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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); - ]/ _' R: @- u" z
/* restore previous dta */
2 Z/ c: Z; R9 Ssetdta(save_dta); 0 C* T4 b3 _3 Z
return 0;
! i* L8 E1 G) l( q- ?6 l} 
* M- V; O+ D+ p R1 x# Y; I4 m% m B' x0 t
函数名: randbwr 
, `+ P, y6 ]# W" ?* F9 E# {功能: 随机块写
. |) \. I0 t/ q+ I+ O5 p8 B4 n& P0 _% Z用法: int randbwr(struct fcp *fcbptr, int reccnt);
3 G8 x+ r5 U" o; }; z6 A' A9 f0 p程序例: 
8 E8 t' g8 W) e0 p4 P#include <PROCESS.H>
' G/ J) e c* s#include <STRING.H>
8 {7 j0 K* ?+ S5 r- h T% l#include <STDIO.H>% |4 B: w; z3 O5 Q9 D
#include <DOS.H>2 p$ U% Q# {# m; N
int main(void) 1 R) _7 Q4 a' U/ ]7 z
{ ; [( `, R' ]' q9 [+ {( `
char far *save_dta;
 {: }. Q# ?, I% _. m, Jchar line[80];
8 U |% [% u$ S$ Uchar buffer[256] = "RANDBWR test!";
: k1 ^: @. j$ V* `! Nstruct fcb blk; 1 W! R+ l: N5 j4 i
int result; 
6 }+ }1 z& o# f- A9 o% h/* get new file name from user */
* x9 ?* c& [1 v T7 S8 h0 H s) sprintf("Enter a file name to create (no path - ie. a:file.dat\n"); - t) W* V$ }' P
gets(line); 
/ F1 f7 S7 D: h( w$ @0 \ Y/* parse the new file name to the dta */ : {, o0 p7 Q) }% |) @. r
parsfnm(line,&blk,1); 0 v9 j& C3 n3 c& S
printf("Drive #%d File: %s\n", blk.fcb_drive, blk.fcb_name); 
) V' M. o6 Q$ q4 Q4 j+ R/* request DOS services to create file */
. ?: S. [' U: U! S" E+ |if (bdosptr(0x16, &blk, 0) == -1)
4 b( _1 X( \5 \5 E; ?0 u{ & U1 [" B5 m" [$ n3 D
perror("Error creating file");
- s- |8 h0 \' w% y2 K3 oexit(1); 5 f4 f4 z6 w" [2 N4 z! f
} 
# b8 ?2 h& ^7 a8 [; e5 y* A# v/* save old dta and set new dta */ * p5 b4 j+ b( H3 y
save_dta = getdta(); 5 N% ]+ _" }$ e) B
setdta(buffer); 
' k- ~; L& | q! F9 f" f/* write new records */ ( V% j5 ]7 h* ^. ?4 B
blk.fcb_recsize = 256;
3 _+ _* Y% A; w0 Ublk.fcb_random = 0L;
, [/ P: M) @+ n& D0 i+ sresult = randbwr(&blk, 1); c( c4 k% g1 o" {& }' b2 P
if (!result) ' `- R! {. e4 S
printf("Write OK\n"); , y* o/ k- p. N; m$ z3 i
else 5 ~) D- W5 y2 {5 L
{ / J5 i4 }% \' I
perror("Disk error");
4 A: e* c5 P6 A0 @% sexit(1); ! u. ~- x8 C1 H0 Y8 m
} & u% L- s9 \" d
/* request DOS services to close the file */ * `% p0 Q2 |1 Z1 r/ P2 S$ R
if (bdosptr(0x10, &blk, 0) == -1)
( t, F. E; }# A( i& i{ 4 z1 p( `, h ?' M
perror("Error closing file");
) D' y8 H% ]. R0 W$ [! g7 o2 jexit(1); # j3 l$ f9 L" `4 K
} 
; |; { k/ l; h& c3 k( D/* reset the old dta */
8 i9 I5 k6 @0 W6 l* Vsetdta(save_dta); 
" q6 U; J% G3 J- Dreturn 0; . \0 H/ M, s S; u* V. y! z% ?4 ~3 s
}
# p7 j5 {/ Q" T5 U5 \" |9 k
3 G. ^/ L4 F2 `3 Y2 l5 V
! |2 S5 H( D4 @3 O5 ]+ {2 i j函数名: random 
* L# ~* p) D3 N# h功能: 随机数发生器 ! M' R) Q% y* M
用法: int random(int num);
2 D7 W; o8 M4 {7 P, M程序例: 
% ~; z+ h& _" E. j8 T#include <STDLIB.H>$ S1 a% O1 w) n R! {( h
#include <STDIO.H>
. ~) u7 ^% r: h' _$ n- W ~9 A#include <TIME.H># Y( s; P' k0 d2 M6 X5 N" K
/* prints a random number in the range 0 to 99 */ : ^% u: f, F$ G8 c
int main(void)
' ] d$ C9 F+ \' \; ~/ d) h: w+ z8 i{ p* V" \$ o9 I# h: Q% w& C3 A
randomize(); - y* E3 o1 X, i$ v, K A6 W7 _
printf("Random number in the 0-99 range: %d\n", random (100)); , m* R; k. {; e6 ]! m
return 0;
