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Quieten over-pick compiler.
[disorder] / lib / log.c
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460b9539 1/*
2 * This file is part of DisOrder.
5aff007d 3 * Copyright (C) 2004-2008 Richard Kettlewell
460b9539 4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
18 * USA
19 */
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20/** @file lib/log.c @brief Errors and logging
21 *
22 * All messages are initially emitted by one of the four functions below.
23 * debug() is generally invoked via D() so that mostly you just do a test
24 * rather than a complete subroutine call.
25 *
26 * Messages are dispatched via @ref log_default. This defaults to @ref
27 * log_stderr. daemonize() will turn off @ref log_stderr and use @ref
28 * log_syslog instead.
29 *
30 * fatal() will call exitfn() with a nonzero status. The default value is
31 * exit(), but it should be set to _exit() anywhere but the 'main line' of the
32 * program, to guarantee that exit() gets called at most once.
33 */
460b9539 34
35#define NO_MEMORY_ALLOCATION
36/* because the memory allocation functions report errors */
37
38#include <config.h>
39
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <errno.h>
44#include <syslog.h>
45#include <sys/time.h>
46
47#include "log.h"
48#include "disorder.h"
49#include "printf.h"
50
14ad73b9 51/** @brief Definition of a log output */
460b9539 52struct log_output {
14ad73b9 53 /** @brief Function to call */
460b9539 54 void (*fn)(int pri, const char *msg, void *user);
14ad73b9 55 /** @brief User data */
460b9539 56 void *user;
57};
58
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59/** @brief Function to call on a fatal error
60 *
61 * This is normally @c exit() but in the presence of @c fork() it
62 * sometimes gets set to @c _exit(). */
460b9539 63void (*exitfn)(int) attribute((noreturn)) = exit;
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64
65/** @brief Debug flag */
460b9539 66int debugging;
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67
68/** @brief Program name */
460b9539 69const char *progname;
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70
71/** @brief Filename for debug messages */
460b9539 72const char *debug_filename;
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73
74/** @brief Line number for debug messages */
460b9539 75int debug_lineno;
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76
77/** @brief Pointer to chosen log output structure */
460b9539 78struct log_output *log_default = &log_stderr;
79
14ad73b9 80/** @brief Filename to debug for */
460b9539 81static const char *debug_only;
82
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83/** @brief Construct log line, encoding special characters
84 *
85 * We might be receiving things in any old encoding, or binary rubbish
86 * in no encoding at all, so escape anything we don't like the look
87 * of. We limit the log message to a kilobyte.
88 */
460b9539 89static void format(char buffer[], size_t bufsize, const char *fmt, va_list ap) {
90 char t[1024];
91 const char *p;
92 int ch;
93 size_t n = 0;
94
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95 if(byte_vsnprintf(t, sizeof t, fmt, ap) < 0) {
96 strcpy(t, "[byte_vsnprintf failed: ");
97 strncat(t, fmt, sizeof t - strlen(t) - 1);
98 }
460b9539 99 p = t;
100 while((ch = (unsigned char)*p++)) {
101 if(ch >= ' ' && ch <= 126) {
102 if(n < bufsize) buffer[n++] = ch;
103 } else {
104 if(n < bufsize) buffer[n++] = '\\';
105 if(n < bufsize) buffer[n++] = '0' + ((ch >> 6) & 7);
106 if(n < bufsize) buffer[n++] = '0' + ((ch >> 3) & 7);
