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函数大全(q,r开头)

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发表于 2004-10-4 02:55 |只看该作者 |倒序浏览

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<

>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); 1 Y8 I) e/ o! a) s5 U w
/* restore previous dta */ q3 T5 S- Z- }8 j- w* |" x
setdta(save_dta); 
: g% S8 U) `' l$ Ereturn 0;
3 f7 q- Q' g2 _/ P} & e/ N# M4 Y. Z% j E2 S

7 s! b+ Q( J; W/ Y2 H5 V; S函数名: randbwr 
 L9 p2 I7 @4 l2 h$ W6 t功能: 随机块写 v- I; k/ e$ q4 b8 J1 |
用法: int randbwr(struct fcp *fcbptr, int reccnt); 7 u0 n" c& m* t7 h+ B( _
程序例: & f! O) o) _3 T! W; R! e$ }
#include <PROCESS.H>
% [% K" I, f6 S1 `7 X( ?' G2 w#include <STRING.H>
9 F4 ~" h: S8 v: N/ I#include <STDIO.H>
3 h" k/ `1 F. U#include <DOS.H>
5 D B8 y! H, C" D9 \int main(void)
! k; S* O$ ]& S{
" L. h5 u" [& M8 |3 ~char far *save_dta; . I) D: }, w/ Y6 z! ]+ j$ Z
char line[80];
1 y# W, R) @" Z+ Q3 fchar buffer[256] = "RANDBWR test!"; ) \& t. j, v+ p- Q
struct fcb blk; 0 _0 m6 N) F" V, V
int result; 5 X7 K: t2 ?8 E. Z# F+ V8 I
/* get new file name from user */ % o- \, t; d# N6 _# T3 E
printf("Enter a file name to create (no path - ie. a:file.dat\n");
gets(line); 2 w% I/ Q+ D1 H7 b* h
/* parse the new file name to the dta */ ' T: h- l t/ V* x/ n% v
parsfnm(line,&blk,1);
8 A3 H8 M2 ` s$ r7 h% S, dprintf("Drive #%d File: %s\n", blk.fcb_drive, blk.fcb_name); 
6 }6 F* C! h' l& S+ q1 x( G/* request DOS services to create file */ $ @% b8 f* X( K" J8 w
if (bdosptr(0x16, &blk, 0) == -1) $ \- }( u) F( i% c. r' w3 w: A* k
{ : F2 x' Y: L0 f7 u! X$ d
perror("Error creating file"); 1 M6 U) q4 T) U: `9 Y' r* r. G
exit(1);
3 D, Y6 _! S/ y6 M} 
2 P) v( J" h+ s& \/* save old dta and set new dta */
, o2 m- J ]' g$ R6 Ysave_dta = getdta(); 3 J# N q' m* Q( r2 n9 E
setdta(buffer); 
5 b6 _& y/ e+ q/ _2 ?/* write new records */ ! \0 t, A1 ~1 }+ r; C/ y
blk.fcb_recsize = 256;
9 D! V- H! `# [( C) Wblk.fcb_random = 0L; 3 A$ g( v [( I
result = randbwr(&blk, 1); 7 w, y! b- f m
if (!result)
; z8 _! v/ G4 r, b" H8 gprintf("Write OK\n"); - y4 L3 j1 A7 g; j o
else
' J/ A. M& e1 T5 N/ D, ^{ 6 {' @$ ]7 ~, |) a# q1 O4 t: L
perror("Disk error"); , g2 f( U: h" y. ^8 D
exit(1); , j e0 y) f R" b& Z
} ; R* y! L3 B% v
/* request DOS services to close the file */
) ]6 n6 V% {6 F3 R+ dif (bdosptr(0x10, &blk, 0) == -1) . u7 u; ]- I, d( J4 S( [( j/ @# I
