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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) 9 e4 m: K3 e8 O, V" e o7 _

函数名: cabs 4 _5 ]4 {# y+ Y5 j& B! Z& s. Z% G& T 功能: 计算复数的绝对值 ! Y3 O8 m2 a2 Q6 t( [! _ 用法: double cabs(struct complex z); `# c/ |1 g# I3 R0 U$ {' i N 程序例:

#include - V( F; t) E" ?8 [#include

int main(void) & y0 t2 h3 m1 U# P- ~5 O { & k9 C2 a2 I5 Tstruct complex z; 8 q4 G4 B+ |$ O# G0 hdouble val;

z.x = 2.0; 5 ^8 B/ s/ J8 H7 K* i/ p z.y = 1.0; : |- Z2 x4 q" Hval = cabs(z);

printf("The absolute value of %.2lfi %.2lfj is %.2lf", z.x, z.y, val); - l8 W$ R3 a4 a) W* R9 \9 j% h return 0; 0 t) K& y% O- ~- c } ' c8 d0 E' |$ X0 ?5 D( [! J * _6 a* e8 ~% f; s& N - `/ ]9 r6 I1 }6 m

函数名: calloc 6 a6 x; q: N1 O$ G) A 功能: 分配主存储器 8 q3 M/ O# p1 r' \8 x用法: void *calloc(size_t nelem, size_t elsize); 5 s, o% m* G( q: O程序例:

#include 0 {8 D" [( n+ f' k#include

int main(void) , \9 e( L+ ^; R) L" P2 E; ^) B' T{ / Y7 R ?7 A$ `5 R) Bchar *str = NULL;

/* allocate memory for string */ ; F/ W* }5 q& [3 R& A4 C str = calloc(10, sizeof(char));

/* copy "Hello" into string */ : ~& e( D$ h* N$ U6 b0 R strcpy(str, "Hello");

/* display string */ 4 U5 {9 Q9 g; |% |* ]* W1 Y printf("String is %s\n", str);

/* free memory */ # M3 \: f, t9 z( ^* X free(str);

return 0; : F( K% C ~& ]1 {$ {} 4 J. q9 O- N2 y5 G/ A6 N9 t6 x8 F; v! g2 f) T7 U, V* P* U' B ; M" i: |* o& n

函数名: ceil * y& X- t) E9 C- k 功能: 向上舍入 # ?( k* B9 j" l( [用法: double ceil(double x); & {# f6 H. \) O! E9 n6 Z0 s, f程序例:

#include 3 B" U* l1 i- A. g: O #include

int main(void) @! K9 Q. H( n+ N, f{ J1 k# J& t3 C! } double number = 123.54; . M' }8 y6 `2 y8 p, B8 d! w. odouble down, up;

down = floor(number); ; V a, c0 m3 q+ A$ L wup = ceil(number);

printf("original number %5.2lf\n", number); " {' N j6 R' z5 x F& Qprintf("number rounded down %5.2lf\n", down); * H y4 i7 ]# h jprintf("number rounded up %5.2lf\n", up);

return 0; " ?/ m+ W/ b$ g1 r7 A" g0 c} 9 d0 p# r- q* _; E ( h$ u; q3 ~9 Q: l/ b- w + m# y3 t7 O* V+ j! `

函数名: cgets 9 @8 Y6 J7 M! @1 o& `$ i+ d& B功能: 从控制台读字符串 # u, J: w: _4 v 用法: char *cgets(char *str); # o! s2 _: `7 s 程序例:

#include 2 `7 ?4 Y7 f7 t/ m3 v #include

int main(void) 1 M0 S9 t- F, h0 z{ 7 H$ `. j3 E# ~: B+ lchar buffer[83]; 8 L7 X$ p* B# c Zchar *p;

/* There's space for 80 characters plus the NULL terminator */ 8 `8 |& M9 C6 [% J5 V( H buffer[0] = 81;

printf("Input some chars:"); 3 ~. S9 X7 {: w$ W/ [ p = cgets(buffer); 7 S% a v4 {% \. i5 i6 S! iprintf("\ncgets read %d characters: \"%s\"\n", buffer[1], p); # b% f( F& N) H* Pprintf("The returned pointer is %p, buffer[0] is at %p\n", p, &buffer);

/* Leave room for 5 characters plus the NULL terminator */ : C: {. C$ K& P* \ buffer[0] = 6;

printf("Input some chars:"); / h$ s' K- q" L8 Dp = cgets(buffer); 4 E3 l1 J2 S" k% g7 ? bprintf("\ncgets read %d characters: \"%s\"\n", buffer[1], p); 9 R' q3 a4 B/ n3 {4 v0 ^9 i* Hprintf("The returned pointer is %p, buffer[0] is at %p\n", p, &buffer); 0 `& S7 d/ P+ F; b) V return 0; 7 X, w9 i" o8 A- d r6 I8 P7 ^ } ( D& }* U$ i5 p# P, s! D7 H $ c; R2 \1 K; A2 J0 S& t/ M H2 W' T8 e2 v4 V7 q9 E) Y

