1 /* system/core/include/logwrap/logwrap.h
2 *
3 * Copyright 2013, The Android Open Source Project
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 #ifndef __LIBS_LOGWRAP_H
19 #define __LIBS_LOGWRAP_H
20
21 #include <stdbool.h>
22 #include <stdint.h>
23
24 __BEGIN_DECLS
25
26 /*
27 * Run a command while logging its stdout and stderr
28 *
29 * WARNING: while this function is running it will clear all SIGCHLD handlers
30 * if you rely on SIGCHLD in the caller there is a chance zombies will be
31 * created if you're not calling waitpid after calling this. This function will
32 * log a warning when it clears SIGCHLD for processes other than the child it
33 * created.
34 *
35 * Arguments:
36 * argc: the number of elements in argv
37 * argv: an array of strings containing the command to be executed and its
38 * arguments as separate strings. argv does not need to be
39 * NULL-terminated
40 * status: the equivalent child status as populated by wait(status). This
41 * value is only valid when logwrap successfully completes. If NULL
42 * the return value of the child will be the function's return value.
43 * ignore_int_quit: set to true if you want to completely ignore SIGINT and
44 * SIGQUIT while logwrap is running. This may force the end-user to
45 * send a signal twice to signal the caller (once for the child, and
46 * once for the caller)
47 * log_target: Specify where to log the output of the child, either LOG_NONE,
48 * LOG_ALOG (for the Android system log), LOG_KLOG (for the kernel
49 * log), or LOG_FILE (and you need to specify a pathname in the
50 * file_path argument, otherwise pass NULL). These are bit fields,
51 * and can be OR'ed together to log to multiple places.
52 * abbreviated: If true, capture up to the first 100 lines and last 4K of
53 * output from the child. The abbreviated output is not dumped to
54 * the specified log until the child has exited.
55 * file_path: if log_target has the LOG_FILE bit set, then this parameter
56 * must be set to the pathname of the file to log to.
57 * unused_opts: currently unused.
58 * unused_opts_len: currently unused.
59 *
60 * Return value:
61 * 0 when logwrap successfully run the child process and captured its status
62 * -1 when an internal error occurred
63 * -ECHILD if status is NULL and the child didn't exit properly
64 * the return value of the child if it exited properly and status is NULL
65 *
66 */
67
68 /* Values for the log_target parameter android_fork_execvp_ext() */
69 #define LOG_NONE 0
70 #define LOG_ALOG 1
71 #define LOG_KLOG 2
72 #define LOG_FILE 4
73
74 // TODO: Remove unused_opts / unused_opts_len in a followup change.
75 int android_fork_execvp_ext(int argc, char* argv[], int *status, bool ignore_int_quit,
76 int log_target, bool abbreviated, char *file_path, void* unused_opts,
77 int unused_opts_len);
78
79 /* Similar to above, except abbreviated logging is not available, and if logwrap
80 * is true, logging is to the Android system log, and if false, there is no
81 * logging.
82 */
android_fork_execvp(int argc,char * argv[],int * status,bool ignore_int_quit,bool logwrap)83 static inline int android_fork_execvp(int argc, char* argv[], int *status,
84 bool ignore_int_quit, bool logwrap)
85 {
86 return android_fork_execvp_ext(argc, argv, status, ignore_int_quit,
87 (logwrap ? LOG_ALOG : LOG_NONE), false, NULL,
88 NULL, 0);
89 }
90
91 __END_DECLS
92
93 #endif /* __LIBS_LOGWRAP_H */
94