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cal: small code shrink

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This commit is contained in:
Denis Vlasenko 2007-07-26 11:12:51 +00:00
parent 972fa099e6
commit 661f6fad77
1 changed files with 50 additions and 55 deletions
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105
coreutils/cal.c
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@ -19,6 +19,8 @@
#include "libbb.h" #include "libbb.h"
/* We often use "unsigned" intead of "int", it's easier to div on most CPUs */
#define THURSDAY 4 /* for reformation */ #define THURSDAY 4 /* for reformation */
#define SATURDAY 6 /* 1 Jan 1 was a Saturday */ #define SATURDAY 6 /* 1 Jan 1 was a Saturday */
@ -28,29 +30,25 @@
#define MAXDAYS 42 /* max slots in a month array */ #define MAXDAYS 42 /* max slots in a month array */
#define SPACE -1 /* used in day array */ #define SPACE -1 /* used in day array */
static const char days_in_month[] = { static const unsigned char days_in_month[] = {
0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
}; };
static const char sep1752[] = { static const unsigned char sep1752[] = {
1, 2, 14, 15, 16, 1, 2, 14, 15, 16,
17, 18, 19, 20, 21, 22, 23, 17, 18, 19, 20, 21, 22, 23,
24, 25, 26, 27, 28, 29, 30 24, 25, 26, 27, 28, 29, 30
}; };
static int julian; static unsigned julian;
/* leap year -- account for Gregorian reformation in 1752 */ /* leap year -- account for Gregorian reformation in 1752 */
#define leap_year(yr) \ static int leap_year(unsigned yr)
((yr) <= 1752 ? !((yr) % 4) : \
(!((yr) % 4) && ((yr) % 100)) || !((yr) % 400))
static int is_leap_year(int year)
{ {
return leap_year(year); if (yr <= 1752)
return !(yr % 4);
return (!(yr % 4) && (yr % 100)) || !(yr % 400);
} }
#undef leap_year
#define leap_year(yr) is_leap_year(yr)
/* number of centuries since 1700, not inclusive */ /* number of centuries since 1700, not inclusive */
#define centuries_since_1700(yr) \ #define centuries_since_1700(yr) \
@ -64,12 +62,12 @@ static int is_leap_year(int year)
#define leap_years_since_year_1(yr) \ #define leap_years_since_year_1(yr) \
((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr)) ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
static void center (char *, int, int); static void center(char *, unsigned, unsigned);
static void day_array (int, int, int *); static void day_array(unsigned, unsigned, unsigned *);
static void trim_trailing_spaces_and_print (char *); static void trim_trailing_spaces_and_print(char *);
static void blank_string(char *buf, size_t buflen); static void blank_string(char *buf, size_t buflen);
static char *build_row(char *p, int *dp); static char *build_row(char *p, unsigned *dp);
#define DAY_LEN 3 /* 3 spaces per day */ #define DAY_LEN 3 /* 3 spaces per day */
#define J_DAY_LEN (DAY_LEN + 1) #define J_DAY_LEN (DAY_LEN + 1)
@ -83,20 +81,18 @@ int cal_main(int argc, char **argv)
struct tm *local_time; struct tm *local_time;
struct tm zero_tm; struct tm zero_tm;
time_t now; time_t now;
int month, year, flags, i; unsigned month, year, flags, i;
char *month_names[12]; char *month_names[12];
char day_headings[28]; /* 28 for julian, 21 for nonjulian */ char day_headings[28]; /* 28 for julian, 21 for nonjulian */
char buf[40]; char buf[40];
flags = getopt32(argc, argv, "jy"); flags = getopt32(argc, argv, "jy");
julian = flags & 1; julian = flags & 1;
argv += optind;
month = 0; month = 0;
argv += optind;
argc -= optind;
if ((argc -= optind) > 2) { if (argc > 2) {
bb_show_usage(); bb_show_usage();
} }
@ -109,12 +105,12 @@ int cal_main(int argc, char **argv)
} }
} else { } else {
if (argc == 2) { if (argc == 2) {
month = xatoul_range(*argv++, 1, 12); month = xatou_range(*argv++, 1, 12);
} }
year = xatoul_range(*argv, 1, 9999); year = xatou_range(*argv, 1, 9999);
} }
blank_string(day_headings, sizeof(day_headings) - 7 + 7*julian); blank_string(day_headings, sizeof(day_headings) - 7 + 7*julian);
i = 0; i = 0;
do { do {
@ -130,8 +126,8 @@ int cal_main(int argc, char **argv)
} while (++i < 12); } while (++i < 12);
if (month) { if (month) {
int row, len, days[MAXDAYS]; unsigned row, len, days[MAXDAYS];
int *dp = days; unsigned *dp = days;
char lineout[30]; char lineout[30];
day_array(month, year, dp); day_array(month, year, dp);
@ -145,8 +141,8 @@ int cal_main(int argc, char **argv)
trim_trailing_spaces_and_print(lineout); trim_trailing_spaces_and_print(lineout);
} }
} else { } else {
int row, which_cal, week_len, days[12][MAXDAYS]; unsigned row, which_cal, week_len, days[12][MAXDAYS];
int *dp; unsigned *dp;
char lineout[80]; char lineout[80];
sprintf(lineout, "%d", year); sprintf(lineout, "%d", year);
@ -193,19 +189,21 @@ int cal_main(int argc, char **argv)
* out end to end. You would have 42 numbers or spaces. This routine * out end to end. You would have 42 numbers or spaces. This routine
* builds that array for any month from Jan. 1 through Dec. 9999. * builds that array for any month from Jan. 1 through Dec. 9999.