函数名: chdir M9 B1 O; m+ l) H/ m D 功能: 改变工作目录 , ]. k O+ E, a, y) p r 用法: int chdir(const char *path); : ~5 c- z4 U E" s$ q- x% h程序例:

#include " |7 z% X8 D* i6 J4 w% B6 x#include 2 t* t* _! O, ~* \5 D( T& p#include

char old_dir[MAXDIR]; + N' S" y9 @, H/ l char new_dir[MAXDIR];

int main(void) 4 n8 J5 t+ t( U3 g. a: y6 k { 9 s" t8 j/ E' m. W8 g9 R( G2 D if (getcurdir(0, old_dir)) * e, x4 K8 D8 w/ x+ l& L, \, C2 h { " b# v! [4 G2 y5 \# @3 V5 G( Pperror("getcurdir()"); 8 {* S% b9 C, Z$ Aexit(1); ?! G6 `% L0 {9 l' K: y M3 u O } , V! ~, T; ?1 q3 p4 q7 A printf("Current directory is: \\%s\n", old_dir);

if (chdir("\\")) ! y n; G0 u* c) c! f% [) p { 3 G1 f o2 @' j# O$ e) Xperror("chdir()"); 4 ?( [' A" o; T+ j/ y! Oexit(1); . Q" F1 Q8 ?. D0 ]& D: H' U* }6 s }

if (getcurdir(0, new_dir)) $ h- c6 {/ P" O2 u{ 5 E, n2 b3 i( B! B# r2 S% d5 kperror("getcurdir()"); 3 f3 a2 Q& n0 p L( xexit(1); ) ~3 K4 z& Q& I: ?- m" _% |& ?% A( T} & k( V4 ]% R( _- b: Tprintf("Current directory is now: \\%s\n", new_dir);

printf("\nChanging back to orignal directory: \\%s\n", old_dir); 7 G* r: B$ L- a if (chdir(old_dir)) , M, k1 B. `; O0 N! B- [( @3 x{ & V* O; u( d7 C1 {8 t( n, f perror("chdir()"); - N7 D& \/ t4 ]; Q exit(1); 9 v' I& ~. w' Y; u. Z }

return 0; . K+ [, M4 }% B } $ s8 y0 Q. I' K8 z; f: [2 A6 s+ L" t9 Q5 [3 X0 o% F

函数名: _chmod, chmod + k% M4 q" r; q* h 功能: 改变文件的访问方式 6 @ ^; s" |4 W# f4 n0 p 用法: int chmod(const char *filename, int permiss); 9 `$ P' z: Z Z3 O( B0 p程序例:

#include $ L: G( v$ ^# P6 G4 q) y#include ! \6 I1 ]- S( I #include

void make_read_only(char *filename);

int main(void) " [7 Q/ `# C) i6 } { 2 s4 e0 _- d5 C$ G5 D% J+ emake_read_only("NOTEXIST.FIL"); $ r4 w* F' a$ ] make_read_only("MYFILE.FIL"); R# v$ U% t7 P/ r# H+ u3 a return 0; 8 K6 E$ d( S7 U6 i/ O, l0 P; f}

void make_read_only(char *filename) - e3 x( T5 n, v& I/ _) y3 p# ~ { 7 y) G/ B5 H4 Y( U. T int stat;

stat = chmod(filename, S_IREAD); 2 o3 J* F, n6 |0 Q! [) P6 ` if (stat) ) h/ V/ ^4 ~. k3 a6 hprintf("Couldn't make %s read-only\n", filename); 1 V: U3 Z) b" O. Z! W* |! d# helse / I+ y2 ~/ M& I) y0 [0 _: v( \* s printf("Made %s read-only\n", filename); 3 r# Y* c8 ^" R} . V7 g- `& F$ G `" W+ n % o! [# A/ g7 M/ J" O' t# p. e4 R n# K$ }

函数名: chsize 5 [ E7 _4 C8 ]1 e/ E3 [* H$ k+ S 功能: 改变文件大小 ( j: k1 E) l% g; j) O5 x, s& U用法: int chsize(int handle, long size); 3 q- K a0 F( {# S) W程序例:

#include / d; r B( R9 F) k5 _1 Y# R, c#include 6 K6 v1 A) o% l1 r7 R#include

int main(void) " f2 q3 ?- r& Y6 V# h4 }/ ]6 L! }9 [$ q4 H { ! {+ V6 {% z8 r7 M int handle; 8 F) F4 o* \. A& B& bchar buf[11] = "0123456789";

/* create text file containing 10 bytes */ ( F) p& G: r5 {handle = open("DUMMY.FIL", O_CREAT); 8 x+ \5 |" ]$ E, ^/ X$ n8 _ X write(handle, buf, strlen(buf));

/* truncate the file to 5 bytes in size */ . J- g j& T& ?chsize(handle, 5);

/* close the file */ 5 Y) w! P3 Z4 Y* U3 G* T- O+ ?6 B close(handle); & W9 Z5 T2 L4 Y6 f* k* S+ `return 0; / I; a) P& [, }! x6 _} ( h( F F* _# I# m9 g: C 7 k& A* O9 G3 ]6 U2 e