{
9 E& p4 {, j7 z" Uperror("Error closing file");
) v* E! M( h( w0 m* h) Sexit(1);
" E. A! X" a$ |0 r} " z8 Q) [! Z& O# |3 r
/* reset the old dta */
. d+ T( |5 C3 S7 V1 u& f7 p1 ?setdta(save_dta); . [+ W- _+ l$ E( W, M5 Z& {
return 0; " r2 a3 M% |( ?. t7 A+ {
} 5 J" T0 I( J, \) u; j, A# M

3 z/ \( M( a$ }- I
& P8 | C0 h' p7 l' J+ }函数名: random - f% Y K9 y$ S( ~8 u& Q( i" N7 [
功能: 随机数发生器 7 p1 d0 c, m7 G% @8 p
用法: int random(int num);
- M" G% h7 k4 r9 h) S, }程序例: 6 O. W/ |2 v; W! ]( @0 M3 ~
#include <STDLIB.H>
#include <STDIO.H>' d: x- B& r- J8 {! _! L
#include <TIME.H>
) m( M' K, B( r/* prints a random number in the range 0 to 99 */
1 h( \7 [8 d/ o1 d- iint main(void) $ e$ o. v; k# M% _' l' l! n+ ?* r
{
3 y, S2 ?% R, J- A. Zrandomize();
7 y0 W4 n' f' @printf("Random number in the 0-99 range: %d\n", random (100));
7 _% Y, |- O7 b7 K! ^return 0; % h6 q O# {% \0 V2 d0 x/ |
} 5 D. i( q( Y# o' x. g; n2 k

) o8 z# J5 l) a1 d& U
, y7 l+ Y) x: C# F函数名: randomize 
- Q( d. ^7 W1 `. b* o9 e. j4 _! n功能: 初始化随机数发生器 / f+ l# _4 i/ }% A; N$ i& A* a
用法: void randomize(void); + B2 t+ D6 \$ A
程序例: 
* `6 V% b* {& F3 S4 j' ~#include <STDLIB.H>
/ Y3 H- Q* f9 H$ N" E$ b! z1 ~#include <STDIO.H>1 Q) W- m1 H: F w% a! t# C& z
#include <TIME.H>8 H* z' V0 S R; j
int main(void) 7 u1 [ ^' Y/ w! Q- z5 @# q
{
$ P; y8 ?3 K* lint i; , @9 G9 w0 ]5 {6 N, I/ u$ [* r
randomize();
" D% ~0 f( O8 D, ^: Y5 I7 Qprintf("Ten random numbers from 0 to 99\n\n"); 2 c; M3 P2 o3 F$ d
for(i=0; i<10; i++)
; S! a) i; i$ i( Kprintf("%d\n", rand() % 100);
2 u8 A4 L% N, }- K$ i! p% Xreturn 0;
# w7 N4 c' O- q' \- P7 x} ! M: K( [5 x0 ^4 W: A+ S

: e' F- G8 h* i/ P' ~0 U% ^
5 D, G/ N! B! g$ X函数名: read 
9 M- d* C0 _+ p& [6 G. v5 L功能: 从文件中读
- y5 P: w7 b7 a/ a' F' I用法: int read(int handle, void *buf, int nbyte);
2 k( i2 e. ]# m程序例: 
% l6 O4 }& P2 i! w#include <STDIO.H>
" h% U: W+ Z% z' W1 W A0 c' l#include <IO.H>$ h8 M9 s( D( }' }4 \
#include <ALLOC.H>
3 G6 d- T3 A6 O- Y3 @" M#include <FCNTL.H>
; `$ B4 e' j3 [# F& h% y5 Y#include <PROCESS.H>
7 {& \. d1 ~7 N; J% h#include <SYS\STAT.H># M) o, b+ r/ \6 [8 V
int main(void)
# p5 }3 k2 Z' L9 e{ 6 M* j6 B9 X: d& U
void *buf; & d$ A$ f( [5 m2 s" C3 G8 i
int handle, bytes; , m4 a7 M# ]3 o6 L4 _2 S
buf = malloc(10); 
1 y/ o' d# n' s' W/* ! h, t/ F8 K4 R& V9 O
Looks for a file in the current directory named TEST.$$$ and attempts + |* {- z" W/ Z$ l$ z. ]
