查看: 1829|回复: 0

函数大全(q,r开头)

字体大小: 正常放大

韩冰

823 主题	3 听众	4048 积分

我的地盘我做主

该用户从未签到

电梯直达

1^#

发表于 2004-10-4 02:55 |只看该作者 |倒序浏览

|招呼Ta 关注Ta

<

>函数名: qsort 
功能: 使用快速排序例程进行排序
用法: void qsort(void *base, int nelem, int width, int (*fcmp)());
程序例: 
<

>#include <STDIO.H>
#include <STDLIB.H>
#include <STRING.H>
<

>int sort_function( const void *a, const void *b); 
<

>char list[5][4] = { "cat", "car", "cab", "cap", "can" };

<

>int main(void)
{
int x; 
<

>qsort((void *)list, 5, sizeof(list[0]), sort_function);
for (x = 0; x < 5; x++)
printf("%s\n", list[x]);
return 0;
} 
<

>int sort_function( const void *a, const void *b)
{
return( strcmp(a,b) );
} 



<

>函数名: qsort 
功能: 使用快速排序例程进行排序
用法: void qsort(void *base, int nelem, int width, int (*fcmp)());
程序例: 
<

>#include <STDIO.H>
#include <STDLIB.H>
#include <STRING.H>
<

>int sort_function( const void *a, const void *b); 
<

>char list[5][4] = { "cat", "car", "cab", "cap", "can" };

<

>int main(void)
{
int x; 
<

>qsort((void *)list, 5, sizeof(list[0]), sort_function);
for (x = 0; x < 5; x++)
printf("%s\n", list[x]);
return 0;
} 
<

>int sort_function( const void *a, const void *b)
{
return( strcmp(a,b) );
}
<

>


<

>函数名: raise 
功能: 向正在执行的程序发送一个信号
用法: int raise(int sig);
程序例: 
<

>#include <SIGNAL.H>
<

>int main(void)
{
int a, b; 
<

>a = 10;
b = 0;
if (b == 0)
/* preempt divide by zero error */
raise(SIGFPE);
a = a / b;
return 0;
}


<

>函数名: rand 
功能: 随机数发生器
用法: void rand(void);
程序例: 
<

>#include <STDLIB.H>
#include <STDIO.H>
<

>int main(void)
{
int i; 
<

>printf("Ten random numbers from 0 to 99\n\n");
for(i=0; i<10; i++)
printf("%d\n", rand() % 100);
return 0;
}


<

>函数名: randbrd 
功能: 随机块读
用法: int randbrd(struct fcb *fcbptr, int reccnt);
程序例: 
<

>#include <

ROCESS.H>
#include <STRING.H>
#include <STDIO.H>
#include <DOS.H>
<

>int main(void)
{
char far *save_dta;
char line[80], buffer[256];
struct fcb blk;
int i, result; 
<

>/* get user input file name for dta */
printf("Enter drive and file name (no path - i.e. a:file.dat)\n");
gets(line); 
<

>/* put file name in fcb */
if (!parsfnm(line, &blk, 1))
{
printf("Error in call to parsfnm\n");
exit(1);
}
printf("Drive #%d File: %s\n\n", blk.fcb_drive, blk.fcb_name); 
<

>/* open file with DOS FCB open file */
bdosptr(0x0F, &blk, 0); 
/* save old dta, and set new one */
save_dta = getdta();
setdta(buffer); 
/* set up info for the new dta */
blk.fcb_recsize = 128;
blk.fcb_random = 0L;
result = randbrd(&blk, 1); 
/* check results from randbrd */
if (!result)
printf("Read OK\n\n");
else
{
perror("Error during read");
exit(1);
} 
/* read in data from the new dta */
printf("The first 128 characters are:\n");
for (i=0; i<128; i++)
putchar(buffer); 
; z1 [3 }$ N8 c/ `/* restore previous dta */ * v; i" D& y |) q) G; j! |8 @7 t
setdta(save_dta); # p. f/ w& ~. }* @7 K8 M7 U
return 0;
% I+ r% N2 W2 E( g) [/ ^} . \: ]/ l; q$ {( `8 }

