2 * UCW Library -- Logging to Files
4 * (c) 1997--2009 Martin Mares <mj@ucw.cz>
5 * (c) 2008 Tomas Gavenciak <gavento@ucw.cz>
7 * This software may be freely distributed and used according to the terms
8 * of the GNU Lesser General Public License.
14 #include "ucw/threads.h"
15 #include "ucw/simple-lists.h"
24 struct log_stream ls; // ls.name is the current name of the log file
27 char *orig_name; // Original name with strftime escapes
31 FF_FORMAT_NAME = 1, // Name contains strftime escapes
32 FF_CLOSE_FD = 2, // Close the fd with the stream
33 FF_FD2_FOLLOWS = 4, // Maintain stderr as a clone of this stream
36 #define MAX_EXPAND 64 // Maximum size of expansion of strftime escapes
38 static int log_switch_nest;
41 do_log_reopen(struct file_stream *fs, const char *name)
43 int fd = ucw_open(name, O_WRONLY | O_CREAT | O_APPEND, 0666);
45 die("Unable to open log file %s: %m", name);
49 if (fs->flags & FF_FD2_FOLLOWS)
54 fs->ls.name = NULL; // We have to keep the stream consistent -- die() below can invoke logging
56 fs->ls.name = xstrdup(name);
60 do_log_switch(struct file_stream *fs, struct tm *tm)
62 if (!(fs->flags & FF_FORMAT_NAME))
68 do_log_reopen(fs, fs->orig_name);
73 int buflen = strlen(fs->orig_name) + MAX_EXPAND;
78 if (!log_switch_nest) // Avoid infinite loops if we die when switching logs
81 int l = strftime(name, buflen, fs->orig_name, tm);
82 if (l < 0 || l >= buflen)
83 die("Error formatting log file name: %m");
84 if (!fs->ls.name || strcmp(name, fs->ls.name))
86 do_log_reopen(fs, name);
95 /* destructor for standard files */
97 file_close(struct log_stream *ls)
99 struct file_stream *fs = (struct file_stream *) ls;
100 if ((fs->flags & FF_CLOSE_FD) && fs->fd >= 0)
103 xfree(fs->orig_name);
106 /* handler for standard files */
108 file_handler(struct log_stream *ls, struct log_msg *m)
110 struct file_stream *fs = (struct file_stream *) ls;
111 if ((fs->flags & FF_FORMAT_NAME) && m->tm)
112 do_log_switch(fs, m->tm);
114 int r = write(fs->fd, m->m, m->m_len);
115 /* FIXME: check for errors here? */
119 /* assign log to a file descriptor */
120 /* initialize with the default formatting, does NOT close the descriptor */
124 struct log_stream *ls = log_new_stream(sizeof(struct file_stream));
125 struct file_stream *fs = (struct file_stream *) ls;
127 ls->msgfmt = LSFMT_DEFAULT;
128 ls->handler = file_handler;
129 ls->close = file_close;
130 ls->name = xmalloc(16);
131 snprintf(ls->name, 16, "fd%d", fd);
135 static struct log_stream *
136 do_log_new_file(const char *path, uns more_flags)
138 struct log_stream *ls = log_new_stream(sizeof(struct file_stream));
139 struct file_stream *fs = (struct file_stream *) ls;
141 fs->orig_name = xstrdup(path);
142 if (strchr(path, '%'))
143 fs->flags = FF_FORMAT_NAME;
144 fs->flags |= FF_CLOSE_FD | more_flags;
145 ls->msgfmt = LSFMT_DEFAULT;
146 ls->handler = file_handler;
147 ls->close = file_close;
149 time_t now = time(NULL);
150 struct tm *tm = localtime(&now);
152 do_log_switch(fs, tm); // die()'s on errors
156 /* open() a file (append mode) */
157 /* initialize with the default formatting */
159 log_new_file(const char *path)
161 return do_log_new_file(path, 0);
167 time_t now = time(NULL);
168 struct tm *tm = localtime(&now);
172 for (int i=0; i < log_streams_after; i++)
173 if (log_streams.ptr[i]->handler == file_handler)
174 switched |= do_log_switch((struct file_stream *) log_streams.ptr[i], tm);
179 log_switch_disable(void)
185 log_switch_enable(void)
187 ASSERT(log_switch_nest);
191 /* Emulate the old single-file interface: close the existing log file and open a new one. */
193 log_file(const char *name)
198 struct log_stream *ls = do_log_new_file(name, FF_FD2_FOLLOWS);
199 struct log_stream *def = log_stream_by_flags(0);
200 log_rm_substream(def, NULL);
201 log_add_substream(def, ls);
206 int main(int argc, char **argv)
209 log_file("/proc/self/fd/1");
210 // struct log_stream *ls = log_new_fd(1);
211 // struct log_stream *ls = log_new_file("/tmp/quork-%Y%m%d-%H%M%S");
212 for (int i=1; i<argc; i++)
213 msg(L_INFO, argv[i]);