|
5
|
|
|
|
|
|
|
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include "date.h"
/* length of a string like "Sun, 08-Jan-2006 13:56:17 GMT"]" */
#define DATE_FORMAT_LEN 29
double date_compute(const char *date, int len)
{
int state = 0;
int negative = -1;
int part[2] = {0,0};
int p = 0;
double decimals = 1;
char term = 's';
int e = 0;
double offset = 0.0;
time_t base = 0;
if (len < 0) {
len = strlen(date);
}
if (len <= 0) {
return -1;
}
/* special case when date is the string "now" */
if (len == 3 &&
date[0] == 'n' &&
date[1] == 'o' &&
date[2] == 'w') {
return time(0);
}
for (; e < len; ++e) {
char c = date[e];
if (isspace(c)) {
if (state > 0) {
return -1;
}
continue;
} else if (c == '+') {
if (state >= 1) {
return -1;
}
state = 1;
negative = 0;
} else if (c == '-') {
if (state >= 1) {
return -1;
}
state = 1;
negative = 1;
} else if (isdigit(c)) {
if (state > 2) {
return -1;
}
state = 2;
part[p] = 10 * part[p] + c - '0';
if (p > 0) {
decimals *= 10;
}
} else if (c == '.') {
if (state > 2) {
return -1;
}
if (p >= 1) {
return -1;
}
state = 2;
++p;
} else if (c == 'y' ||
c == 'M' ||
c == 'd' ||
c == 'h' ||
c == 'm' ||
c == 's') {
if (state >= 3) {
return -1;
}
state = 3;
term = c;
} else {
return -1;
}
}
/* We require at least a number */
if (state < 2) {
return -1;
}
offset = (double) part[0];
/* digits only => epoch */
if (state == 2 && negative < 0) {
return offset;
}
offset += (double) part[1] / decimals;
if (negative == 1) {
offset = - offset;
}
switch (term) {
case 'y':
offset *= 24 * 60 * 60 * 365;
break;
case 'M':
offset *= 24 * 60 * 60 * 30;
break;
case 'd':
offset *= 24 * 60 * 60;
break;
case 'h':
offset *= 60 * 60;
break;
case 'm':
offset *= 60;
break;
case 's':
default:
break;
}
base = time(0);
/* printf("time now %lu\n", (unsigned long) base); */
return base + offset;
}
Buffer* date_format(double date, Buffer* format)
{
static const char* Mon[] = {
"Jan",
"Feb",
"Mar",
"Apr",
"May",
"Jun",
"Jul",
"Aug",
"Sep",
"Oct",
"Nov",
"Dec",
};
static const char* Day[] = {
"Sun",
"Mon",
"Tue",
"Wed",
"Thu",
"Fri",
"Sat",
};
time_t t = (time_t) date;
struct tm gmt;
#if defined(_WIN32) || defined(_WIN64)
/* Damn you Windows... */
struct tm* p = gmtime(&t);
if (p) {
gmt = *p;
} else {
memset(&gmt, 0, sizeof(gmt));
}
#else
gmtime_r(&t, &gmt);
#endif
buffer_ensure_unused(format, DATE_FORMAT_LEN);
sprintf(format->data + format->wpos,
"%3s, %02d-%3s-%04d %02d:%02d:%02d %3s",
Day[gmt.tm_wday % 7],
gmt.tm_mday,
Mon[gmt.tm_mon % 12],
gmt.tm_year + 1900,
gmt.tm_hour,
gmt.tm_min,
gmt.tm_sec,
"GMT");
format->wpos += DATE_FORMAT_LEN;
return format;
} |