数学建模社区-数学中国

标题: 函数大全(c开头) [打印本页]

作者: 韩冰 时间: 2004-10-4 03:02
标题: 函数大全(c开头)

函数大全(c开头) 3 J+ g6 D+ e/ x3 v% l8 H& ]! `( n

函数名: cabs 3 D2 H/ l3 |% D' g: d/ X功能: 计算复数的绝对值 ( }9 f% f' i. L+ V; F3 Z) y) w7 | 用法: double cabs(struct complex z); / e2 ]+ d: T; b2 p0 e 程序例:

#include ' @3 M2 \- ]) h8 w1 f; G& Q#include

int main(void) 5 R7 b7 f4 F: f { ; n8 D* f, N9 B$ U1 h# R5 Y8 a6 L struct complex z; ! \3 Y! s* Q8 \- D0 \+ d M' X double val;

z.x = 2.0; / i. [% K9 a3 Z0 c$ n! Y! i# V: }z.y = 1.0; 9 X. Y7 ^, M( i: X val = cabs(z);

printf("The absolute value of %.2lfi %.2lfj is %.2lf", z.x, z.y, val); 4 a' j# f/ t1 c2 c% U4 L return 0; & a7 t- f+ [# e* {7 ?( ] } & @# I) I3 I n4 n 9 E4 _8 J$ _- U3 w( R$ f! [( B n/ H( Y7 |! s( j' E% C

函数名: calloc 4 q/ y, F. N' p! Q- X6 H8 N功能: 分配主存储器 # l3 w3 G5 ^( n% O% V2 M$ m用法: void *calloc(size_t nelem, size_t elsize); - E) t6 N D$ K2 j! R' V* o程序例:

#include / m' ]0 U; w1 ~& I/ o$ C& v3 R" N #include

int main(void) 9 i6 b0 [( v R1 I{ / i; U( ?" E7 y' | char *str = NULL;

/* allocate memory for string */ $ f0 q3 P6 U' {" T2 c3 m3 c str = calloc(10, sizeof(char));

/* copy "Hello" into string */ 4 Z: f/ a8 L1 I" t' R- ^+ o8 ` strcpy(str, "Hello");

/* display string */ 4 ~* @- Z) x; m: U* G# m/ xprintf("String is %s\n", str);

/* free memory */ + m; ~+ m8 {: n' m$ x. M, c& ]) t free(str);

return 0; $ p' d) a8 p. R3 ?, B7 J# ~7 ^! { } - j* e# }% s" ~/ t" c( w- H 6 y& q: t, b( V$ n* j8 Y8 D& P+ b4 Z; k

函数名: ceil * l8 C2 D* m. l功能: 向上舍入 , I# ]5 i8 O& X用法: double ceil(double x); 6 a0 s1 N/ p+ M1 c% p6 Y" m 程序例:

#include 7 T, U. u- s X5 R* s) r% m+ u #include

int main(void) 8 V2 T8 Z/ i" m/ ? { * O0 F# _1 s: f5 ]0 {" B& U double number = 123.54; 7 K* K% u0 ?1 [- C+ g6 j* Y0 T' Kdouble down, up;

down = floor(number); + h8 `- ]0 A2 Q% X2 {* V. kup = ceil(number);

printf("original number %5.2lf\n", number); * X# C5 [& b, p/ k printf("number rounded down %5.2lf\n", down); ' P3 K- k2 |7 p9 ?. q printf("number rounded up %5.2lf\n", up);

return 0; ) g2 d, m& Y* n* [4 k# d} ( C: a$ x, X, B. A- N# B 3 N9 F& O5 P/ j* b. X8 W" f2 S; y- j7 \" h

函数名: cgets , ~% c r) o8 ], U- ^ 功能: 从控制台读字符串 * s+ R, h) q L/ i& g, q/ o( N用法: char *cgets(char *str); 8 l J/ b8 b. l 程序例:

#include + T6 u& j7 y# m8 O9 G9 }) b#include

int main(void) M5 X9 \( N; C- H2 N0 S% i7 F{ ' z/ j& ?+ ?3 S i& z- n char buffer[83]; 6 X8 _% d5 D `5 p# h p2 p0 ]char *p;

/* There's space for 80 characters plus the NULL terminator */ ! Y+ X5 ~8 ^1 Y% ]! C2 h buffer[0] = 81;

printf("Input some chars:"); * F( D4 A# j3 U+ qp = cgets(buffer); * V6 o: q& F! Q1 rprintf("\ncgets read %d characters: \"%s\"\n", buffer[1], p); $ @' l7 I8 f0 K- f( l! d: _ printf("The returned pointer is %p, buffer[0] is at %p\n", p, &buffer);

/* Leave room for 5 characters plus the NULL terminator */ 4 `" v/ i* u, a# nbuffer[0] = 6;

printf("Input some chars:"); 8 _: e; v% B, f9 T: ep = cgets(buffer); / P/ W1 O! D! T( j" b K# }printf("\ncgets read %d characters: \"%s\"\n", buffer[1], p); ! T( F4 k8 s/ Y+ Dprintf("The returned pointer is %p, buffer[0] is at %p\n", p, &buffer); + y# a0 n$ c9 b5 J5 Z0 @8 k( ^3 R. zreturn 0; ( t V; z! V; _; C {: I, x} ' O5 X0 ]1 f, k# ]$ t9 H& W& r) n$ l! M, k + N' U$ J' X& Y