to read 10 bytes from it. To use this example you should create the ) Q( b: ~, J8 ?4 f' h( L
file TEST.$$$
, {1 U# Y" J9 N5 {, n( h" M*/
' d6 M8 z" s$ [, N. W0 sif ((handle = / A( Z" b# L. ^/ Z/ y/ r
open("TEST.$$$", O_RDONLY | O_BINARY, S_IWRITE | S_IREAD)) == -1) 5 G$ M7 [7 b# ^* @& o
{
' C* w7 {: @/ Q6 [( ^& P' E: Jprintf("Error Opening File\n"); 9 z2 I, e$ O, p" j* U" ^
exit(1); 0 A) e0 }0 `; h0 ~
} 
7 g. w: x0 e! p/ v7 {1 f tif ((bytes = read(handle, buf, 10)) == -1) {
0 O; {$ F% J1 ?" ?4 S( ~( Sprintf("Read Failed.\n");
9 P6 j) V: p. qexit(1); 7 s& ^: o1 o# f0 U) L. d
} " _) G3 n- p5 l. p Z, j
else {
8 Q2 i# j+ A3 [3 O( u" Rprintf("Read: %d bytes read.\n", bytes);
6 U: R* X4 r8 P3 p$ L}
% j7 e& L7 A; `0 P+ xreturn 0; + @% E4 w g @$ X, F+ m4 R
} 
- ?8 i" N3 e+ E0 {- j5 W0 i6 ?+ Y1 m; g6 B' a7 ]& p% Q

8 Z. u9 d0 v3 o, T" V' |/ s4 U1 _函数名: realloc 
; t1 h- ]% |& X4 j% q功能: 重新分配主存
 S. B; l. Z4 {* l9 a; U1 f用法: void *realloc(void *ptr, unsigned newsize);
5 E) c! j D; X程序例: 6 [; h* o% C, j4 V
#include <STDIO.H>
- y( X# l3 F5 G% l0 x' v#include <ALLOC.H>
# [, |: i# u' t$ b6 R# r* O#include <STRING.H>8 S% }* y/ q: ^3 b
int main(void) ! K- K+ j' U$ e8 c
{ 5 @7 A' S5 {" D9 L1 \' ~' k
char *str; 2 \; g) ~* S+ j
/* allocate memory for string */
' h) ]: u. @' U/ [% Z, }str = malloc(10); 
* E( c6 i9 R- x3 z6 q/* copy "Hello" into string */ 3 V t" f: k1 x0 T" h
strcpy(str, "Hello"); 
' h& A8 }2 }/ `: V! r5 j" v( Bprintf("String is %s\n Address is %p\n", str, str); , \! ?% z1 m5 A+ h T
str = realloc(str, 20);
( Q \2 d) P, yprintf("String is %s\n New address is %p\n", str, str); 
1 h0 X% |. A4 U @+ i& W/* free memory */
4 S/ D9 ^: @; T$ j) V8 Gfree(str); 4 n6 P+ |( v D% {+ }
return 0; : K2 b! c* n* B% o! F1 o
}
( G7 F5 Y, J6 v8 F' k1 M- L/ z; H% c; [, {8 W ]
9 e: O7 p; E8 c* Z1 t' a
函数名: rectangle 1 Z- b9 H) _$ R# N8 z: m' k
功能: 画一个矩形
: B+ v8 m3 t, r2 @; O用法: void far rectangle(int left, int top, int right, int bottom);
 q0 S5 r9 M; s3 V3 m程序例: 4 O( O* I- J* t# `
#include <GRAPHICS.H> K# s3 d& }; _5 h. |8 y: Y4 g
#include <STDLIB.H>
$ V& K9 v. i* Z) t5 a#include <STDIO.H>* j! b) j' Z# S' o; x4 v
#include <CONIO.H>2 G* q4 r( Y$ |2 Q
int main(void) 9 B' Y* p1 U& {6 `
{ 5 x* C% w8 d: x; s* }2 F6 w3 d
/* request auto detection */ / R6 k d( w# c6 _) ~$ z8 S
int gdriver = DETECT, gmode, errorcode;
