error.c revision 6081 
1#include <stdio.h>
2#include <string.h>
3#include <stdarg.h>
4#include <time.h>
5#include "error.h"
6
7static FILE *error_fp = NULL;
8static char *prog = NULL;
9
10
11/*
12 * Log errors to the given file.
13 */
14void
15err_set_log(char *log_file)
16    {
17    FILE *fp;
18
19    if ((fp = fopen(log_file, "a")) == NULL)
20	err("cannot log to '%s'", log_file);
21    else
22	error_fp = fp;
23    }
24
25
26/*
27 * Set the error prefix if not logging to a file.
28 */
29void
30err_prog_name(char *name)
31    {
32    if ((prog = strrchr(name, '/')) == NULL)
33	prog = name;
34    else
35	prog++;
36    }
37
38
39/*
40 * Log an error.
41 */
42void
43err(char *fmt, ...)
44    {
45    va_list ap;
46    time_t now;
47    struct tm *tm;
48    FILE *fp;
49
50    if ((fp = error_fp) == NULL)
51	{
52	fp = stderr;
53	if (prog != NULL)
54	    fprintf(fp, "%s: ", prog);
55	}
56    else
57	{
58	time(&now);
59	tm = localtime(&now);
60	fprintf(fp, "%04d-%02d-%02d %02d:%02d ", tm->tm_year+1900,
61	    tm->tm_mon+1, tm->tm_mday, tm->tm_hour, tm->tm_min);
62	}
63
64    va_start(ap, fmt);
65    vfprintf(fp, fmt, ap);
66    va_end(ap);
67
68    fprintf(fp, "\n");
69    fflush(fp);
70    }
71