函数名: chdir 3 b7 X9 K& z- F$ l5 X功能: 改变工作目录 + a' w0 z7 `# l5 _ 用法: int chdir(const char *path); , m. P" [2 c7 a 程序例:

#include ' I0 S+ w/ ]; F1 i* P. Z0 p/ Y #include 6 F3 k3 l0 f# U8 ^6 U7 S0 Z#include

char old_dir[MAXDIR]; * w" S( e p. T5 L2 k% d9 {1 vchar new_dir[MAXDIR];

int main(void) 0 x" S. S( v' X5 H( W) \ { " e- Y. t! H3 H3 ^: g* ]; H! Sif (getcurdir(0, old_dir)) & Z7 [( b3 O0 G% B { H5 d$ d F; V( N; y9 Operror("getcurdir()"); $ i) U* H {7 `' j6 n6 o exit(1); & D& k' z- o: ^ w- `1 x; g } 6 q& |% [# o$ {. t, k9 fprintf("Current directory is: \\%s\n", old_dir);

if (chdir("\\")) $ j! q9 d/ \5 F4 M `! f6 M' v' ` { + C# j, t9 w6 ~ perror("chdir()"); , O, z# b8 }0 ?/ q+ @ exit(1); * N0 ]: c* C* x: Q5 ?( Q( z3 K }

if (getcurdir(0, new_dir)) % P* w+ e8 \: x( ` { 4 q1 {2 Y% w7 L1 z4 u- F* r% A perror("getcurdir()"); 3 p( R9 |( U' g6 \- H/ g8 k/ ~exit(1); % T) K1 U& V$ F- e- y& X% R; N } ; }3 L' B. s! j) S" x+ a5 [" X6 Mprintf("Current directory is now: \\%s\n", new_dir);

printf("\nChanging back to orignal directory: \\%s\n", old_dir); ' C) \8 k$ A& ^5 R. O7 ] if (chdir(old_dir)) * x# x6 e3 b. g{ 0 l( F6 f, w6 W0 Pperror("chdir()"); - ^0 _/ d7 s& I exit(1); ( X" h) K4 |7 @ x- f/ x* L ^}

return 0; 6 m. B4 y8 M" \7 @7 F9 L) n3 l* u} . Y1 g1 ?9 U' G& ]- ?! O ; d4 o9 y# s2 a) H$ X

函数名: _chmod, chmod 7 b6 j! i2 V" x# |8 h功能: 改变文件的访问方式 + ^! \2 k i' A; ?0 M" d4 Y 用法: int chmod(const char *filename, int permiss); # e- j& ]9 ^! [2 G( s& Y程序例:

#include % W# d, L5 t- U9 g, g7 a #include " O- s1 E* X7 u6 U1 j#include

void make_read_only(char *filename);

int main(void) ( t r" r; u8 j% {. F/ k{ J% p# B* |9 B% L2 o" ~6 O make_read_only("NOTEXIST.FIL"); . Y7 o+ B6 U& b3 j5 f# }, z% w/ j" Q% P make_read_only("MYFILE.FIL"); 3 ~$ N1 E7 J% _9 ?$ I3 u- W* Y, hreturn 0; ; n+ `2 ?" m1 E }

void make_read_only(char *filename) ; j8 }/ e r/ N0 A8 I' W: e { & ?4 \) {$ p9 `' Z I$ Q0 r5 Sint stat;

stat = chmod(filename, S_IREAD); % j. @ [5 s' \% T$ A' b0 K7 k f if (stat) 1 z5 p7 h+ W: H% e; P/ e* p printf("Couldn't make %s read-only\n", filename); ) G9 L& B6 ~# s4 H. Helse - F s0 @9 y$ c9 L: j/ E1 Mprintf("Made %s read-only\n", filename); # }0 r8 }0 m1 Z; V5 X2 ]# n} # @2 N0 X: C2 |( z* C9 Q& g8 [ $ L. x7 O2 j9 G5 H$ N H% Z 1 A7 {0 y- r/ z% M. f8 r; f* {( B

函数名: chsize * Z, G. _ B1 H& _# E 功能: 改变文件大小 5 D& P$ {& E8 @6 T% @ 用法: int chsize(int handle, long size); 4 U& }9 _4 [! ^2 x' Z程序例:

#include " L6 c/ y5 I/ {5 w* X; }#include ! G1 J2 D p5 L7 k+ W#include

int main(void) `. r- |# I; g1 G2 e% P" {{ - @$ s$ m/ V8 C/ ^: R2 W+ P% T0 xint handle; ! y' n6 n- ~, G; v char buf[11] = "0123456789";

/* create text file containing 10 bytes */ - w; D% a6 K: O3 `; B; Jhandle = open("DUMMY.FIL", O_CREAT); 9 ^) T% L9 R1 P2 f; w: j8 ?( K write(handle, buf, strlen(buf));

/* truncate the file to 5 bytes in size */ 2 P3 B/ Q# O9 L( Z# \7 pchsize(handle, 5);