- M$ w( Z0 E3 k w& [5 S( f} & c4 T, K; n- I
% b/ H1 e0 s) `5 X' f& I/ \ W
/ z( z: k! U: t# o# W7 X
函数名: randomize 
! L$ r3 c: D/ }, Y9 ?! Q! u功能: 初始化随机数发生器
7 `& P9 k" W6 G6 N% {# i+ q用法: void randomize(void);
* j( [+ E$ Y8 x7 S" r. Y9 r0 L程序例: 
7 L. L, k. U; f( v# `" w5 t#include <STDLIB.H>& n i2 D9 T! V5 u, q
#include <STDIO.H>. _8 l* h2 M4 G3 o
#include <TIME.H>
2 r. w2 n5 @" y# mint main(void)
6 s9 f- l! t& B! c{ 8 v# Y- u( q" ]) V8 |
int i; 
& p3 A1 c, X# i& Nrandomize(); 9 T0 P( u( b6 r" S- S! U$ o
printf("Ten random numbers from 0 to 99\n\n"); % ^8 Y* M5 T% j: O
for(i=0; i<10; i++) ) ^* o3 S; L8 b. t" z
printf("%d\n", rand() % 100);
: H$ n) p* P: e& }2 r( o/ ]return 0; 0 `4 _- x9 X* V e$ @
}
% `9 B) J* u9 i( u
! g( j" O3 {8 Z, C$ i: @! e
5 X8 B: L4 y1 ~* Y" R函数名: read ' ~/ ?& H+ [3 N
功能: 从文件中读 $ x" [/ _8 N3 [: n* Z& k" n
用法: int read(int handle, void *buf, int nbyte); 3 j3 U. L. d) E/ I) [/ |
程序例: 
6 c2 }$ |7 _4 A# |" X5 c0 G#include <STDIO.H>
% f! j2 I4 Z6 W#include <IO.H>8 d' [" f- a) C
#include <ALLOC.H>( E, G& i2 ~% l% c
#include <FCNTL.H>
6 X! ^4 b! U1 h: R! s#include <PROCESS.H>
& n" d0 j$ Z! E0 p5 K, O* g#include <SYS\STAT.H>
/ I4 {. Y) z) o) I3 p0 Wint main(void)
( x& ?: i* S; @$ Z, @$ p) I{ & C$ \ ?; c# E$ t
void *buf; 2 A# M0 P9 r& Q
int handle, bytes; 1 o% [! d' C G4 E1 y% ^7 `
buf = malloc(10); w! @) U4 E+ t% l8 G, J5 H" q
/*
 C& ?$ R6 N8 Y; [' z- |- QLooks for a file in the current directory named TEST.$$$ and attempts
& _ B2 `0 N q' F1 j. C& Bto read 10 bytes from it. To use this example you should create the ! ~3 W) P: b* U* L5 x
file TEST.$$$
7 V; l- q0 v! o, }! F& M8 u*/ # \# ]% b4 A+ N: u7 I$ G* s9 h
if ((handle = ; B9 k1 o* u# C& P( M/ t' }/ C& f7 ?
open("TEST.$$$", O_RDONLY | O_BINARY, S_IWRITE | S_IREAD)) == -1)
9 ~6 n, P0 N2 c, U" z+ S{ / w) U3 Y7 @+ S5 }* z6 G
printf("Error Opening File\n");
' @7 I5 ~ {' B6 r& c0 L1 E% nexit(1); ; @! Y4 F9 V7 |1 e4 ^% V
} 2 u4 \; l) T3 @5 @& B
if ((bytes = read(handle, buf, 10)) == -1) { , {8 a7 A! ?; `. t' k' \
printf("Read Failed.\n");
4 g) g Y7 d; P* Z& W3 B* J. }" Jexit(1);
5 ~+ |+ n. ?% z4 c+ S# c& Z}
* j+ H9 Q/ v9 A" ]$ \else { # ]; p1 Y1 U5 I q- d1 h+ z
printf("Read: %d bytes read.\n", bytes);
8 M. L/ Q$ \3 @/ o( B3 s}
; {1 k- b6 S2 V& a3 @, ureturn 0;
" S v% R J1 h3 c; f8 y" `( {} 
1 G5 h. X# L, ~4 W5 H' z# ~6 a' v7 \6 s

8 K. l9 |: m% d0 a函数名: realloc 
8 S+ K/ o4 S7 H3 a& Y功能: 重新分配主存 / _6 X7 y/ Y5 x# l# u
用法: void *realloc(void *ptr, unsigned newsize);
4 ?2 _# J: q% c1 o; s程序例: 5 o4 n0 j) I( z
#include <STDIO.H>/ n9 X/ w1 H+ L8 U! R
#include <ALLOC.H>
! r7 Q7 ]4 U8 ]- F#include <STRING.H>
3 i7 D. R/ _4 b! i: G' Z* ^int main(void)
4 A0 Z4 j% q0 A6 R( A{ + x; I2 ^. m ^8 W/ G
char *str; 
7 p D8 T8 X! y$ K+ Q# n/* allocate memory for string */ * g: t5 j" i+ K p
str = malloc(10); ' i' T+ n5 Y7 s
/* copy "Hello" into string */ $ d8 n/ I3 j# L
strcpy(str, "Hello"); 
+ @3 A6 v0 m8 T, w u3 E& Sprintf("String is %s\n Address is %p\n", str, str); ( {' l, O7 |6 s+ E( b4 W
str = realloc(str, 20); " F7 g; C5 j8 ?4 Y4 G
printf("String is %s\n New address is %p\n", str, str); 6 L& Q1 v/ O0 k, h$ ?