函数名: circle % J6 v S. l+ h9 d* C, |4 q功能: 在给定半径以(x, y)为圆心画圆 " ~) a1 f8 P( R* m \用法: void far circle(int x, int y, int radius); 7 w; v& q( O9 m7 ?$ U1 F9 ?) ? 程序例:

#include 3 S5 Y8 a; ?5 O2 { #include / I; V6 Q; p( y3 e e, b5 m2 e #include * s: c8 Y# O3 m# p# ~ #include

int main(void) & @# g) {. F; H { $ [' a3 g; l7 l! w \! ^- ~ /* request auto detection */ : h4 E9 j( M' { o" |0 r3 u" y$ X int gdriver = DETECT, gmode, errorcode; , v- U: h" c! j; h* sint midx, midy; 6 b0 g2 f y- x7 x' Uint radius = 100;

/* initialize graphics and local variables */ ) W1 _1 t& p h% }initgraph(&gdriver, &gmode, "");

/* read result of initialization */ ; j7 P( B; G# v6 \$ L errorcode = graphresult(); + b2 D/ k; d3 }2 B( H if (errorcode != grOk) /* an error occurred */ ) _) S# c. _5 a, n' B{ 6 o7 N$ s$ f4 `' G8 v. |- x: J0 Kprintf("Graphics error: %s\n", grapherrormsg(errorcode)); ( V1 m& W1 v' i/ F- ~" { printf("Press any key to halt:"); " G) f( @6 I c0 ]4 kgetch(); 3 R& M: }% Q: Z2 h exit(1); /* terminate with an error code */ * O9 w& F* e1 f' @& |& w$ P) [ ~. K2 l}

midx = getmaxx() / 2; ) ~6 [& h3 ]& P' h8 C tmidy = getmaxy() / 2; 2 O1 u# X8 u! o/ b; xsetcolor(getmaxcolor());

/* draw the circle */ + L4 C' Y9 J" o; h8 Bcircle(midx, midy, radius);

/* clean up */ & i/ P- n5 ?5 M( f8 vgetch(); 9 {) j8 O9 S& p0 {1 }& [8 P! v" fclosegraph(); # H' m3 Z) I# n: C: hreturn 0; " y/ W7 [% o, ?6 G} V& N" O" Q4 W" m 8 S3 L: J1 E9 I9 E: k0 b- t) u' D1 M9 M9 d0 p \- H

函数名: cleardevice / d0 Y8 `; Y6 P- o, Q6 e/ Q) W功能: 清除图形屏幕 + Q* ~. l' W# L' V% p% y用法: void far cleardevice(void); + u9 `- w, ?' k7 m& j 程序例:

#include 0 k/ R. Z6 L4 ^#include $ f7 Y% Y* k6 U3 ^) y" N/ u #include ) i, f2 N8 C* n: F$ U+ e3 |#include

int main(void) ' q' H$ u% f2 T6 m$ C{ 4 O/ [% R3 t; r' i3 M4 X4 H$ z/* request auto detection */ 1 j& l) y6 Q# ^" i) g. i0 D" k6 M* N int gdriver = DETECT, gmode, errorcode; 7 C% x. ~' B8 X+ z1 B, g- t& @0 c int midx, midy;

/* initialize graphics and local variables */ 6 i/ u0 I- Z+ kinitgraph(&gdriver, &gmode, "");

/* read result of initialization */ * n; L0 r& `" W. b; p3 o errorcode = graphresult(); 2 |; l5 Q+ l1 ~. Kif (errorcode != grOk) /* an error occurred */ - h! W9 S9 {' q3 \$ u1 e* [ { 2 O) Q2 f' u4 ], D4 X printf("Graphics error: %s\n", grapherrormsg(errorcode)); 2 _; H0 E% N+ R3 Q* C2 A& wprintf("Press any key to halt:"); # f( A j# _( Wgetch(); , l# L" j( Z$ l) t- V8 oexit(1); /* terminate with an error code */ 8 i' `2 u6 }- x2 p+ Q. o, c( \; V}

midx = getmaxx() / 2; ! r1 x' i6 F) P* k0 n { midy = getmaxy() / 2; 3 E' q5 d, s- G/ X, n' ~% o8 M! z8 C setcolor(getmaxcolor());

/* for centering screen messages */ 3 H: ?' W7 n( e8 ssettextjustify(CENTER_TEXT, CENTER_TEXT);

/* output a message to the screen */ % a. W0 `8 X* G; I" _/ [. y. J outtextxy(midx, midy, "press any key to clear the screen:");

/* wait for a key */ 0 h6 s0 Z) S& ~! ^. U getch();

/* clear the screen */ 3 c# X" a7 h" I9 F7 O9 L cleardevice();

/* output another message */ ! \8 u% W8 t4 z# youttextxy(midx, midy, "press any key to quit:");

/* clean up */ + Z: q( I# r/ F getch(); 2 Z$ ?2 J$ o. b/ {4 H) v closegraph(); ; F- s2 K3 W! j5 qreturn 0; + r6 e2 {" A6 e6 S } " I1 Z' k) q9 g2 y 7 X8 M' @/ r+ @3 v( r. u% N 8 {; ~- f! r: D1 X4 w' ~- F# l