/* close the file */ 8 [1 B" C- H! f" E; L# x* Pclose(handle); $ ~. V4 @2 J$ F- x- creturn 0; : K" z8 q/ g X0 @3 v9 A } $ s8 z% h1 u' p* i$ r% V8 V3 { ( A, t* K1 J& x" `! }! g3 l

函数名: circle 1 c4 W' M H# y( u功能: 在给定半径以(x, y)为圆心画圆 & }3 ~8 d: _+ s 用法: void far circle(int x, int y, int radius); 1 v2 W* `. b( d1 N, C+ Q$ s2 J 程序例:

#include 2 H9 ]' t2 m! X, X& P$ b( r#include ( f4 @ i' N5 q' p* G0 V6 d; v#include ; N( W1 h* Y% C6 C( W5 [: i' y: _#include

int main(void) 1 |' Y+ i: w1 S{ ' u8 a1 T1 H5 h: \ /* request auto detection */ , F8 k" m: x1 Nint gdriver = DETECT, gmode, errorcode; ' F! c9 b: h* U! Q int midx, midy; / q5 h$ K2 q! V, Dint radius = 100;

/* initialize graphics and local variables */ ! c2 H, b g& P5 V& _7 y/ y0 S initgraph(&gdriver, &gmode, "");

/* read result of initialization */ 3 x/ U$ G1 I% ~# ~$ Cerrorcode = graphresult(); , Q4 x$ A; H- K' Y% X: a if (errorcode != grOk) /* an error occurred */ 9 P6 i O' z: F \2 B1 f5 `{ * |0 } d( X* f4 } printf("Graphics error: %s\n", grapherrormsg(errorcode)); " T8 \# ~6 Y5 ~0 Q4 p printf("Press any key to halt:"); # _$ b5 t: T0 E, q* q% J getch(); 3 ^: d$ z7 k& _exit(1); /* terminate with an error code */ ' g: V4 {# n: a7 _ }

midx = getmaxx() / 2; 5 Z, Z6 p9 o8 B1 m# W L midy = getmaxy() / 2; 4 \( U$ |+ ?! X setcolor(getmaxcolor());

/* draw the circle */ ( s' I" Q3 V2 x% p1 f8 Mcircle(midx, midy, radius);

/* clean up */ ; x" K# J3 a/ ~6 A9 ~' o5 U getch(); 4 K/ G: |; c! l$ {& m5 J0 `closegraph(); 6 [4 o( q4 d$ s% j7 ]/ Hreturn 0; 5 D& n; V) Y; N; g4 q e } " k& @9 X% Q! z% }; y l. ^/ L L7 n _0 t7 V2 i4 } ; m$ p4 ?% @! w( X6 ?

函数名: cleardevice , {# s; u8 y+ j 功能: 清除图形屏幕 f; ^$ b8 ^0 I0 h+ w* r用法: void far cleardevice(void); ) h$ F* c# v. ^' G程序例:

#include $ Q. @% p4 e4 f( _5 K) h #include & g8 y* h, n, O: X. k# W #include * o6 }) ^0 k$ |6 M% O#include

int main(void) ) V* z; h! w' k; |( [4 j { ! g& Y# P: g& L1 w( H/* request auto detection */ $ R# a$ l2 z) @9 m. d. \int gdriver = DETECT, gmode, errorcode; 7 X( S4 ?; L/ w, m! C2 F int midx, midy;

/* initialize graphics and local variables */ 2 Q1 e/ G$ \% C: T6 E+ Y/ s7 j initgraph(&gdriver, &gmode, "");

/* read result of initialization */ 9 y+ O9 M9 i0 J errorcode = graphresult(); ) n1 ?0 G1 x/ B- ^if (errorcode != grOk) /* an error occurred */ : ?+ Z& s5 l- n. v{ ~2 g$ \7 e/ ~5 z! ] printf("Graphics error: %s\n", grapherrormsg(errorcode)); - m) d1 a% i# n. ^4 L printf("Press any key to halt:"); 1 ~# p% m) E; Egetch(); ' p8 e9 u$ W9 m2 q3 R% v: ? exit(1); /* terminate with an error code */ ( Q0 K6 X W G/ `0 l: R9 b }

midx = getmaxx() / 2; P/ y( i5 ?* V) g$ R# q3 y midy = getmaxy() / 2; setcolor(getmaxcolor());

/* for centering screen messages */ 4 @( B" e2 r w3 j e X2 C5 {settextjustify(CENTER_TEXT, CENTER_TEXT);

/* output a message to the screen */ , i: c8 _0 M# x. _& ` outtextxy(midx, midy, "press any key to clear the screen:");

/* wait for a key */ 2 e$ A% ~9 G# b. [" A e getch();

/* clear the screen */ 2 a, D) w3 B: w6 X" | cleardevice();

/* output another message */ 2 F9 Z* w+ z9 H/ ]outtextxy(midx, midy, "press any key to quit:");

/* clean up */ : z" U4 F, `% V' ^% t9 u. b N getch(); $ a' x' C9 _# _. R closegraph(); 8 h! i9 {' ]" x1 e8 j T, n. f: m' |return 0; 4 v9 E) b) _7 Q$ P6 B} 8 ]9 B0 m2 A: E/ ?0 F " f W! {+ l* y0 X1 j' l1 T 3 j+ R, G" B M( G- z