*/ */
static void day_array(int month, int year, int *days) static void day_array(unsigned month, unsigned year, unsigned *days)
{ {
long temp; unsigned long temp;
int i; unsigned i;
int j_offset; unsigned day, dw, dm;
int day, dw, dm;
memset(days, SPACE, MAXDAYS * sizeof(int)); memset(days, SPACE, MAXDAYS * sizeof(int));
if ((month == 9) && (year == 1752)) { if ((month == 9) && (year == 1752)) {
/* Assumes the Gregorian reformation eliminates
* 3 Sep. 1752 through 13 Sep. 1752.
*/
unsigned j_offset = julian * 244;
size_t oday = 0; size_t oday = 0;
j_offset = julian * 244;
do { do {
days[oday+2] = sep1752[oday] + j_offset; days[oday+2] = sep1752[oday] + j_offset;
} while (++oday < sizeof(sep1752)); } while (++oday < sizeof(sep1752));
@ -214,7 +212,7 @@ static void day_array(int month, int year, int *days)
} }
/* day_in_year /* day_in_year
* return the 1 based day number within the year * return the 1 based day number within the year
*/ */
day = 1; day = 1;
if ((month > 2) && leap_year(year)) { if ((month > 2) && leap_year(year)) {
@ -227,17 +225,15 @@ static void day_array(int month, int year, int *days)
} }
/* day_in_week /* day_in_week
* return the 0 based day number for any date from 1 Jan. 1 to * return the 0 based day number for any date from 1 Jan. 1 to
* 31 Dec. 9999. Assumes the Gregorian reformation eliminates * 31 Dec. 9999. Assumes the Gregorian reformation eliminates
* 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all * 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all
* missing days. * missing days.
*/ */
dw = THURSDAY; temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1) + day;
temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
+ day;
if (temp < FIRST_MISSING_DAY) { if (temp < FIRST_MISSING_DAY) {
dw = ((temp - 1 + SATURDAY) % 7); dw = ((temp - 1 + SATURDAY) % 7);
} else if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS)) { } else {
dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7); dw = (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
} }
@ -250,10 +246,9 @@ static void day_array(int month, int year, int *days)
++dm; ++dm;
} }
while (dm) { do {
days[dw++] = day++; days[dw++] = day++;
--dm; } while (--dm);
}
} }
static void trim_trailing_spaces_and_print(char *s) static void trim_trailing_spaces_and_print(char *s)
@ -263,7 +258,7 @@ static void trim_trailing_spaces_and_print(char *s)
while (*p) { while (*p) {
++p; ++p;
} }
while (p > s) { while (p != s) {
--p; --p;
if (!(isspace)(*p)) { /* We want the function... not the inline. */ if (!(isspace)(*p)) { /* We want the function... not the inline. */
p[1] = '\0'; p[1] = '\0';
@ -274,9 +269,9 @@ static void trim_trailing_spaces_and_print(char *s)
puts(s); puts(s);
} }
static void center(char *str, int len, int separate) static void center(char *str, unsigned len, unsigned separate)
{ {
int n = strlen(str); unsigned n = strlen(str);
len -= n; len -= n;
printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, ""); printf("%*s%*s", (len/2) + n, str, (len/2) + (len % 2) + separate, "");
} }
@ -287,15 +282,16 @@ static void blank_string(char *buf, size_t buflen)
buf[buflen-1] = '\0'; buf[buflen-1] = '\0';
} }
static char *build_row(char *p, int *dp) static char *build_row(char *p, unsigned *dp)
{ {
int col, val, day; unsigned col, val, day;
memset(p, ' ', (julian + DAY_LEN) * 7); memset(p, ' ', (julian + DAY_LEN) * 7);
col = 0; col = 0;
do { do {
if ((day = *dp++) != SPACE) { day = *dp++;
if (day != SPACE) {
if (julian) { if (julian) {
++p; ++p;
if (day >= 100) { if (day >= 100) {
@ -304,7 +300,8 @@ static char *build_row(char *p, int *dp)
day %= 100; day %= 100;
} }
} }
if ((val = day / 10) > 0) { val = day / 10;
if (val > 0) {
*p = val + '0'; *p = val + '0';
} }
*++p = day % 10 + '0'; *++p = day % 10 + '0';
@ -348,5 +345,3 @@ static char *build_row(char *p, int *dp)
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE. * SUCH DAMAGE.
*/ */