函数名: asctime% K# o x' i4 t
功 能: 转换日期和时间为ASCII码; D1 ~. T; w5 o" a: L8 {" N
用 法: char *asctime(const struct tm *tblock);
2 s5 C! Z# G6 R) I 程序例:* L# b) J5 Y' d: r: n' w1 Q# T6 \
#include
G' z% u+ { p #include- v# ` m6 {6 y7 \0 d" V; Z3 `0 E
#include: r D v! {% m8 R
int main(void)
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struct tm t;
8 o5 V- Z! W. T' m char str[80];" Q; T+ S5 Q2 G1 T2 K% f# }$ I
/* sample loading of tm structure */
+ l" J- I6 n+ d* K a! l) s7 a0 c t.tm_sec = 1; /* Seconds */1 v7 n/ C# m, C
t.tm_min = 30; /* Minutes */1 L$ I/ g. i7 o5 V8 b
t.tm_hour = 9; /* Hour */
- v) v& A& _, b t.tm_mday = 22; /* Day of the Month */
+ j4 h" n6 N e) ?6 G& U$ a t.tm_mon = 11; /* Month */8 B Q1 p( E6 U- x- O; _+ }$ V
t.tm_year = 56; /* Year - does not include century */; S0 R4 V2 i! r5 F1 V* S
t.tm_wday = 4; /* Day of the week */; _; L" H' [! h6 |$ I7 i
t.tm_yday = 0; /* Does not show in asctime */- o2 v& A3 h. P3 L* {& k
t.tm_isdst = 0; /* Is Daylight SavTime; does not show in asctime */
5 B' g6 m! ?$ ?7 o$ q /* converts structure to null terminated: _( g: @; @; v: ]3 ?0 f
string */
' a$ G8 k) }& k3 ?8 ^/ R strcpy(str, asctime(&t));/ a) ]" I$ i8 O" C6 E
printf("%s\n", str);" j1 |( G& i: Q/ L4 `) \; w8 G5 n: ]
return 0;( f3 `% W" D5 |1 L9 a& H3 ?
}
" N1 c4 @% Q3 x0 s' s6 I9 J6 \ 函数名: asin
' b/ _4 t; {2 H% A: I2 J4 w& T 功 能: 反正弦函数
* z! M, V9 K% T$ H- [9 ?2 j2 ? 用 法: double asin(double x);) Y, E+ ^4 ^, e ~$ |1 H0 e
程序例:
6 ` L1 J; _& A; s2 d, t #include: l4 @6 G' R ]3 h1 g! E- J9 u4 U
#include8 W6 ~3 v1 W8 L. o6 ^; J8 K
int main(void)
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) }# k o, Q+ X- c. m double result;
1 ~+ O: f# A& J4 Z. N" }* ?% D double x = 0.5;' |6 E g% l7 [- E8 H) R- J
result = asin(x);8 U, m6 x0 S$ l$ Y9 m/ ]% I
printf("The arc sin of %lf is %lf\n", x, result);
; K9 m- S" g% E9 p! ^ return(0);! I2 p1 x' G% I4 d o" b; O9 o
}
; h: Q. z% n/ D8 N8 H 函数名: assert' R' B6 W3 ?" P2 l4 P- @% X$ o
功 能: 测试一个条件并可能使程序终止
4 [0 }- M8 @$ q 用 法: void assert(int test);5 t" @+ v3 ?, L
程序例:" z8 ` o' l# d4 p: E1 W
#include& e4 L( `" e- o- c* D @7 y
#include
! U! K9 x1 u3 z1 `# S3 J- } #include& b4 e( l7 H" \ X& Y4 _, |' J
struct ITEM {) j+ ~8 W$ _* O. x! Q1 b
int key;
8 X- r% f* V6 d6 O int value;
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/* add item to list, make sure list is not null */- R9 s, Z* @! G2 T( c: o
void additem(struct ITEM *itemptr) {! ?9 [ V& @% M `+ l' }
assert(itemptr != NULL);
, ~2 t7 H" w3 g /* add item to list */; f: W' u2 X7 }) p x
}
9 x8 {! R6 }; j int main(void)
; w' v8 v. U/ C/ b {
- ?( P6 Z" _& j# r, }$ A additem(NULL);. C9 |' c+ Y3 A0 `& ]
return 0;7 s/ X# N% b/ F# Q
}
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