9 H$ I6 Z& W: o- d3 l% `6 n函数名: randbwr 
9 x% p0 s, N( z! I功能: 随机块写 8 w! O" ~# L, _# F! g: e
用法: int randbwr(struct fcp *fcbptr, int reccnt); 9 f+ Z* u% i' \- f! v
程序例: ! w1 p* Q! z" Q
#include <PROCESS.H>
* x: X* g! C) r+ g G#include <STRING.H>
: X8 k7 f; M; W# i) A( a! u. ~1 M k#include <STDIO.H>' X }0 W) M/ N0 j* U) q
#include <DOS.H>
: V$ ?; s' Q% qint main(void) Y- i; Y' {# ]
{ ; K0 |: F, j4 p/ r0 H
char far *save_dta;
( m: I% Q8 D6 O+ y4 b5 R9 nchar line[80]; 6 K: }9 L4 }/ ~0 M/ N2 F0 r+ I
char buffer[256] = "RANDBWR test!";
4 F" e: c3 B e }6 ?3 P0 _% ]struct fcb blk; , D! E+ ]& v; z
int result; ( V: Z+ @1 }% U
/* get new file name from user */
' O( T7 }, Z/ K- D: n! M9 kprintf("Enter a file name to create (no path - ie. a:file.dat\n");
3 I8 C/ {2 U3 J& [8 R$ C& u" U' h/ bgets(line); 
; o2 X8 |7 j( T. X/* parse the new file name to the dta */ 5 g. Y7 C: [5 w9 v- [$ Y7 p
parsfnm(line,&blk,1);
; R& i3 }$ E8 h. U. h2 m, cprintf("Drive #%d File: %s\n", blk.fcb_drive, blk.fcb_name); 
2 I/ k# i$ ~1 E6 V+ n+ Y/* request DOS services to create file */
+ @0 Z8 R& T" \if (bdosptr(0x16, &blk, 0) == -1)
' f$ l0 r1 [7 z2 w+ X: p/ ?0 A{
) ^! u* S j0 w4 jperror("Error creating file");
8 s$ a/ X" ~& V6 hexit(1); : s* }* U k+ H4 T
} 
) @* l7 W; P+ p) l5 P) B0 K/* save old dta and set new dta */ ' r: V, N: A( v
save_dta = getdta(); ; t1 _' q6 v* u4 ]4 C4 f r0 n
setdta(buffer); 
1 ?8 |& R, J$ t- _2 }/ E/* write new records */
0 w9 X+ y" ?, \/ W6 ?1 Y$ bblk.fcb_recsize = 256;
1 o) N' {/ W0 H: A6 M! R2 bblk.fcb_random = 0L;
+ J7 t. i3 A, L" b- }# m _result = randbwr(&blk, 1); + x3 s3 o: ` w. d
if (!result) . B E7 t; t" |7 F% D3 x) ?1 ]
printf("Write OK\n"); 4 V4 X* u: z5 B9 K% D6 u
else
6 L0 L- i# E# @$ X6 }{ " \! U3 v& [7 @! N- h0 h+ G
perror("Disk error"); 4 [1 S' T& @6 j% {. Y, R) X/ [
exit(1);
" `- A% a6 }1 P4 B, H4 Q} + v$ N, g8 u3 R, Q9 c' @1 T. ]
/* request DOS services to close the file */
2 s# A3 M4 @1 pif (bdosptr(0x10, &blk, 0) == -1) , ?3 A2 [0 J! h) }# l/ _
{
0 V5 i) o2 c+ o' ^( F2 {perror("Error closing file");
) r9 I; I- E4 H' _# Dexit(1);
7 w% @7 E& S* a* e) O} 
% |! n8 e# S; P. [4 h& U/* reset the old dta */ 4 D0 _2 v" L d. |& r3 ~! Q
setdta(save_dta); F! p) g8 z& _! t9 |/ ]2 J
return 0; % p5 @; l0 w" `" p8 t. u! p
}
& {& m4 r& `" k3 F$ a* P' ~
1 m8 [6 ~: [5 v# r8 x) F, A: g8 [8 f' T: E7 q! J
函数名: random 
* Y3 W' V# B/ Z! d功能: 随机数发生器
+ W0 c- t8 q6 N1 |) R3 e! I$ y7 M用法: int random(int num); 9 s$ l/ u2 y% G
程序例: 
1 E# _. @6 B$ `8 i#include <STDLIB.H>
0 S; H/ q6 I$ v/ ~! s: A7 f#include <STDIO.H>3 h+ z1 |+ o& u* }$ j
#include <TIME.H>
1 v9 s8 Q/ @6 }) @7 Q7 [' _/* prints a random number in the range 0 to 99 */ ; ~6 G* K1 G3 P* I9 }1 V- H
int main(void)
 ?+ Z5 y) d" c8 c1 `2 ~2 c" q6 i{
; [: _6 k1 v5 x, G' srandomize(); & P$ t6 U' l+ g* k4 |
printf("Random number in the 0-99 range: %d\n", random (100)); 6 M' P3 l" E3 z, L7 J
return 0;
$ Y2 ` l5 l9 j* {, p} $ b6 F/ N5 v3 O% R: R