函数名: clearerr ! c: c8 l3 J* P I功能: 复位错误标志 - V: z0 {0 L3 r9 g+ D1 l+ O 用法:void clearerr(FILE *stream); ) A% [. x z) j, ?, d+ l 程序例:

#include

int main(void) 7 c$ u: a: F) Z; {7 l, X5 D{ % A+ |/ V0 c1 s7 ?$ H FILE *fp; . o2 Z& b' Y: Schar ch;

/* open a file for writing */ / M. H: e9 e0 ?) d- J fp = fopen("DUMMY.FIL", "w");

/* force an error condition by attempting to read */ 8 R7 L$ }7 i+ {& V3 U8 b" {ch = fgetc(fp); + ]) K( I2 L9 m; ?1 T3 s8 Fprintf("%c\n",ch);

if (ferror(fp)) 6 [$ e' i! k2 ? { 7 D4 J) P. y6 u) Y1 h /* display an error message */ + T) v8 |+ k/ c8 t4 ?# h( Y2 n5 z. Pprintf("Error reading from DUMMY.FIL\n");

/* reset the error and EOF indicators */ " q( F- u; }" V2 a- qclearerr(fp); " {' v$ D4 a# E8 }5 w3 `}

fclose(fp); ( e# N4 C: H" qreturn 0; + r E: f3 {' [; `' W9 g: C6 ^" ] } ) `6 k \6 m5 p2 Y- Q- q 8 ?7 j5 m6 T6 m K: l2 J8 g6 |* t! V& R* `4 } o0 {7 k8 F/ D) Z2 C6 Y

函数名: clearviewport 3 S6 D/ V0 {. j/ Q 功能: 清除图形视区 ) H2 o2 _- r) p( \& G$ b; I用法: void far clearviewport(void); 8 r$ @ y5 w0 m0 k程序例:

#include - w+ m+ w7 F+ m- @6 Q6 Y #include + ^2 X, O' Y( H. c) {/ `* N#include % \. D* R! P: _) k( _8 V#include

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

int main(void) % ]7 B7 h5 e5 p3 t Y3 f7 x { ! K- c7 M/ ]! W. A. \ /* request auto detection */ 3 z" b3 E, M: S- I, {& D int gdriver = DETECT, gmode, errorcode; 1 e/ t6 W2 Q( K( `5 A int ht;

/* initialize graphics and local variables */ 0 g6 B" X3 n& v; K) L- v" Ainitgraph(&gdriver, &gmode, "");

/* read result of initialization */ 4 q& {) }' I; K. H: h1 W7 m errorcode = graphresult(); 5 T4 t, \2 m7 Q* C. ?if (errorcode != grOk) /* an error occurred */ 8 Z) D) S e( g7 u T j% D{ 5 U" Q9 O1 b4 q0 B5 X+ ^( w4 F printf("Graphics error: %s\n", grapherrormsg(errorcode)); 6 L) Z. z9 \8 t9 Zprintf("Press any key to halt:"); " [7 x1 w: r u9 Cgetch(); ) K5 F" t8 a( h' S7 Y) R5 x, rexit(1); /* terminate with an error code */ 6 r3 E8 J# f5 ~% m+ v" Q }

setcolor(getmaxcolor()); , r. o$ Q: G3 q: m ht = textheight("W");

/* message in default full-screen viewport */ . }; {% f$ X8 @7 ~% L& T outtextxy(0, 0, "* <-- (0, 0) in default viewport");

/* create a smaller viewport */ . C8 l6 r/ x6 U1 z3 x( ` setviewport(50, 50, getmaxx()-50, getmaxy()-50, CLIP_ON);

/* display some messages */ , g0 U2 j/ X9 V% t# P0 \' k( x& Mouttextxy(0, 0, "* <-- (0, 0) in smaller viewport"); + J# h% m2 V' b+ o2 E' R4 | outtextxy(0, 2*ht, "Press any key to clear viewport:");

/* wait for a key */ ) t! X1 m# D( Z8 N. ], i getch();

/* clear the viewport */ ( ^+ M) k7 r' e: E clearviewport();

/* output another message */ ( x! n( x. O I& H$ Q$ nouttextxy(0, 0, "Press any key to quit:");

/* clean up */ : p# c$ s! L# z" |getch(); 0 d$ H# y5 _/ P# h4 |& I closegraph(); 0 H4 r4 T8 u3 m2 i; Y/ c! [return 0; 7 Y8 x: C+ K2 Z3 i% }2 m} ) r% r/ D! p8 { 8 {8 D& j: x. T6 U # q7 J5 r" W% m0 \" a

函数名: _close, close ) H ~* O6 ~7 c/ `' i7 @# D' d功能: 关闭文件句柄 " I/ J& i7 @2 F8 b" b: e9 P2 ^用法: int close(int handle); * v! i5 r5 f! R5 H( A 程序例:

#include " {+ c. e7 k" E, S#include 3 U) U6 c7 M" o" Q8 H' P: z #include 0 h. ]1 [! C. b; L6 e% S. N#include

main() $ C; o$ B8 I) R7 n; \. M { 1 Z$ e/ \0 l6 K4 Q' q# I! Sint handle; 5 ]0 M( Y$ r# _: Y! B+ f char buf[11] = "0123456789";