! N. d8 H/ |: E+ O Kint left, top, right, bottom; " o, ^0 [) s6 W9 i
/* initialize graphics and local variables */ 6 ^; { p- _1 D6 R
initgraph(&gdriver, &gmode, ""); # r6 d( u& Q9 B! R
/* read result of initialization */ 0 T$ P) U, n1 p' x/ n5 j; \
errorcode = graphresult(); 3 m k$ M# [4 z0 F) z3 X+ ^ H* U
if (errorcode != grOk) /* an error occurred */
+ R- l: D: c) o{ , a) S' X3 U& K& \& d# Q0 L
printf("Graphics error: %s\n", grapherrormsg(errorcode)); S n9 e& z0 h& R+ L
printf("Press any key to halt:");
+ U9 n+ D/ |* c2 V+ v' N, kgetch();
: u6 w3 b: ]3 J' M @: V J3 @exit(1); /* terminate with an error code */
% j# E2 F A8 Z2 X3 z ^} 
 Y2 g4 ~% r7 sleft = getmaxx() / 2 - 50; % k7 S5 C* Z2 O4 X, Y! B
top = getmaxy() / 2 - 50; 2 [; i4 V. j6 I' x/ c
right = getmaxx() / 2 + 50; 6 ~* ]& k0 P# \+ m' a
bottom = getmaxy() / 2 + 50; 
% d3 J: Q: t& E7 A, H, T1 {1 A/* draw a rectangle */
; M: B* ?0 i7 L4 l/ R+ _rectangle(left,top,right,bottom); * Z" q! b4 @5 T: Z
/* clean up */
* A# q u: m R. ]7 Ogetch(); y" f8 ~' p7 J4 T0 p/ ]
closegraph();
0 p+ W7 j) N& l* h4 C% p8 Y; ^return 0; ' D2 p, F7 q5 a6 [4 v
}
. J7 R' e; A. v) ^7 e0 ]
: b8 ?/ ^# V" {/ H7 p5 U' I+ M: M! H& p& M$ w m
函数名: registerbgidriver 
; }; C6 Y% i; A8 C1 @功能: 登录已连接进来的图形驱动程序代码
: z; C; g/ H9 K' ]. J/ C* `用法: int registerbgidriver(void(*driver)(void)); 5 ] k! v1 v u
程序例: # W# q C; }0 s `: q
#include <GRAPHICS.H>
. j' Z" t1 @4 s. b#include <STDLIB.H>' O5 j, A# n- G) \8 D
#include <STDIO.H>
" o# H: Y& p6 h& c' H#include <CONIO.H>* ?! i* O9 s+ @/ g% ?
int main(void)
5 I& l& t; L3 R" ]: ]0 B2 ^{
" }' Z9 f2 B6 e6 O/ o4 J: i' A/* request auto detection */ % w/ x2 H( U% R6 B* p
int gdriver = DETECT, gmode, errorcode; 
' A5 E' ]' W% i# w$ h% r8 m9 o/* register a driver that was added into graphics.lib */
, a3 D% P" Z8 X2 G. H: werrorcode = registerbgidriver(EGAVGA_driver); 
- m) R3 y" z, h2 x8 S8 c$ T- o/* report any registration errors */
9 X, R' g3 i/ A: c+ R: @if (errorcode < 0) ( P+ h" D. v+ S+ u
{ 7 s$ G9 h) j& X+ O9 z, S; A
printf("Graphics error: %s\n", grapherrormsg(errorcode));
 O+ G9 G; h3 pprintf("Press any key to halt:"); ! X$ b l) v' { y
getch(); # \) \1 D z! h% m
exit(1); /* terminate with an error code */ % B: r( ~! `+ l# r4 u& a6 b
} 0 |" r2 z0 [$ F# a9 X, K' }
/* initialize graphics and local variables */
: V% m! \" {7 M7 B2 `* ~! j" a4 Qinitgraph(&gdriver, &gmode, ""); 6 W9 p9 h! {0 U7 D2 h8 z& x6 Y