! }+ P- ~) j" u8 D9 S6 ?( ~# w: L/ z5 ?% u/ R6 ?
函数名: randomize 
8 b. W: O0 A8 t功能: 初始化随机数发生器
5 m5 |& L: C* s( l用法: void randomize(void);
) D1 a6 d7 u- {, G( B程序例: . x+ c) i. C9 G+ R9 ~! D% p7 x
#include <STDLIB.H>
" i* L- `0 |- s: I& A#include <STDIO.H># R7 o, B0 n! m/ K% }7 D
#include <TIME.H>
# \9 Q, Q3 w! |! ]% G8 qint main(void)
) g# P9 \, X: i) b- `/ E- r{
. j* D7 W) s# J5 o- E2 z$ _int i; 
 |" e7 }( p- e |- ~2 o. Prandomize();
4 z" x% f: W) }3 H. kprintf("Ten random numbers from 0 to 99\n\n");
+ g0 K, B0 A0 U* M" K! gfor(i=0; i<10; i++)
' j% R+ }# U' W+ d- z3 D! g; yprintf("%d\n", rand() % 100); 3 N/ Z' [% ~, q
return 0;
: {2 n5 [: F0 Y" H} 6 K/ E: Z/ {- l& J6 m4 A; J
9 e* M; S9 D# k& `3 G) g6 F, A
$ J$ U) E7 S+ z" v# u# c6 o4 }
函数名: read , x+ c" d3 f% t3 V/ @
功能: 从文件中读
4 ?" A' d* E5 w2 T/ t用法: int read(int handle, void *buf, int nbyte); ! r. G, o" y9 Q( C
程序例: 
" A; p5 E# n: X7 l#include <STDIO.H>
7 O$ ], a, y1 Y3 a#include <IO.H> U' A3 }+ M' o2 m
#include <ALLOC.H>
5 \0 v: H+ ~; A: K1 I#include <FCNTL.H>
2 F) m" z+ K+ i3 _' b" j+ T#include <PROCESS.H># [" t/ I* I7 R% u/ Y0 H4 X
#include <SYS\STAT.H>& i, X/ V. G4 Y4 N9 j) v1 S
int main(void)
3 }8 i$ s5 r& e" Z% ]{
4 Z" r C% t% M. I% y% Ovoid *buf; B/ r( k! u; Q* U
int handle, bytes; ' Q( g8 L8 \9 D0 U% t* t# a, n
buf = malloc(10); , f2 x) V1 u+ N- [, N
/*
, Z) \9 _# K" f' pLooks for a file in the current directory named TEST.$$$ and attempts
 D; N% f6 l) E0 Y8 fto read 10 bytes from it. To use this example you should create the + z3 h* D4 I* x( o( J+ m# m
file TEST.$$$
, O9 K( h1 g8 m& \*/
 K+ O4 h% w: {+ Z$ g" ]if ((handle =
, ^3 p! M2 k/ p2 D/ Fopen("TEST.$$$", O_RDONLY | O_BINARY, S_IWRITE | S_IREAD)) == -1) 7 f" H, f2 x$ C
{ ( A# Q/ s( f) J, x. e+ Y! D |
printf("Error Opening File\n"); / [3 P" u! [- I( ^5 x
exit(1); # d; u$ g& R# X
} 0 I1 {0 z X+ X( F
if ((bytes = read(handle, buf, 10)) == -1) {
# t- q9 i+ M; B( m0 `1 X) B" tprintf("Read Failed.\n");
3 ?& V) ]5 u* _$ ]' Q qexit(1); 9 U6 h! L6 Y, o
}
: P+ r$ N& J9 Helse { 6 v$ R# ^1 e8 f/ f( B
printf("Read: %d bytes read.\n", bytes); & w( }* W e4 c) t( [; I I' Y5 U
} * N3 h0 P6 t: J* C5 ]
return 0;
! W, W/ o! |- N' f: E- C3 H8 E} 
4 M5 X/ I! t. F0 b' {$ i: j3 Y1 x: A
% W' l$ U/ O2 Z
 e3 f5 j1 l* m+ }" E9 x; G: x函数名: realloc 7 ]1 ?* q0 I* e: h4 B& n& g
功能: 重新分配主存
) [6 j4 x+ j6 @' Q% q; Y$ g0 P# c d用法: void *realloc(void *ptr, unsigned newsize); 5 r3 H/ n7 v; z. n2 j
程序例: * a# C9 |- i2 o5 }
#include <STDIO.H>
& |, ~! \( Y+ K9 e. R/ |" \#include <ALLOC.H>