函数名: clearerr ( i! `" g; u3 I% v& T3 f 功能: 复位错误标志 ! j' e. }* T$ |' U; F, K( } 用法:void clearerr(FILE *stream); " p3 N) _6 k( L/ r9 A* p- i# D3 S程序例:

#include

int main(void) " N0 ]; C O! |! W5 Y1 N{ 0 v( i+ ]- \6 p" b, x3 AFILE *fp; . p n+ \! m7 I( L2 E+ _char ch;

/* open a file for writing */ & Y# C- j; ^9 D. N fp = fopen("DUMMY.FIL", "w");

/* force an error condition by attempting to read */ H, {( Z; z7 [. [) u ch = fgetc(fp); 7 ]! K9 B6 e) o; I1 Oprintf("%c\n",ch);

if (ferror(fp)) 5 w5 ~3 ?4 L: K7 {; h H{ $ h1 J# C7 e+ e t7 ]4 T3 Y /* display an error message */ & i' [% ]. S! e0 |. wprintf("Error reading from DUMMY.FIL\n");

/* reset the error and EOF indicators */ 2 s* d0 e* F. K8 w, Mclearerr(fp); ! U+ A8 |6 @$ G1 z* v2 }}

fclose(fp); ) w* y. \9 Z ^1 a2 E) K8 u return 0; 3 V. G. r# L; f } % ?. i$ c$ ]! Y3 B! S& c' A. ^% S0 _' m ' E7 M9 j2 ^$ t" p6 T* w" M# X

函数名: clearviewport : W, F: b$ ^: L& n) Z0 R1 | 功能: 清除图形视区 1 ~! P" D5 |/ U用法: void far clearviewport(void); + k/ d( i9 e8 j0 U( r( W r! U程序例:

#include , V; J: ?7 d: S! ^6 } #include " I. B7 x% {& g#include ; ]: C6 ]2 V6 E1 V% ]9 F4 N: j #include

#define CLIP_ON 1 /* activates clipping in viewport */

int main(void) & R5 B% u( u* t8 T4 [9 e1 t{ ! |1 c( F$ B6 ?8 O/* request auto detection */ 4 Z" P, g' u$ p1 B6 J5 Gint gdriver = DETECT, gmode, errorcode; 2 N" E+ x" Q: D! o int ht;

/* initialize graphics and local variables */ # ?1 u/ D$ o4 dinitgraph(&gdriver, &gmode, "");

/* read result of initialization */ " u, z3 K, @( F( q" | errorcode = graphresult(); 2 S+ v6 f% {- ^& @5 Z) b if (errorcode != grOk) /* an error occurred */ $ n& A) K: r% \% U+ p4 B7 c3 O{ . C+ c; ]* v! X' X1 a5 | printf("Graphics error: %s\n", grapherrormsg(errorcode)); 3 w. p: @" N* t9 a/ p9 `# tprintf("Press any key to halt:"); 6 s. f s( C) g z5 o$ G getch(); % f5 i8 U* k' }8 `% H4 Rexit(1); /* terminate with an error code */ 6 ~( v( F8 ~2 d3 c}

setcolor(getmaxcolor()); : S" j$ p* J* I r5 S3 g1 yht = textheight("W");

/* message in default full-screen viewport */ 0 m. L9 z5 ]' g3 I0 D outtextxy(0, 0, "* <-- (0, 0) in default viewport");

/* create a smaller viewport */ ' d3 k6 g! g$ q; | W setviewport(50, 50, getmaxx()-50, getmaxy()-50, CLIP_ON);

/* display some messages */ $ M) i4 y( `4 X7 t; L4 Youttextxy(0, 0, "* <-- (0, 0) in smaller viewport"); 1 Y% U, J" Q/ Qouttextxy(0, 2*ht, "Press any key to clear viewport:");

/* wait for a key */ % s- a- o, e3 g3 Q5 B1 _' mgetch();

/* clear the viewport */ 9 M% @; w; h2 r {. a$ @ R clearviewport();

/* output another message */ " |# v) e) q+ R1 k. k2 E1 uouttextxy(0, 0, "Press any key to quit:");

/* clean up */ ) ^! M0 P* E8 Q; D$ r# P* @getch(); % z' A' O6 T9 N* A# T+ Y( m% v closegraph(); 5 a$ z0 w0 p1 W; G' f) Z return 0; 9 N/ u4 k) w5 ? } # Q4 F/ B2 i" j" N' h- q% S2 e / O$ x. G3 I c/ l" P) n8 i( m# ^- N" Y* z) l! k) V, x; q

函数名: _close, close 3 y) l5 t9 {4 _$ k* A: D功能: 关闭文件句柄 : z, o2 e1 L6 t5 Z# ^! ?/ z 用法: int close(int handle); - H; E' H' w& Z程序例:

#include - ]6 v" H7 F! p# V6 t& g- H#include / ^ H; A& C* O+ w9 G#include - g8 n- T$ F( q2 R. M# ^- Y+ m0 U#include

main() + k# N/ `, F7 S4 u( f! \{ : F2 A0 B3 y! m3 B/ W# s8 c' f; Vint handle; ' i/ [! ?, V, k1 } char buf[11] = "0123456789";