/* read result of initialization */
2 ]! @; i/ y- [" s, e( yerrorcode = graphresult();
& r/ r1 B- l9 O2 ]3 i( u% g; a! hif (errorcode != grOk) /* an error occurred */
2 n2 F/ f+ j: I o. {{ 8 N4 E! j8 c: C% t6 f% e
printf("Graphics error: %s\n", grapherrormsg(errorcode));
, x; V; s7 Z7 `: N7 P8 }# qprintf("Press any key to halt:"); 6 ]( ], A2 M; x, g) R
getch();
& H/ w$ o5 }- O7 I( h6 A% ~exit(1); /* terminate with an error code */
) J' ~, n2 C! `+ H} 
4 |! e8 v- K2 V$ ^! c; B, D6 Q/* draw a line */
1 \! L2 Z. G4 Eline(0, 0, getmaxx(), getmaxy()); 
! R! g, n8 s" J& t o$ e/* clean up */
9 ^1 W' C- [+ z) g9 N, B! u) ^( W; R- xgetch();
+ P+ _; J3 O- b( R+ jclosegraph(); 3 P% F+ }, F4 B( K* O* ]. R
return 0;
* @# G5 A }, w4 `, L} 6 o3 j V9 H1 }; p9 Y

+ m$ J4 z2 b8 S& Q; r. V: S
* q- Q) Q$ H3 p0 ?' ~$ O# P函数名: remove 
0 c4 U7 ?1 ~, s- J& v: |; n功能: 删除一个文件
1 Y g- V; ?) a3 [用法: int remove(char *filename);
% T+ @( p# m# i( \ `, V程序例: % L6 |# I% h5 G) N; [
#include <STDIO.H>
( _% M6 P/ O. K8 ~4 s: Sint main(void)
/ @9 b) _: s# t2 `; |{ ' ?; N4 V( d" y* Y/ g" O* c$ f
char file[80]; 
! [4 Z2 _$ X4 s k/ L/ r/* prompt for file name to delete */
! {6 d5 ?4 [+ M4 K% e! Dprintf("File to delete: "); : f$ i( h( g& t
gets(file); : B# y9 W- G% p2 u; X x9 `( L
/* delete the file */ , G- I2 U# V& d1 n; F `
if (remove(file) == 0) 5 i$ t8 i6 C. ]0 s$ p8 z4 H7 i3 T
printf("Removed %s.\n",file);
0 q. X3 G# m* S3 N0 x" L2 helse
$ z# f" F* S& Z# rperror("remove"); 7 O9 C$ U9 m2 M: C+ l) U/ I
return 0;
7 [3 N" L) T" {( Q/ F" _} 1 B* t2 b, H2 N) f- i1 E
2 O+ w/ A' X/ s
1 E/ J2 b8 w; K7 G
函数名: rename 
2 v+ p2 P: y/ l* A, }功能: 重命名文件 # [; I$ a+ s. k/ f* E
用法: int rename(char *oldname, char *newname); 5 E# ^" L( Q9 c( U4 H
程序例: . r u; H, G% u$ f5 y) y& h! a$ N; T
#include <STDIO.H>
& f/ V; W) P( k/ O$ }int main(void) * s1 U _; l& Q
{
+ n) r+ _4 ]) D0 g" L( \9 g" y3 \( ]char oldname[80], newname[80]; j" a+ u. I/ E. f( i) [9 u7 r( P
/* prompt for file to rename and new name */
. m' R6 S, F4 p2 x. h9 Q4 {* p& x vprintf("File to rename: "); : O3 N O/ f: P. U' o3 V
gets(oldname);
* _/ h) f/ _4 v% [printf("New name: "); F& J+ [1 F k/ U
gets(newname); ( {* U2 J! r0 s' y, q) p
/* Rename the file */
1 E) N! V, K. W& I5 T* x# eif (rename(oldname, newname) == 0) 5 u9 ]. [& Z: ?' g9 a$ z8 { {
printf("Renamed %s to %s.\n", oldname, newname);
( C1 X. n( l9 d$ _8 u% nelse