/* create a file containing 10 bytes */ # B3 e9 W, M1 Q4 I. Ghandle = open("NEW.FIL", O_CREAT); 5 l% L/ \9 `# O7 `6 }$ aif (handle > -1) * F* x& \' u$ v9 h{ ) N1 n/ U" m: p8 `$ [+ fwrite(handle, buf, strlen(buf));

/* close the file */ : V0 R) M% L) S3 f0 R. T7 Yclose(handle); ) o* f: g0 T& o% X( D} : |6 F3 [ W. z3 ` else : I0 E/ @3 m" ~: F6 [{ % ?8 l# t, l' C5 v2 Fprintf("Error opening file\n"); 7 ?$ q0 h* W+ Z* X; y, w$ |} 6 H' z5 K C1 nreturn 0; + c" u& v, `% ]9 X' y } 4 _+ S3 Y" F( ?0 _9 p5 ?7 i4 G& i4 N$ q! J$ D u$ S + o8 X }: T' u# ]. @

函数名: clock / \2 n2 k$ ?' b' N" m8 [* ^功能: 确定处理器时间 ; B* f$ K0 `5 V+ H用法: clock_t clock(void); / j4 u! Y& J$ T. f1 O* N8 c$ L( R程序例:

#include ' ^+ X' e z$ s! u #include 5 C2 Q8 B5 E, p' S- |# W' R4 ` #include

int main(void) " S/ |; ?0 Q. u7 {" o2 r3 i{ 9 L* i) A2 D2 q4 Z4 ?clock_t start, end; 2 D+ o) l) s+ X0 nstart = clock();

delay(2000);

end = clock(); 3 i# z$ K( Q v# w9 ]/ ?$ [- O. y6 dprintf("The time was: %f\n", (end - start) / CLK_TCK);

return 0; : D& \1 k, Z( z* m4 ? } 5 z. y C- W9 o$ G! C/ Y8 v5 Q/ M , H4 V7 U2 F* L9 s6 _; R

函数名: closegraph 4 l" p* m4 F4 N 功能: 关闭图形系统 ( k- K( m1 n7 q z 用法: void far closegraph(void); " w1 `! x5 _8 N! w# ], I% i程序例:

#include * p, M; f9 P! b #include & H% A; P4 A8 [ D#include 5 W: _! Y/ r6 e* h0 K# Q. j: B#include

int main(void) : `3 i$ q& k. t& t# c4 [# f { 0 ~% M- m) _: j* a; G/ s /* request auto detection */ 6 ~/ K2 g2 Y2 ~int gdriver = DETECT, gmode, errorcode; 4 Z7 H8 U' c/ j- T4 X+ ~ int x, y;

/* initialize graphics mode */ 9 @* a& H& C4 ]" M( {+ m1 g8 ?& @ initgraph(&gdriver, &gmode, "");

/* read result of initialization */ 3 k+ I$ `0 E# L, b errorcode = graphresult();

if (errorcode != grOk) /* an error ' {) V3 A' U: D; Toccurred */ ; r; A, Z* r: I6 v* O8 _{ . q. D1 D3 v2 w! G# z; g printf("Graphics error: %s\n", grapherrormsg(errorcode)); 3 O* z8 l, s; W( c/ I U5 Q0 N printf("Press any key to halt:"); 1 M: y2 @7 j* U. ?4 J0 \getch(); & L0 X& r: R& d+ Y7 a2 F+ Y exit(1); /* terminate with an error code */ 7 J! l: Q0 O. q. {# j8 H. x" ~ }

x = getmaxx() / 2; " T2 q& Z' k+ |y = getmaxy() / 2;

/* output a message */ 2 v; U7 W8 M0 c# F+ Q/ g) \ settextjustify(CENTER_TEXT, CENTER_TEXT); 4 A. j( Y0 {. Y* ]+ z outtextxy(x, y, "Press a key to close the graphics system:");

/* wait for a key */ ) ?2 z7 d6 R. A1 m+ j# i getch();

/* closes down the graphics system */ 7 Y* _- d: }2 |& jclosegraph();

printf("We're now back in text mode.\n"); . ?# T, y! G$ c/ w printf("Press any key to halt:"); % X% S. Z& A8 |& l9 i getch(); 7 S% V% K% o$ Areturn 0; + m- q( {& p+ q* L% P: L; V1 I} " Q" N% ]8 h# C4 w9 g; k 9 o+ a9 i6 Z$ L+ @ / ^- k- Y( b/ E% D: }) P/ i1 q$ c

函数名: clreol : G$ D, c1 {* b" h& Z- t' i% U- A5 I功能: 在文本窗口中清除字符到行末 . K" H3 @; U5 j- r2 I 用法: void clreol(void); 3 s# b7 }5 x& p9 x程序例:

#include

int main(void)