/* create a file containing 10 bytes */ 4 n" e, r/ D0 V9 Z5 @) Nhandle = open("NEW.FIL", O_CREAT); . G, ^: k9 v+ w if (handle > -1) ! A7 j; v. L4 g/ {* X { 9 J! l7 ^/ e" S/ N! ~& Zwrite(handle, buf, strlen(buf));

/* close the file */ 5 {$ S# n- D3 hclose(handle); 9 O( T, I1 L( E } + i( |$ e( z3 n else / }& I; s; V1 D% r% ~9 e; z { - c: V5 t! z' I5 p printf("Error opening file\n"); + ~6 A& W$ n5 P! t* Z} + n8 y7 P3 g/ A7 |) `0 E% l return 0; , X8 k3 ^; W5 r( w ]/ j/ z! F} ! K) [6 [/ ^/ a) X/ J3 }( P) [! _6 p5 {4 h( D& S 5 T& D$ S. u, B& p% _* c M& ]7 U

函数名: clock 9 G; x+ k1 D0 |! _& l4 ~5 S功能: 确定处理器时间 : ~3 S% `* a- W( F: Z6 B 用法: clock_t clock(void); 0 X( i( G" ^5 y, ~2 B8 P程序例:

#include $ {: K% F7 T2 P9 U( j! W% I: ` #include 9 |) `; u* I9 q, x1 A$ @: C d#include

int main(void) * y3 r, |% D- f { 2 l. m3 F4 }. qclock_t start, end; ( g* t) X* `: ~ start = clock();

delay(2000);

end = clock(); $ \9 B" c. |( B( i; n: p- m- ~0 Z printf("The time was: %f\n", (end - start) / CLK_TCK);

return 0; + A" o( m t! S} " K7 v i- j7 ?$ S' M" d 6 V8 m, a& D. O: a 4 e6 { U1 G9 x, @7 j6 h

函数名: closegraph 6 n5 P& \ w! E: t9 _功能: 关闭图形系统 ) H. L3 K+ ~" U7 [, J- _! w& y用法: void far closegraph(void); 7 o! d. p5 m# ~+ S: S7 r+ x 程序例:

#include + h% f! ?7 u/ F7 H #include 7 M. V0 }; _" E$ D! A7 f #include % X' p$ ^6 m" k9 _) G0 K0 d M# a #include

int main(void) 9 O' Z. M# i# \5 l3 g% p% Z { : |2 v$ S. ~7 x4 M1 V /* request auto detection */ ( A# A! V* n8 }8 v7 @; z. j0 O7 {int gdriver = DETECT, gmode, errorcode; ( m* p8 s; P1 S6 z/ M2 x$ j K int x, y;

/* initialize graphics mode */ & q' c9 ^9 Q; O& A+ J% w2 |initgraph(&gdriver, &gmode, "");

/* read result of initialization */ 8 g2 o8 k( C6 m* D9 ierrorcode = graphresult();

if (errorcode != grOk) /* an error $ W8 B! _) _4 R$ A# D& y occurred */ 7 ^, D2 B& n# B$ L0 q{ - H+ s" v# J& W6 X! ^4 @printf("Graphics error: %s\n", grapherrormsg(errorcode)); $ D/ c/ B! \6 g5 ^* h6 `0 N5 c printf("Press any key to halt:"); - {% u. e( W8 v8 F9 _" Ngetch(); ) ^3 A( \- H: C$ v2 v3 }' n exit(1); /* terminate with an error code */ 1 H2 [% d6 z- l8 t) k# n, s}

x = getmaxx() / 2; ' z) E( u$ c ^. by = getmaxy() / 2;

/* output a message */ 3 O( ?5 \3 z: p) \settextjustify(CENTER_TEXT, CENTER_TEXT); $ a6 J7 ?7 D9 L" M5 \5 m& I5 f outtextxy(x, y, "Press a key to close the graphics system:");

/* wait for a key */ ! J7 A8 K' t; a, N1 M& y' F3 O: ^ getch();

/* closes down the graphics system */ ' V$ G$ G4 l ]1 F6 ]( gclosegraph();

printf("We're now back in text mode.\n"); 4 ~ Z# D" R9 U7 K0 M printf("Press any key to halt:"); % K; O2 P# @ ~4 Z# [. _8 Z getch(); - W7 `5 \% e& t6 m2 e" K0 n* @return 0; 6 v, ~8 \8 |% u} : O7 f2 c q( F7 k9 q+ K# G i3 S/ c/ |% n9 N4 f W$ ? J7 V6 u ' D+ y9 C; L& j6 V5 r# z

函数名: clreol $ [1 U/ c4 U+ X 功能: 在文本窗口中清除字符到行末 3 B1 H* c; k1 ?& M4 r. W' |用法: void clreol(void); 4 A6 C [% V4 S( D: X O! r; V程序例:

#include

int main(void)