5 |6 t" Q" T% `( V; B# p#include <STRING.H>2 W- G1 P$ V, ^6 }3 d
int main(void)
% q+ _3 _2 V1 b; n{
# s) \; `+ Y5 y% f2 hchar *str; 
+ i' y3 J* n) T5 j' \2 U. m: v/* allocate memory for string */
" B1 S5 R9 K: ^) L, ]/ h8 Jstr = malloc(10); 
3 ~6 k% P' t7 B5 f/* copy "Hello" into string */ 4 l: f$ q8 i% i% U8 T+ u$ O
strcpy(str, "Hello"); . q7 q+ C7 R+ o
printf("String is %s\n Address is %p\n", str, str);
5 p2 {/ y0 w, U7 Xstr = realloc(str, 20); 2 J2 p7 n+ k) r. p5 l+ B+ k$ g; U
printf("String is %s\n New address is %p\n", str, str); 6 C! P/ w; P9 u( y
/* free memory */
% z# `+ y8 g# ^3 o7 R: W+ r# _free(str); ' Z. K# F+ q8 y" B3 v( A/ r
return 0;
8 L! u0 d; h2 O+ Y5 C7 N; }4 Y- I}
! i6 y; c" A6 P$ M2 D- B5 x& u/ E& n7 s8 ~2 i
& S. o, }7 t5 R/ a7 R% X
函数名: rectangle w" ^$ O E+ ]. Y6 Y
功能: 画一个矩形
0 r& p7 A5 N/ N/ Y( z: L用法: void far rectangle(int left, int top, int right, int bottom);
" u+ f3 p& o Z3 g& C/ \程序例: 8 I9 q5 w+ j' q5 n
#include <GRAPHICS.H>4 H3 `( H! f: }2 P$ b* u% D
#include <STDLIB.H>& b# E; {0 v2 q# p; R3 ~( r n5 i. j; K
#include <STDIO.H>
& }% l. }. Y/ p1 l1 v#include <CONIO.H>
. @; Q. V5 o. E) h2 [7 K1 g Eint main(void)
$ u2 t$ B3 y: e( G# F u{
$ \1 P0 f, b0 {0 V5 G1 v/* request auto detection */ ; |% h1 v$ Z: L2 x; v- U' V$ t; _
int gdriver = DETECT, gmode, errorcode; 4 U5 V) A8 {$ [% x) V! w" e" V! Z5 R$ i
int left, top, right, bottom; 
/ |3 I# { {6 ?9 j+ Y2 Z/* initialize graphics and local variables */
. c/ ~% W8 N% i, W* g/ w$ j0 xinitgraph(&gdriver, &gmode, ""); p( J# {% k/ t3 _
/* read result of initialization */ 4 l4 ]( M, E9 \* Y
errorcode = graphresult();
4 q- i1 w& I! f. L# m# v. i8 B( Kif (errorcode != grOk) /* an error occurred */ 9 T; U' D3 s3 M' H( g& h8 W
{
) |4 u- b( \: D2 bprintf("Graphics error: %s\n", grapherrormsg(errorcode)); ' A: `8 F5 ~5 h
printf("Press any key to halt:");
% R1 j% T" C. k; q; |" ^4 o7 Igetch(); ! O/ V2 r& E* P8 n
exit(1); /* terminate with an error code */
! [1 ]: j8 t' X! ]) B% R0 E} 
: ^+ I& X6 `5 V& M% Vleft = getmaxx() / 2 - 50;
; G, I2 u# D' h% ?( W- ?( g8 N1 ftop = getmaxy() / 2 - 50; 3 `1 Z! Q) ~' \; x/ \
right = getmaxx() / 2 + 50;
( a" a5 [( K+ B- L- z$ v3 }bottom = getmaxy() / 2 + 50; ) W+ B) ?0 ~% i* n% ]+ K
/* draw a rectangle */ C$ Q3 N- O3 j
rectangle(left,top,right,bottom); & F, x1 B# {" L% m @. N
/* clean up */
5 P: J- F: t% N1 T9 ygetch(); % s9 c* p. ^/ @' \
closegraph();
8 O; Y6 w) R. i1 ]6 Lreturn 0; 5 z7 @! w. t1 x" u& h
}
8 Q0 W: F0 v* C! X# m' n; E) O1 Z& U: R- T8 c' S- B D