107 if(n < bufsize) buffer[n++] = '0' + ((ch >> 0) & 7);
108 }
109 }
110 if(n >= bufsize)
111 n = bufsize - 1;
112 buffer[n] = 0;
113}
114
14ad73b9 115/** @brief Log to a file
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116 * @param pri Message priority (as per syslog)
117 * @param msg Messagge to log
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118 * @param user The @c FILE @c * to log to or NULL for @c stderr
119 */
460b9539 120static void logfp(int pri, const char *msg, void *user) {
121 struct timeval tv;
122 FILE *fp = user ? user : stderr;
123 /* ...because stderr is not a constant so we can't initialize log_stderr
124 * sanely */
125 const char *p;
126
127 if(progname)
128 fprintf(fp, "%s: ", progname);
129 if(pri <= LOG_ERR)
130 fputs("ERROR: ", fp);
131 else if(pri < LOG_DEBUG)
132 fputs("INFO: ", fp);
133 else {
134 if(!debug_only) {
135 if(!(debug_only = getenv("DISORDER_DEBUG_ONLY")))
136 debug_only = "";
137 }
138 gettimeofday(&tv, 0);
139 p = debug_filename;
140 while(!strncmp(p, "../", 3)) p += 3;
141 if(*debug_only && strcmp(p, debug_only))
142 return;
143 fprintf(fp, "%llu.%06lu: %s:%d: ",
144 (unsigned long long)tv.tv_sec, (unsigned long)tv.tv_usec,
145 p, debug_lineno);
146 }
147 fputs(msg, fp);
148 fputc('\n', fp);
149}
150
14ad73b9 151/** @brief Log to syslog */
460b9539 152static void logsyslog(int pri, const char *msg,
153 void attribute((unused)) *user) {
154 if(pri < LOG_DEBUG)
155 syslog(pri, "%s", msg);
156 else
157 syslog(pri, "%s:%d: %s", debug_filename, debug_lineno, msg);
158}
159
14ad73b9 160/** @brief Log output that writes to @c stderr */
460b9539 161struct log_output log_stderr = { logfp, 0 };
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162
163/** @brief Log output that sends to syslog */
460b9539 164struct log_output log_syslog = { logsyslog, 0 };
165
14ad73b9 166/** @brief Format and log a message */
460b9539 167static void vlogger(int pri, const char *fmt, va_list ap) {
168 char buffer[1024];
169
170 format(buffer, sizeof buffer, fmt, ap);
171 log_default->fn(pri, buffer, log_default->user);
172}
173
14ad73b9 174/** @brief Format and log a message */
460b9539 175static void logger(int pri, const char *fmt, ...) {
176 va_list ap;
177
178 va_start(ap, fmt);
179 vlogger(pri, fmt, ap);
180 va_end(ap);
181}
182
14ad73b9 183/** @brief Format and log a message
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184 * @param pri Message priority (as per syslog)
185 * @param fmt Format string
14ad73b9 186 * @param errno_value Errno value to include as a string, or 0
840f3008 187 * @param ap Argument list
14ad73b9 188 */
460b9539 189void elog(int pri, int errno_value, const char *fmt, va_list ap) {
190 char buffer[1024];
191
192 if(errno_value == 0)
193 vlogger(pri, fmt, ap);
194 else {
195 memset(buffer, 0, sizeof buffer);
196 byte_vsnprintf(buffer, sizeof buffer, fmt, ap);
197 buffer[sizeof buffer - 1] = 0;
198 logger(pri, "%s: %s", buffer, strerror(errno_value));
199 }
200}
201
202#define disorder_fatal fatal
203#define disorder_error error
204#define disorder_info info
205
206/* shared implementation of vararg functions */
207#include "log-impl.h"
208
14ad73b9 209/** @brief Log a debug message */
460b9539 210void debug(const char *msg, ...) {
211 va_list ap;
212
213 va_start(ap, msg);
214 vlogger(LOG_DEBUG, msg, ap);
215 va_end(ap);
216}
217
14ad73b9 218/** @brief Set the program name from @c argc */
460b9539 219void set_progname(char **argv) {
220 if((progname = strrchr(argv[0], '/')))
221 ++progname;
222 else
223 progname = argv[0];
224}
225
226/*
227Local Variables:
228c-basic-offset:2
229comment-column:40
230End:
231*/