{ - |$ u/ o) ~7 ~/ [$ o$ V) Gclrscr(); 4 s3 w0 r" O/ v cprintf("The function CLREOL clears all characters from the\r\n"); 5 E) n, T4 T7 g3 c, K$ hcprintf("cursor position to the end of the line within the\r\n"); ; r2 d; T+ u, _2 K M cprintf("current text window, without moving the cursor.\r\n"); 4 c: z: R5 i9 I6 Y cprintf("Press any key to continue . . ."); , {5 H% b7 u# U2 b& `7 X gotoxy(14, 4); " F2 m ^4 o1 t# ?" zgetch();

clreol(); # w$ C6 @. y/ A9 M0 l( h- J7 o lgetch();

return 0; ! ?/ A8 h7 a* U } ( S; _ _8 j5 I$ r. r2 \ : K. p- O y0 q& f- d% W, K$ D& _4 o! s. T1 M) r: q5 H2 M

函数名: clrscr % f6 W% Q! z4 [; G* T/ k' B4 D# ? 功能: 清除文本模式窗口 ' [$ C3 v& W( K; G+ m$ @$ J0 U! r 用法: void clrscr(void); * d* B L1 y1 S) r& M程序例:

#include

int main(void) 5 m. i9 H6 U5 S{ ) M9 C! x, K8 w( l% W7 i3 tint i;

clrscr(); ( k/ N5 D% o: j! Y$ |! t- w2 nfor (i = 0; i < 20; i++) - _6 W- [$ U' Y" R8 P, F cprintf("%d\r\n", i); * r) j: h( w0 Ccprintf("\r\nPress any key to clear screen"); ! C: y. b1 \& F( F/ B- U$ I; Pgetch();

clrscr(); ! {) A* y) Z3 m9 n) ^1 J4 k& L cprintf("The screen has been cleared!"); - J6 \ c" ^$ G# K& R2 Bgetch();

return 0; # s8 `5 i' `% j3 k } 3 G) \8 H/ i# T4 _1 ~* _ 0 W0 U( ^& [3 H4 Y2 ~# p( c ) N( y* ^6 F( _! Z

函数名: coreleft : u8 ?# F8 E% i5 g5 t 功能: 返回未使用内存的大小 . m1 u s; s$ W& L" y/ A7 }; |. q1 p' K 用法: unsigned coreleft(void); * e* Q0 h2 W- S程序例:

#include / P' }: D' f1 } @1 Z #include

int main(void) 2 o2 p9 Z2 @ g" r& `" D{ 4 `( \& l- ~0 {/ V7 k) H printf("The difference between the highest allocated block and\n"); 5 v8 m. l; }4 u/ z" B X4 o$ Q1 J printf("the top of the heap is: %lu bytes\n", (unsigned long) coreleft());

return 0; % H. o2 A# c/ ?5 A3 n} 0 t8 T- t; d$ h1 e

函数名: cos , c! g2 K, t% D- e1 m6 z功能: 余弦函数 ) I! d T9 u5 V: d/ s$ G- w用法: double cos(double x); . a9 w% ]: u9 ]0 o# g 程序例:

#include % A. y& H4 j$ u2 ?! N1 C" O#include

int main(void) ! o/ i% _. y; h { ! m) l$ H* f' e$ u5 U+ hdouble result; % |- e/ d- A7 g Z$ m: n9 X4 N8 Q double x = 0.5;

result = cos(x); $ H% j+ c7 ]$ ^ T, o) uprintf("The cosine of %lf is %lf\n", x, result); , A4 K4 w- O; _4 `2 _; s return 0; ( y2 S6 a; Y \& P6 ~- \7 M& z9 o} " F8 G9 G5 z- {4 [0 t! } * x* K+ B% j) \" B+ L. `1 G ! |1 Q0 `/ G- b! C7 X2 j

函数名: cosh ' h% o$ K/ S! B* T0 p0 X0 m 功能: 双曲余弦函数 - T: V, z8 U* T- R3 u+ E0 q 用法: dluble cosh(double x); ' Q. a- h- v$ d& b$ Y4 T( X程序例:

#include 6 Y% U3 c, \) _' o, b #include

int main(void) : |: N$ @/ j# z0 U1 H' Z { + F7 G6 M C N8 a$ ]% s! f double result; 3 o; A! ^; d/ `5 V8 p& pdouble x = 0.5;

result = cosh(x); / U5 D/ p3 H6 h) \: j, a" Zprintf("The hyperboic cosine of %lf is %lf\n", x, result); % G& e9 g, [6 W2 a, x return 0; / w; j6 d& ]% s5 j6 b} & g! G! k0 z# C& ]4 Z + D7 s" [% K$ b0 E6 l$ p; X0 |( x0 p% o! D$ k. }3 j

函数名: country + L( K' H! z% w$ q- M 功能: 返回与国家有关的信息 V& v: f9 Z4 |. P5 I用法: struct COUNTRY *country(int countrycode, struct country *country); ( i% W7 }% b0 `3 _( s; F程序例:

#include ! [/ i% f' _8 l- X/ a ` #include

#define USA 0

int main(void) & {% \1 v- |# u4 v2 r$ k { ) T- _. Q6 C& }% r# \2 `) K% e struct COUNTRY country_info;

country(USA, &country_info); ( O. b6 b% K/ k& F+ K3 Q printf("The currency symbol for the USA is: %s\n", , A5 I: F( @: @& A( n' Q4 x5 _ country_info.co_curr); 3 ?8 b, ^! a, T, z% Z6 } return 0; 8 ]. B W T5 ^: e& ^, t8 n) l4 e } . d! C. N. T/ |8 l. h* R 6 g4 t0 u$ s! I5 t. j! G# L- H 3 O8 w4 v7 g" O5 @/ h