/ S8 V$ P$ i. u5 k函数名: registerbgidriver 
( b L8 x; e# ?+ b功能: 登录已连接进来的图形驱动程序代码 0 G% x8 j3 F' u# A4 x. i- n B0 ?7 W
用法: int registerbgidriver(void(*driver)(void));
* \/ h/ z1 }) |' K8 G+ M1 ]程序例: ' Y( m7 y! S8 T2 n
#include <GRAPHICS.H>
0 m1 N; _- y6 Q( n8 s8 u#include <STDLIB.H>: E! `: @8 E2 v' B* v
#include <STDIO.H>
1 X- b* r0 a/ W- B: R( n0 N* L#include <CONIO.H>. H6 t& A3 M7 s2 D) L l0 E
int main(void) - T/ p* @+ [2 k1 w* h
{
8 e. o5 f$ N5 I' q9 K/* request auto detection */ % w; u. u- [: s3 e/ B S" p$ a
int gdriver = DETECT, gmode, errorcode; 
& G( N, u$ Z% w* k; Q4 H+ r* j/* register a driver that was added into graphics.lib */ & P: M/ G B9 Z" N* M. i
errorcode = registerbgidriver(EGAVGA_driver); 5 n- k5 n# M" k: w& S
/* report any registration errors */ & o1 ` G! }" R8 z" f7 _$ b* t( E
if (errorcode < 0)
% o+ U+ G/ ~' s4 _- M" @$ X, L{ 7 U, {& D* `! F; N3 w8 [
printf("Graphics error: %s\n", grapherrormsg(errorcode));
7 J5 t K, r t pprintf("Press any key to halt:");
, p" x- i% ~4 L- M3 p6 u, ~getch(); 3 k3 c. `" @: X; T
exit(1); /* terminate with an error code */ 7 q0 m0 x" W. C5 `
} , ~6 c5 S! O; ~7 P7 F1 C
/* initialize graphics and local variables */
; C, w" @+ K& _2 Rinitgraph(&gdriver, &gmode, ""); 
' I5 ?* u. d' `0 e- t$ A/* read result of initialization */ ( v3 y8 a0 C5 l
errorcode = graphresult();
. n& ]! J# |- ?/ r8 ?if (errorcode != grOk) /* an error occurred */ # m& s: U7 y. e' [6 x& A
{
+ D6 J& o" [& g8 Z+ vprintf("Graphics error: %s\n", grapherrormsg(errorcode)); + f: J2 v' s' K( }, c1 M7 M* W
printf("Press any key to halt:"); , Q5 U3 b( u l0 I& U" e7 g
getch();
1 j3 W) i o: z" h( `exit(1); /* terminate with an error code */
4 n3 |7 N. P8 J' J5 a} + d2 G- R' |1 H/ s
/* draw a line */ ( g9 v6 Z8 {2 p
line(0, 0, getmaxx(), getmaxy()); ) i# p0 |5 Q2 {. X
/* clean up */ / Q- J8 j Z. X
getch();
: b$ X5 [! Y! H/ E6 H1 ~6 a( s+ wclosegraph(); $ `: N+ N$ Q+ n+ e
return 0; 3 Q, K& d& ?) H& _0 K; D0 O
}
$ r( o6 Z! T! ?" {; x. c
; r( }/ D" }' Y3 q* F; ^9 U$ `/ D, f1 ^
函数名: remove ! V( ]3 q' x3 I% L- Q% u6 f
功能: 删除一个文件