{ 9 ]6 a- h6 a6 O3 I4 ]6 [clrscr(); % c9 M+ J0 K5 e9 b; Q& Bcprintf("The function CLREOL clears all characters from the\r\n"); , G& J* E2 e+ F3 ~, C5 X cprintf("cursor position to the end of the line within the\r\n"); ; W6 U! v, S- H( I4 @8 D' W cprintf("current text window, without moving the cursor.\r\n"); ! j) |" n( q1 @2 ~/ c5 P* Z cprintf("Press any key to continue . . ."); 8 ?8 @2 g& S& D# z' z1 a6 _4 H+ c gotoxy(14, 4); ( L2 M' D$ }! \" X; \ getch();

clreol(); % A+ p; L& Z6 S: e. ggetch();

return 0; 1 V. E# ?$ S2 a- O} - _: y) x' q3 Z7 Y# {9 n + _% H0 T. |7 [$ |; X # ?" }' A/ C4 M, H5 u+ G0 q* {

函数名: clrscr ( `. `; z8 H, Z/ Y0 q7 e 功能: 清除文本模式窗口 $ e, {- P* w1 g2 b2 s9 t用法: void clrscr(void); 4 {7 ~9 Y4 l* k 程序例:

#include

int main(void) ) u$ n2 }8 I8 ^. ~4 B7 h. ]8 y{ % x% d. h+ L# q2 d6 D/ C int i;

clrscr(); 6 x1 S8 \6 u# [4 n1 u8 L2 vfor (i = 0; i < 20; i++) / i7 u- r1 X7 Z$ U# j9 R2 xcprintf("%d\r\n", i); ( z: R" E/ v, p+ R) N3 g cprintf("\r\nPress any key to clear screen"); X2 F. g, e& Z/ f Cgetch();

clrscr(); " j' G/ w. b3 v, Q5 | cprintf("The screen has been cleared!"); + E2 q: ]( p9 w) _getch();

return 0; & `4 u% Z- h% J, V* l } 7 h! w* U) G- m, M9 [ - s/ B+ r- F3 s- _! _* y5 L: Z) t2 ~. i9 W/ |5 I

函数名: coreleft # ^: @1 M8 Z; i. v0 o7 ? 功能: 返回未使用内存的大小 . D$ [* a/ O3 G. j3 s 用法: unsigned coreleft(void); ( e- v# Q D; Y8 S/ }2 E程序例:

#include 6 L& ]8 Q* H6 b) j& i/ f #include

int main(void) . A7 m, h3 B. }7 S { 3 X* i! I. L, I# @ printf("The difference between the highest allocated block and\n"); ( E" J! {6 C0 C% c% {* v6 eprintf("the top of the heap is: %lu bytes\n", (unsigned long) coreleft());

return 0; ! s6 m. M& [ k$ Z H; a K, p* h! F7 ]} ( G. F q3 J4 ]3 N2 b- V( r

函数名: cos 0 D# _. a. j8 W6 d2 a 功能: 余弦函数 - |; J' n; `! v" T) q2 ~ 用法: double cos(double x); 9 n; Z9 H( U# u. G 程序例:

#include * w; m" \: J2 N; U) a! z2 P! y#include

int main(void) 7 z9 q5 t8 |( n+ `- U7 \{ 2 p3 W( ^' s" t b5 ?% u( @4 | double result; & q1 b9 o) ~( k0 {* b double x = 0.5;

result = cos(x); . X. T7 X- ?# `. O( j4 K2 S( Y0 dprintf("The cosine of %lf is %lf\n", x, result); # i" q2 C$ a) u" N return 0; 4 a+ l& B P4 t' X" I- e } 7 b+ J6 L. v( ~1 p4 X( V! i3 R # q! s& T' C/ T6 K. Z; ^% | / ?; V' a- M# B" \% Y1 V) ?

函数名: cosh % L# E$ @' b! K0 T B2 r J 功能: 双曲余弦函数 ; c0 \% }8 N! _: j" g用法: dluble cosh(double x); , q2 R% [1 G: J; K- V2 j 程序例:

#include # {: l; g) q2 H #include

int main(void) 2 Q- H9 c# ~/ J# n0 C0 c{ 0 Q1 X9 e' x+ s: a6 s; z% Ddouble result; 9 q4 r! _- @8 c& ^7 e1 m; r double x = 0.5;

result = cosh(x); 4 Z+ s% C. g7 _ printf("The hyperboic cosine of %lf is %lf\n", x, result); 1 z$ f V2 Q* Q8 Y: R: Preturn 0; 3 n+ h8 g+ |9 ~+ x: _ } & @, O' E' R; _, O0 @. c7 i* p. R 0 s4 D& ^: X j0 p + O6 `8 S8 @ q% A3 j; N

函数名: country 1 @# k$ [. t- d功能: 返回与国家有关的信息 - D: B) s! m8 }& J" @/ V( k 用法: struct COUNTRY *country(int countrycode, struct country *country); - ?( j2 j9 t, i- g1 K) C' P- u9 E 程序例:

