | struct pollfd fds[2] = | |
88 | { | |
89 | { .fd = stdout_pipe[0], .events = POLLIN }, | |
90 | { .fd = stderr_pipe[0], .events = POLLIN }, | |
91 | }; | |
92 | ||
93 | do | |
94 | { | |
95 | xpoll (fds, 2, -1); | |
96 | transfer ("stdout", &fds[0], &result.out); | |
97 | transfer ("stderr", &fds[1], &result.err); | |
98 | } | |
99 | while (fds[0].events != 0 || fds[1].events != 0); | |
100 | xclose (stdout_pipe[0]); | |
101 | xclose (stderr_pipe[0]); | |
102 | ||
103 | xfclose_memstream (&result.out); | |
104 | xfclose_memstream (&result.err); | |
105 | xwaitpid (pid, &result.status, 0); | |
106 | return result; | |
107 | } | |
108 | ||
109 | void | |
110 | support_capture_subprocess_free (struct support_capture_subprocess *p) | |
111 | { | |
112 | free (p->out.buffer); | |
113 | free (p->err.buffer); | |
114 | } |