; h4 r6 p" M' y% Q+ i: X4 _用法: int remove(char *filename);
! |4 d' N( O: H5 v3 V程序例: 0 f$ X1 Q7 o' q9 s* h
#include <STDIO.H>
9 F8 P. @, i d4 i2 mint main(void)
9 i( k3 d, u: m5 w{ 3 h8 P7 j1 {7 H# ]" ^3 h
char file[80]; " |4 o/ N+ @+ S% F, d, D2 J
/* prompt for file name to delete */
4 J# p" {, D2 l% \0 g: e3 p* Eprintf("File to delete: ");
, _1 ]2 o6 ^. E/ R g. Tgets(file); * U6 C, A. {3 R) [( b
/* delete the file */
% e n1 j; N" R( ]if (remove(file) == 0)
1 L7 ]/ U8 l3 h- gprintf("Removed %s.\n",file); 2 g$ g; w& i; Q+ e
else
) |3 O: L8 a7 t: D1 ]5 D. ^perror("remove"); 2 w4 j# D9 T* N3 M S
return 0;
$ E$ N& o8 S" e4 a* x4 X} ( Z. P2 X( D6 `" G# F* r) W% m0 K
2 f8 d' x% o" `0 n
% h7 E4 x2 U$ g/ d$ U5 F9 i9 u' u/ O
函数名: rename 
4 N9 y3 W0 U# J E3 n; L+ g. \功能: 重命名文件 6 m, Q) b+ k9 Y+ ]. O
用法: int rename(char *oldname, char *newname); & h7 N( g4 W! |% o7 q p
程序例: 
7 L$ a1 E5 {0 F5 c& f) T9 |#include <STDIO.H>9 O/ b% k. e e u' y( m8 H" s
int main(void)
$ }/ B$ j6 D" n+ t$ n{ : u# q0 x W5 v* o
char oldname[80], newname[80]; 
- E! [7 @3 }) O1 X# V: l/* prompt for file to rename and new name */ 6 |1 Z# B- V3 V' j. T6 C8 l
printf("File to rename: ");
* N. ~$ `# P ngets(oldname); 3 K, d% C6 I7 u
printf("New name: ");
$ s9 N; \" |& i2 H: O+ j& `8 v/ [gets(newname); 4 |: ]# P! J3 x/ R: g0 y
/* Rename the file */
6 g' m1 K3 I" W5 {8 bif (rename(oldname, newname) == 0) ) v+ m/ S% Q3 _' g$ V% @) R
printf("Renamed %s to %s.\n", oldname, newname); ) w7 C& {( \4 v% k, \. k( E
else
9 Y) O: ]# s2 }' aperror("rename"); 0 p; \7 b6 x& I* X: j1 I
return 0; 6 i. ^1 B) _6 U
} / U8 f) S( |( E
8 Q6 ?7 _1 t: c0 M4 Z9 o# Y
8 J& B. ^& r/ ~8 N
函数名: restorecrtmode 
8 S- ^3 Z/ P/ Q4 A5 d: A功能: 将屏幕模式恢复为先前的imitgraph设置 8 y& b6 L. d' Y2 c2 D5 T
用法: void far restorecrtmode(void); : ]; [3 i( x. `* K
程序例: $ l0 v, B2 F/ q6 `. d
#include <GRAPHICS.H>
 u! h4 d2 d2 M9 k6 ^1 C" J#include <STDLIB.H>4 G: }5 G% v" b+ K: c; E
#include <STDIO.H>! j6 C+ h+ {7 N. A6 {! I
#include <CONIO.H>
; o$ y5 X' y# K( m9 s& _7 Jint main(void) * _1 n% C( s% C. b, H- t* d$ B `1 s; n
{