# n* |1 s. n% G- _perror("rename"); ' [" k8 `: N( @% }/ N% |& U) q
return 0;
' X/ V4 A* u+ v$ r+ B, N+ Z5 S}
) [8 E. ~9 u7 ?- m$ M3 v2 _
) I7 X& f, S5 F: q5 t2 f8 l+ N
1 M# |$ m+ B# g' g函数名: restorecrtmode 7 `$ D, ?$ i! B4 f8 F4 z' T2 j
功能: 将屏幕模式恢复为先前的imitgraph设置 : L! J' [0 d- H6 R. g
用法: void far restorecrtmode(void);
6 a. C ^- f$ b* V5 C: E9 y& B程序例: : W+ |" ?1 W- u1 f$ Z
#include <GRAPHICS.H>
% k" h( F( _; v: r) n9 P1 D2 l#include <STDLIB.H>
$ ]$ V1 L6 }3 y6 n#include <STDIO.H>
" P# Z: T& k* P# b$ w+ w#include <CONIO.H>
- P* b* |3 R9 J/ N% A c* r: Lint main(void) 1 I5 |! w5 U3 c* B5 y/ R+ @
{ ' X0 i B; T5 i
/* request auto detection */
' q4 h6 @1 F5 D4 J5 _int gdriver = DETECT, gmode, errorcode;
( n$ X7 w4 a+ Q( S5 hint x, y; 
# \9 u6 Z& \$ ]. C; Q/* initialize graphics and local variables */ 9 v6 [( K2 Q% g5 O! p" Y& J0 k
initgraph(&gdriver, &gmode, ""); 
6 a9 S# v5 M" q0 T' q/* read result of initialization */ B/ v: t0 u8 p+ f7 Q0 I8 ~
errorcode = graphresult(); $ J4 _: A! B5 h
if (errorcode != grOk) /* an error occurred */
5 |4 P. y8 g: e& G1 s8 m% U{ $ ~3 f' W$ ~6 h. w- X) @
printf("Graphics error: %s\n", grapherrormsg(errorcode)); # V* @" K3 ~8 ?2 j5 H. ]
printf("Press any key to halt:"); 3 e6 k) V* E& [: @6 I
getch(); 4 d, F9 j6 u& f& q6 z. U) a
exit(1); /* terminate with an error code */
$ s3 _6 r4 z$ L4 K} % d8 f. o8 i: L# a
x = getmaxx() / 2; 5 g0 X/ V" L5 h4 U5 u
y = getmaxy() / 2; 
7 A# N2 g I! `( F$ o* y U/* output a message */ 6 @/ z- [) m! {! }
settextjustify(CENTER_TEXT, CENTER_TEXT); 2 A }. Z: O( i7 G$ Z6 m
outtextxy(x, y, "Press any key to exit graphics:");
7 N2 Z$ v8 W! h8 Agetch(); 
4 \& o* _( j) }/* restore system to text mode */
5 x* }9 v" N' |$ @8 Srestorecrtmode(); , j: H$ i/ \0 Z2 ~0 x3 V/ t
printf("We're now in text mode.\n"); ( b g' q. A+ s9 H, h! m
printf("Press any key to return to graphics mode:"); 8 R! Q& [; D+ D* u' B
getch(); 6 L# M- R" b- _# I) ?6 n
/* return to graphics mode */ $ F3 ^: b7 `" q; C, e; u: |
setgraphmode(getgraphmode()); 3 E; p( w, I) L1 Z7 o/ H
/* output a message */ 2 b( ]( P. S# s% w5 \# i
settextjustify(CENTER_TEXT, CENTER_TEXT);
$ _; g, n% V6 b. xouttextxy(x, y, "We're back in graphics mode.");
$ J$ W5 z* Z% Y- _outtextxy(x, y+textheight("W"), "Press any key to halt:"); - E+ J% U) n+ [7 Q# I* a$ u: h
/* clean up */
9 u6 A& F, O$ S) ]+ n- _getch();
- w2 e. a% v( ]/ v( ]closegraph();