函数名: cprintf + J/ q! U9 q q% U% s8 S( W0 [ 功能: 送格式化输出至屏幕 " J% y# G: J1 V* X- G# ~( d" \用法: int cprintf(const char *format[, argument, ...]); ; I: L$ s& V$ f: x# V程序例:

#include

int main(void) ( X0 L2 d9 W# x7 o) |- r { ) m+ Z8 E: p @0 o0 d: c /* clear the screen */ 3 g) [9 a) h& c2 h, n/ S clrscr();

/* create a text window */ / a7 w2 p2 v y window(10, 10, 80, 25);

/* output some text in the window */ 3 M: d, U3 W f' u cprintf("Hello world\r\n");

/* wait for a key */ 3 N$ K5 ?+ S; S) h getch(); / \ H' Q$ o, W8 areturn 0; 9 P' b/ h' U- H& q9 S) i, O x} / u* b4 _% G8 f- \7 l8 G9 ?6 c7 z% T: I3 \5 M& Z m 1 H+ g- z5 [& x+ w

函数名: cputs " V& T: ^$ F( n ?3 o1 s6 L3 h功能: 写字符到屏幕 / m5 S1 ^! [, ?5 D- m 用法: void cputs(const char *string); 0 ]' b. e4 }5 }1 U, { 程序例:

#include

int main(void) , u r: x! c i4 ?5 l{ : \+ I. W3 z; L( d& p# O. x /* clear the screen */ ( H+ H7 A! @ ]7 G+ @: Yclrscr();

/* create a text window */ / j- G/ g1 m; y7 m window(10, 10, 80, 25);

/* output some text in the window */ # t0 V# T3 D, z, Y% Pcputs("This is within the window\r\n");

/* wait for a key */ + n" N9 x# L* y1 T: n- j5 Ugetch(); / p( |* g) d& k+ wreturn 0; . _2 a' Y0 Y& k: ~! W: I5 k6 n} + G3 Z5 t5 g! g% ~7 _5 Q6 L6 i/ S0 G6 b% o4 u 7 u& Q2 Y; [5 d6 k! O& A- k

函数名: _creat creat # N6 l5 z9 D; ~$ L4 D) i/ `+ F: `功能: 创建一个新文件或重写一个已存在的文件 ; F0 v) G( y$ N 用法: int creat (const char *filename, int permiss); ) m0 u* R4 N, E, C程序例:

#include i: u8 P" ~1 p$ p" u& S! K$ Y #include ' B* Q7 [' w5 T3 t #include # N G3 F7 P* T9 J u$ r2 j: ^) U$ S #include

int main(void) / E5 `% |. m9 t- c4 l{ ( q+ F% b% ^% ^" h2 kint handle; 2 _; \( H l7 ~0 @+ n$ O1 b char buf[11] = "0123456789";

/* change the default file mode from text to binary */ " M" q) v& W6 }8 s4 Q0 Y _fmode = O_BINARY;

/* create a binary file for reading and writing */ ( F: v( V/ P5 yhandle = creat("DUMMY.FIL", S_IREAD | S_IWRITE);

/* write 10 bytes to the file */ , k2 N- M3 K9 |6 Twrite(handle, buf, strlen(buf));

/* close the file */ 5 @: L ~. V- J3 J; h6 W/ | close(handle); 0 e* f2 h+ i) S/ ^# [ return 0; D2 L, z$ j- @5 M% \7 k: l } 9 }. `; m+ k0 S* @. E

函数名: creatnew ( @9 h' f" U& t- a0 e" _功能: 创建一个新文件 ( d& a4 k- H p3 h4 G0 T 用法: int creatnew(const char *filename, int attrib); " u3 ^1 ~% @( b7 n( J* Q 程序例:

#include * f$ p$ F: F7 b+ R8 P0 A#include ; { v/ a6 A9 U# }& I" N; ^6 ]#include % m. m4 y) B6 T k& e' I #include 5 V( ^4 V: {- t5 j2 c4 t #include

int main(void) & ?1 A$ G% d9 U( u { - M3 n4 R9 ]) z7 G" [. f. zint handle; 4 y g- {: {4 q char buf[11] = "0123456789";

/* attempt to create a file that doesn't already exist */ 0 w9 U G9 F: ?; H handle = creatnew("DUMMY.FIL", 0);

if (handle == -1) 5 X9 i0 A0 b. v- N' qprintf("DUMMY.FIL already exists.\n"); , n' M. O& A& J- kelse $ o1 l+ E! U4 g! `2 t { printf("DUMMY.FIL successfully created.\n"); : k1 M6 E3 {" C: |6 T write(handle, buf, strlen(buf)); " }, t2 E% u! v( y, p, B: P2 B w6 o close(handle); 5 C& S6 X: p8 V) @3 f( E } 2 X% r; h9 ^0 j/ p9 K* c return 0; 6 w; N$ m$ d* f0 \1 G$ E} 5 o' q/ ?1 a3 M: j' z / Z; q9 Z C/ f# b% i8 R/ d2 u* l" ?& J0 u4 m5 Z" n! r: p