0 Y# |4 s$ ^0 e5 Q/* request auto detection */ " W$ {3 Q# ?2 H. `6 D/ z1 b! Z$ C
int gdriver = DETECT, gmode, errorcode;
int x, y; * B: _4 |/ U, L3 E0 j- K9 S
/* initialize graphics and local variables */ ( n: G/ R' S; N
initgraph(&gdriver, &gmode, ""); 
/ K R3 n# X" y& [$ R n+ [/* read result of initialization */
& z# w8 e) p3 s' Q# h" B7 l6 Terrorcode = graphresult();
# B; `0 e3 T9 I1 p0 |& ]4 Uif (errorcode != grOk) /* an error occurred */
8 h: Y1 I) W' k. p{
9 y! ]7 q2 k5 R4 n# b% { Vprintf("Graphics error: %s\n", grapherrormsg(errorcode));
8 f" E! l- z* Q' C1 Xprintf("Press any key to halt:");
4 p& ^5 }/ d+ }9 Q% p5 ]getch();
( h! `2 M/ d1 [8 O5 l/ A! m4 Uexit(1); /* terminate with an error code */
, ?- M6 R' j0 K/ Z: G! A} 4 c# E1 Q, G3 T9 s5 e& i
x = getmaxx() / 2;
$ v' Q/ l2 [; B) ?9 Cy = getmaxy() / 2; ! \! ^: C* i1 a7 v9 p" s( F/ W7 P
/* output a message */
0 [3 t5 g) i( _! f! Ysettextjustify(CENTER_TEXT, CENTER_TEXT);
3 s" e7 Y Q2 X& d9 S4 d; _& C% Youttextxy(x, y, "Press any key to exit graphics:"); , w+ k) V5 u/ ~
getch(); 
1 X$ H" M6 }0 r& A; d& }! t/* restore system to text mode */ * R* E. l) c) S) F7 q6 @
restorecrtmode();
7 L$ ^% v2 A" K7 R/ Uprintf("We're now in text mode.\n"); ; e$ K$ G5 \$ }& p
printf("Press any key to return to graphics mode:"); J, j( P: Z3 i; \2 c
getch(); 
7 d* t$ N* h6 d3 D/* return to graphics mode */ ! V c4 t S2 w( {: N3 \# k) R" W
setgraphmode(getgraphmode()); 
- _3 P; ^! K6 K/* output a message */
2 }0 T$ j2 q2 ?" U+ Q2 k* Ysettextjustify(CENTER_TEXT, CENTER_TEXT);
, z. @" i" N3 ]6 }) q( b; souttextxy(x, y, "We're back in graphics mode."); ' E- S) b, j b3 a: J$ `& T& }
outtextxy(x, y+textheight("W"), "Press any key to halt:"); ' t' B$ q: D/ k# H# [. z4 s) S
/* clean up */
5 M" U. L, c4 O Jgetch(); 2 m; ^ s5 F9 h) ]! d
closegraph();
8 l' d1 m; v! f7 ~! O! \# ]0 Ureturn 0; 9 c: b5 e. _0 s+ ]( }; M6 k: W
}
0 I/ [' c& |& d* }3 f
) E7 o# z2 M% x5 x/ d% z! ?9 P; w5 C8 p5 ] N" J% }
函数名: rewind 7 D8 t! T+ {/ B0 ?; ?
功能: 将文件指针重新指向一个流的开头
/ s; m, m( N2 x; }2 \8 ^- w用法: int rewind(FILE *stream); & c- F. R. @5 a" H3 s