% ?# |+ @( ^8 x. Kreturn 0;
* {' f# }" R# y4 f& ]}
0 l4 A7 c, g, ~ J5 j% g( k
( Z; S H/ d% B5 x" g m4 u+ P, {/ z A" L& G z
函数名: rewind : s0 a" k' w6 F
功能: 将文件指针重新指向一个流的开头
6 _' k" F8 o/ d用法: int rewind(FILE *stream);
9 P% T, H' ?1 Q4 S0 _3 H7 W程序例: ) \" S- x' Y' t' A4 |' U, z& J
#include <STDIO.H>
2 K- q* F) b7 A: F; [' d#include <DIR.H>
7 O. T6 ~) j& c! Pint main(void)
1 l+ L, C$ o; G/ k{
. @* g& ?+ @+ \$ {7 I' H! BFILE *fp; + p3 M( P6 @: V0 W2 x
char *fname = "TXXXXXX", *newname, first; 
4 G! u4 t8 e% f/ D( x8 W3 i' }newname = mktemp(fname);
/ f6 ~5 r8 \6 V7 {3 h- r! l7 }fp = fopen(newname,"w+"); 0 i1 l9 t2 W9 k2 I8 b1 A0 X* i
fprintf(fp,"abcdefghijklmnopqrstuvwxyz");
9 T' y/ f2 t1 J5 @: hrewind(fp); 8 M3 \" ?1 }. F& x( J/ @
fscanf(fp,"%c",&first);
9 _ P+ [8 h: F3 n, kprintf("The first character is: %c\n",first); , ]+ v2 m1 G3 O
fclose(fp);
$ ~3 ~4 q! f# \( L& R1 _remove(newname); 
+ U5 ^4 C' Z7 S: Creturn 0;
6 A; g% _/ f V; x. o& G) m$ V2 j$ u}
3 z, ?! E) q. y6 R" u! f( A+ Y
5 K: a+ a4 V( l, i3 _3 i3 ~$ F- j; _' g# ?( B/ L# f
函数名: rmdir 
$ P6 K+ C9 {8 ? Y/ z8 W功能: 删除DOS文件目录
8 D8 {9 u% ^2 s$ G/ E; [用法: int rmdir(char *stream);
& O4 y. U# {5 @3 \+ s3 F* ^) V程序例: ! z9 N% l: _; L0 _$ T$ I, f! }
#include <STDIO.H>
3 M0 k6 L! m6 l, ]#include <CONIO.H>
9 S( Z$ s8 m. q- K$ Y9 ^3 p. r#include <PROCESS.H>) Z9 {4 @; m4 t( o: M* h. C
#include <DIR.H>
7 f, x- a" @* }/ c8 l3 m) u, T$ T/ `#define DIRNAME "testdir.$$$" 2 d, t2 {! j) c( l8 Q- w
int main(void) ; `( W4 ^* M, p! w+ F. e# W, T3 _
{ 5 Q1 S+ l A% P" @$ q
int stat; 
7 D* [9 ^6 g- i6 Istat = mkdir(DIRNAME); 6 z z/ z% `4 u" j$ T' S
if (!stat)
! E" C s2 k: {& r# Tprintf("Directory created\n");
) I9 g( |+ U- l n, Gelse
; R- m1 B/ G( A* \8 {! C) F{ - L9 t3 n! n) q2 y; m1 Y7 x3 _" P
printf("Unable to create directory\n");
7 ^9 P0 W. H" kexit(1); * z7 X' J" P3 @7 q
} 
* s$ N2 Q& w; k' G, m) [getch();
$ S2 b# l1 z1 U k% U* Bsystem("dir/p"); 3 ^# c7 u$ T+ u! D' X5 X7 ^! g0 [
getch(); 
1 g$ {: A7 |1 H" D. h4 e9 U8 lstat = rmdir(DIRNAME);
3 ^9 }& C1 ?+ J8 D X4 l+ Pif (!stat) $ L2 e, q: M) R: V* N
printf("\nDirectory deleted\n"); $ h; Z' h3 Y9 w9 b
else - C, n2 W. F' V0 a. [( }
{ . d0 Y2 |+ i0 I
perror("\nUnable to delete directory\n"); - U1 V8 d, E7 B4 N# w1 D) A: n7 d4 J
exit(1); 2 ]( @, G q) e- ^) I1 }
} 
7 a; Y# y) O! y$ h0 `, |' Lreturn 0; ! \( k2 o4 q1 P W/ f; L% x! }
}