函数名: creattemp & z% P W# o* H( \ 功能: 创建一个新文件或重写一个已存在的文件 - w9 {. o0 B6 G用法: int creattemp(const char *filename, int attrib); 2 r( B& I0 U# j程序例:

#include . }* g, G+ U5 R8 W( l" a #include + ?: s6 ?$ {; @; q& F1 b3 P#include

int main(void) - e3 \4 P- p! r m9 K! p, V{ + z: F9 T, a, [7 M7 T* T* u0 R pint handle; # N9 v4 w8 @; _$ C5 Zchar pathname[128];

strcpy(pathname, "\\");

/* create a unique file in the root directory */ ! \" Y/ g( C, q# q$ Z& Z& a handle = creattemp(pathname, 0);

printf("%s was the unique file created.\n", pathname); 6 {9 C, [7 c9 P0 N5 lclose(handle); 5 {/ r# N' [$ k return 0; . N1 V& |1 S4 c+ m } ) B/ \7 X; Y9 C6 V ; k* n `+ V( o2 o4 [* a 1 z7 t6 K+ i3 ~ n* q

函数名: cscanf 4 k5 h* f' z4 p3 b1 k功能: 从控制台执行格式化输入 & }4 l. n; y/ C' q3 X8 |6 ?3 \/ r用法: int cscanf(char *format[,argument, ...]); $ g1 ~; \6 [% x3 n- g/ s9 L8 l, u Q 程序例:

#include

int main(void) ' J# S9 g |/ Z5 B' i' T! Y% c { 9 o$ k7 M& ~' T- o1 X/ d- ?char string[80];

/* clear the screen */ ' t$ _4 j1 P7 _9 [clrscr();

/* Prompt the user for input */ & _) |( \( M! L& ~ h% i% R- L& Hcprintf("Enter a string with no spaces:");

/* read the input */ ! p7 R Y4 J5 S! X7 x1 `2 k8 @9 b cscanf("%s", string);

/* display what was read */ / ?$ c& Z; [: |0 @0 d |, m" Zcprintf("\r\nThe string entered is: %s", string); 7 L& ^8 _9 ]8 F3 q return 0; 8 D9 M( E \" ]* G0 e B. X2 @ } 9 _0 ?% v" |% {! D 0 D/ o- Q8 J* `, x/ P( e$ {" T6 ~) |1 n! G6 v, a, j" T6 Y& ~

函数名: ctime / O( S4 g! q5 h 功能: 把日期和时间转换为字符串 # i; {# v9 D: ]+ f& r 用法: char *ctime(const time_t *time); ; S- J% M( f8 G 程序例:

#include ) E8 y5 F: _/ Y #include

int main(void) 6 H) Q" A6 Z5 R8 Z { ( X0 n h7 z& ^' u* t time_t t;

time(&t); - |' l8 t) ~' \) F printf("Today's date and time: %s\n", ctime(&t)); ) u' ~0 I; U1 K return 0; 7 k9 _" D' L( U! }+ Q6 r7 J c4 {/ B} 3 S3 E! e: E0 l# { 6 Y' n- T: Q' N9 U/ O ) b. O% u; ]; Q! {

函数名: ctrlbrk 5 \& c9 j8 o% r' ~6 C3 b3 _2 a5 P& b功能: 设置Ctrl-Break处理程序 7 w* a0 L; V& X3 c6 X 用法: void ctrlbrk(*fptr)(void); ! U/ R- U, l# t: o0 {3 ? 程序例:

#include & T3 e, M( D- O8 V7 H4 z #include

#define ABORT 0

int c_break(void) & I! e4 q$ }) ]) d7 l9 k- |1 F3 d { 5 Y* D. R) L5 V+ I3 S' _& x. C printf("Control-Break pressed. Program aborting ...\n"); - W3 l4 b7 e, L( W0 B2 @8 _ return (ABORT); 8 h& E2 g( u! M9 J2 |: O }

int main(void) " k# G- G$ m9 `0 u! j1 R{ ! R& S/ ]9 c) U; Y ctrlbrk(c_break); ) r6 z* p" \6 m) T# p for(;;) & P& k/ V% {( U: b. d& v7 O { ( C4 S& G% P0 B& U V; k& L1 T) Q. Tprintf("Looping... Press to quit:\n"); & w' a z. A1 d. n! j& j} : F0 `: |' t- e2 X return 0; & R" [$ F/ l3 H7 v0 F$ e' z}

作者: zjf 时间: 2005-3-20 20:26

[em49]

谢谢啊

作者: chenlk 时间: 2005-4-9 16:39
有价值！

作者: xxb1922 时间: 2005-4-23 20:12
这样看太痛苦了，还不如去下载一个专门查函数的软件，我就有一个

作者: xxb1922 时间: 2005-4-23 20:13
这样看太痛苦了，还不如去下载一个专门查函数的软件，我就有一个

作者: gssdzc 时间: 2010-6-14 13:02
还是感谢分享。。。

作者: hjl19890710hjl 时间: 2011-10-19 15:24
特别感谢

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