程序例: ( r6 u k" d) z" u( z7 z2 [* k. O
#include <STDIO.H> R3 S8 x" ^' b' z: g3 }3 N
#include <DIR.H>1 p x* y) y1 V7 j t5 O* a
int main(void)
! \ N4 |5 B) A. E{ # J4 m+ @9 E ~# N" }
FILE *fp;
, L& f! T! f# L' nchar *fname = "TXXXXXX", *newname, first; 
8 L8 s( G4 {/ e" f7 x: Knewname = mktemp(fname);
! ]/ v, `/ c4 U4 I. Xfp = fopen(newname,"w+"); " J, O9 {; T' n7 d
fprintf(fp,"abcdefghijklmnopqrstuvwxyz");
5 _% I1 ]# n! L, y) irewind(fp);
; R$ u+ x C( C4 `5 X7 [fscanf(fp,"%c",&first);
% V1 R' x9 e) b/ L! xprintf("The first character is: %c\n",first);
: h1 y; L8 D }; z+ ?fclose(fp); Z% L3 e3 m9 |' t) N, |/ N; t
remove(newname); 2 }- L- U4 C+ c+ O0 B: H3 A+ Q
return 0; 3 k3 E9 d" d5 W' Z T3 o% i" B, z
}
& r9 [: L/ c0 \+ j; D5 y
- b7 a! @$ {/ ~- B& x
/ k. t. {; X! y7 t9 z. B# N函数名: rmdir 
* A( W i' f; L% j9 H% c功能: 删除DOS文件目录 ' g+ n% O8 B& f6 Q: ~
用法: int rmdir(char *stream); 3 P2 R0 o. k T' a* T
程序例: # Z7 H; J5 b: S7 L: _0 A( x, L: T
#include <STDIO.H>
; c8 V4 T& V. L! _3 B5 k#include <CONIO.H>
& D$ u' O' P* ]% \% c9 u* E6 H#include <PROCESS.H>' x: ^& d" J% e N' }
#include <DIR.H>' d' X1 J, a" O- q& o5 h
#define DIRNAME "testdir.$$$" 
% B( Q: i+ z6 Y; g9 Xint main(void) 4 x: D$ f o( }/ N4 n0 b
{ ) P/ k+ h$ ?: b' O _
int stat; 0 w9 c( N$ K5 A1 ^# B5 W. n) _: i
stat = mkdir(DIRNAME);
0 Y8 z+ Z2 i6 Lif (!stat) 8 z. z* E' k* u
printf("Directory created\n"); 6 M- E: ~/ a8 ?5 V! f; `
else ( w9 a, F8 m5 @0 b
{ - Z2 ~& S" A! s( ?+ `
printf("Unable to create directory\n");
' G; C. @% W- ~' H- N2 ~$ i9 iexit(1); / J% e* M2 e/ K/ H1 b" u
} 
/ P7 E/ J, Z9 y7 A( g7 k% Cgetch(); # \7 n9 ~1 z. h( L
system("dir/p"); 9 \6 K2 B7 i, u9 G; p% h3 v+ j
getch(); & \& ~! N3 ~. z1 ?( u
stat = rmdir(DIRNAME); & g9 J5 |3 _+ I/ _8 Z
if (!stat)
9 ?& u1 r7 Y$ o$ {; kprintf("\nDirectory deleted\n");
% }- m& ^' F& F0 kelse
) F( F2 S; w7 H9 a. k! B$ g+ _) ?{
" ]) t: w" U9 o2 h3 G1 Sperror("\nUnable to delete directory\n");
; l+ ~8 z5 D: z5 v8 ]+ Eexit(1); ' y5 a2 I( x8 C) d2 h! M
} 
; R8 |; u: y O* E+ W$ J5 D) xreturn 0;
. E$ _( x9 B& i}