#include ; I7 u7 f z4 X2 C3 j# f1 q' W#include

#define USA 0

int main(void) # ~- D9 Q7 l' q% }* P3 A{ 3 H: ?8 _# G ]! V+ |% l; F+ Vstruct COUNTRY country_info;

country(USA, &country_info); ) {4 U" |" o; Z7 X/ Q4 aprintf("The currency symbol for the USA is: %s\n", 8 r5 Z2 n K$ R) b3 L2 _country_info.co_curr); 9 S. h8 X( h; J+ W- Q# Lreturn 0; 0 m$ ?4 o! T' n; a% F7 F} ) I& |! K7 H& W3 N 9 e3 u4 P+ p( m0 [, q0 R ) ] t% w* O* N+ D- \0 n* o

函数名: cprintf ; H5 ^: D3 R" q3 A0 `: E! @% P) m2 I' q5 n 功能: 送格式化输出至屏幕 $ C7 m- h u) f: D+ w8 X 用法: int cprintf(const char *format[, argument, ...]); / Y( E9 ?# S9 P+ w- n程序例:

#include

int main(void) ) [. u C3 T; a0 \$ y { 9 F$ O+ m7 F9 X /* clear the screen */ 3 I* u3 F2 K: s5 Uclrscr();

/* create a text window */ $ c" M) v; s4 X1 n* Q' i window(10, 10, 80, 25);

/* output some text in the window */ A7 r* O9 Z6 g: W% w$ F cprintf("Hello world\r\n");

/* wait for a key */ % @" J V( M$ t5 p, Z+ J8 Tgetch(); 1 O6 W+ N" c Y$ J4 X return 0; # Z- ?6 o- K6 C2 z2 u } ' r/ [7 L' c6 v9 W* T @) r 3 o0 \7 g: G6 q6 z % U4 s4 U6 B. S5 V- w9 |

函数名: cputs - D9 O4 A: f. z; `1 H' U功能: 写字符到屏幕 ) O) J9 v5 Q3 d: L& C$ x5 W( Z+ ^ 用法: void cputs(const char *string); k( I3 L( q, S7 f 程序例:

#include

int main(void) . [6 N$ w- c2 t{ ( T* C) I4 H, ~. i /* clear the screen */ $ h( h! Q' s. I4 j clrscr();

/* create a text window */ . V' j" C9 [0 R5 q x3 L window(10, 10, 80, 25);

/* output some text in the window */ 3 X( S7 N- J) B( b2 S3 u6 o1 ]# U8 w Tcputs("This is within the window\r\n");

/* wait for a key */ " u- |/ x2 `5 X7 k. l getch(); 8 e' K3 D% Z( K: W) b. J4 }return 0; % B! W6 ~$ D8 ]2 L} % b% ~' f& ~' e# z( E0 e$ l# h0 ~$ @' x) g0 ` 4 Z2 l- y, D+ A( | ^* Q

函数名: _creat creat # P/ I3 r0 `2 A, G% L8 w6 o3 | 功能: 创建一个新文件或重写一个已存在的文件 1 T9 G- n$ C b% I6 ~2 ]用法: int creat (const char *filename, int permiss); 8 ^% |/ P; ~" L' x& K. Z/ x程序例:

#include # Q' I& r% B. g# { w% o7 Z, X) Z9 n#include 4 F& j' f" f, p$ l) O0 m- ]#include 3 w4 v W4 l7 Z2 \3 o- ^, \#include

int main(void) 4 P, M7 R$ e4 c3 G' R{ 0 ?) V- l0 K0 O7 y: ~* e int handle; % ], N" x d( W o+ achar buf[11] = "0123456789";

/* change the default file mode from text to binary */ ' e/ N1 f4 D" p_fmode = O_BINARY;

/* create a binary file for reading and writing */ # R4 \( g! K* H7 Z4 m2 O" Y handle = creat("DUMMY.FIL", S_IREAD | S_IWRITE);

/* write 10 bytes to the file */ 9 w" v0 |: x, qwrite(handle, buf, strlen(buf));

/* close the file */ { J0 a1 u6 B" r4 M7 r close(handle); 6 {* G4 S/ b' T9 }1 c, wreturn 0; ; y$ |5 S0 Q7 n3 g8 {0 _+ P/ c k0 P} 6 s' Q8 h1 {. o( s$ d

函数名: creatnew & t4 c/ W9 [6 D( G7 d. T 功能: 创建一个新文件 ! e D6 F* ^. H6 k用法: int creatnew(const char *filename, int attrib); ; W) [+ x1 O( s( i- \6 y程序例:

#include / ?2 ^/ D" L8 {- w D: e' s#include 5 v" ^ u V- q# G0 n2 G#include 8 N3 l6 q8 f" f8 A#include , e: {7 q3 r$ e7 G) ^#include

int main(void) ) x: ~9 z6 Q# q$ k# u. F$ T { 7 u: p5 f7 s1 M" p# y. W: B" w int handle; 5 w2 Q( Z% ]- _9 t; Ichar buf[11] = "0123456789";

/* attempt to create a file that doesn't already exist */ * b* B+ u+ O- ~4 phandle = creatnew("DUMMY.FIL", 0);

if (handle == -1) # ?; `7 U8 e8 z# Bprintf("DUMMY.FIL already exists.\n"); * S+ G% Q* z$ g* d2 ]else , l, v; f4 ^- ~/ p2 N! Z { $ |, c7 M+ g" t# @# Eprintf("DUMMY.FIL successfully created.\n"); 4 d' `+ C0 b" K' H) K+ F( E4 B write(handle, buf, strlen(buf)); 7 m, c6 W S! `2 g& Aclose(handle); 3 |8 @& H+ c7 `+ K% E# r! {; M} ( X5 ]8 B1 K9 A# [( j! Zreturn 0; " w1 x* B& G# O$ H& J: y1 M! X4 W } $ G1 O! l, I/ v , P& I0 _" ~+ v# u8 x0 |" y$ t% p6 F/ m* _" ~" L

函数名: creattemp " X" x( [4 v& |* `, I功能: 创建一个新文件或重写一个已存在的文件 $ h W. H4 S% l) ^( q) m- Q 用法: int creattemp(const char *filename, int attrib); , w+ p. u6 M1 v% u 程序例:

#include 2 y `* y# L4 w& ]+ U4 K7 L3 E #include ) x/ l( `) J, W& U& _#include

int main(void) & g$ o7 {7 }8 T4 q! s( h. h! s! j{ ; E# E- `; A9 z0 K+ Xint handle; 4 `1 L. K: Q1 p5 @3 s! q char pathname[128];

strcpy(pathname, "\\");

/* create a unique file in the root directory */ 6 [, C4 Z4 W6 P% _' v% T3 Y1 T handle = creattemp(pathname, 0);

printf("%s was the unique file created.\n", pathname); $ U) @0 J+ r& z. f2 bclose(handle); % k4 L3 q o! m3 qreturn 0; ) ~ _1 ^$ e9 ~2 _3 Q# d) D/ f } . W* o3 Z" \9 a/ d7 l9 w' ?4 B! ~2 @! W* G9 p# X/ R* n8 N ; V7 h- `: X( V; a

函数名: cscanf - p, K2 j/ |# g1 z# G7 F 功能: 从控制台执行格式化输入 ) \4 E8 Z$ ~$ G6 Z$ X用法: int cscanf(char *format[,argument, ...]); 2 i# y! \8 f+ u( w( _$ V 程序例:

#include

int main(void) ( n" ?4 Z, u$ g2 ^5 R% C: @' f{ " c& A1 B a: M ]5 gchar string[80];

/* clear the screen */ 8 [6 v+ `: \6 w9 W" m& W clrscr();

/* Prompt the user for input */ : D; {2 B9 X" i% Q9 ~' ?5 d# wcprintf("Enter a string with no spaces:");

/* read the input */ 3 P/ }) a, h4 {9 o! V; X" Z' n, q1 @ cscanf("%s", string);

/* display what was read */ ) R1 v4 K \7 o* Dcprintf("\r\nThe string entered is: %s", string); 5 l8 h4 u! `3 c! Greturn 0; r; |2 g- A2 d3 L3 F} ) o- R+ ^) g, y+ w" @! X; | , d6 s7 B1 J- Z! X$ f2 \- x! T% }4 |* u ?) m7 L m

函数名: ctime / p' \7 P, p. Q+ M% B) C4 Y5 ^; q功能: 把日期和时间转换为字符串 ; z1 u) }+ }6 h# h( m; K用法: char *ctime(const time_t *time); 7 ]/ F( P# _* y程序例:

#include 9 r" d4 w3 G) n( K% w) R3 C) v#include

int main(void) 4 f! l. D( T1 Q6 m9 N{ ! B: \3 v: E( `, N( ]7 N" ^9 D: S time_t t;

time(&t); + [6 g& s8 c: ?1 C8 B3 x yprintf("Today's date and time: %s\n", ctime(&t)); ) @% D# a; w1 e1 W6 Dreturn 0; & x9 O$ O2 I# j" _) F$ K M% ]} ( F. J9 f; T# a/ d F! S* x" `8 A/ z8 u& O2 h. r4 A a; P3 {' h- d7 S

函数名: ctrlbrk 5 S9 Q# v/ v( [( M4 q; h$ v# H功能: 设置Ctrl-Break处理程序 ) D& Q, Z% D8 z8 M用法: void ctrlbrk(*fptr)(void); ) o& g6 h% I2 z1 B- ]程序例:

#include # G5 ]7 I+ {+ X5 [3 [ #include

#define ABORT 0

int c_break(void) # B0 N* V( s5 x t' x5 A' u { 3 l9 Y5 ~! N: l9 A; p printf("Control-Break pressed. Program aborting ...\n"); ; F' ~5 n" v# a* E7 ^- o4 Kreturn (ABORT); ! o( U7 f( n& f}

int main(void) " B! ^( p1 I5 i+ \ { ' Y+ y4 E* `8 d ctrlbrk(c_break); 9 [+ ?$ D/ x, G( R4 H; P) k) pfor(;;) 1 z. V2 s- I# a/ \ { . z; I4 d% m) F0 \8 X printf("Looping... Press to quit:\n"); X& v0 P6 @* I, n0 Z, J( d1 ^# @7 E, O} ' k9 T0 C* j' H return 0; 0 I* ^. ]$ M5 y% E& f6 Q! S, y }

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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