/* free memory */ 2 i& x- s( ~1 I7 o3 ~4 n% S
free(str); 
, n8 N2 O: }9 D- D3 b: u& t, a- _return 0; 3 q$ `: u- l: q' T3 Y- R
} 4 g( k6 [ Y1 S6 b3 n4 Z

/ T- d0 W; `0 J _3 [& Y* T: ?) Z# N. h. r6 F. x- w" M
函数名: rectangle 
, W, c: O2 L6 E0 F功能: 画一个矩形
; Z2 m0 a0 t }5 h+ Y; b2 K用法: void far rectangle(int left, int top, int right, int bottom);
! J. n, u; E! @5 u6 c$ y7 i程序例: 8 U% g- ^6 e4 ^- P) Y- t1 g. x
#include <GRAPHICS.H>
5 i9 D: b* v% H% L#include <STDLIB.H>/ t1 G2 T3 N1 j7 r1 L7 Q
#include <STDIO.H>
1 D! O$ |* p1 ~& j#include <CONIO.H>
$ K1 m: N+ G1 L( R) B w9 Bint main(void)
7 S7 ]5 g X4 V, M) o0 @& x9 a) \{
( W. ~9 T4 ]8 y2 r/ T/* request auto detection */ " q& Y' B$ H0 R* ?
int gdriver = DETECT, gmode, errorcode; & D! R8 [! P( Q! {! J
int left, top, right, bottom; 
: ?2 V) Y! b% x( x7 Q/ Q/* initialize graphics and local variables */ 7 w0 k- F9 T+ Y
initgraph(&gdriver, &gmode, ""); 1 w3 U0 @3 U4 K" y" ~& E: l
/* read result of initialization */
: P" v! w3 c6 D% c& j. [errorcode = graphresult(); # [" M6 r- P. b" E" y
if (errorcode != grOk) /* an error occurred */ # Y! e. {- Y! q7 T4 y; F
{
& W1 O O8 J( B) ?9 q* dprintf("Graphics error: %s\n", grapherrormsg(errorcode)); 9 u6 J" v1 `! l+ z
printf("Press any key to halt:");
/ G3 c2 D) D# l) N, Fgetch();
% g2 n6 a1 F' F0 ?; Z5 o" t. vexit(1); /* terminate with an error code */
* i$ H D" t( A/ G4 Y/ ^} 
/ m6 o) b' n! K' V; ]0 N5 @% G5 eleft = getmaxx() / 2 - 50; # R4 s; u% M, v5 y/ [! R
top = getmaxy() / 2 - 50; : |! _9 B- o! k8 H- `, @
right = getmaxx() / 2 + 50;
" C0 Z# E% j$ o4 H# w- I- X* Wbottom = getmaxy() / 2 + 50; ! t4 J% O4 p6 @! ?
/* draw a rectangle */ & R" k8 n) [* a+ z$ N* k
rectangle(left,top,right,bottom); 
% p* M) \% Z! E9 j' l. J- ]/* clean up */ 6 P7 D4 P! y9 Y# A3 Z
getch(); + l: o% T% S: I1 z( Z2 g; H( U" s
closegraph();
( ^8 f- V. \1 o8 E0 {3 Y. @return 0; * B! a$ j3 \8 _$ {/ G: k( E0 r
}
7 a! V8 F, [; w8 W5 B9 U8 ]$ {
8 }/ X/ l3 _7 ` A
( A, z( b1 q* K* V函数名: registerbgidriver * c- |7 g2 c& l5 M
功能: 登录已连接进来的图形驱动程序代码
& X% T8 [, p0 e6 |& M2 m2 h7 z: v: J用法: int registerbgidriver(void(*driver)(void)); : ?2 n4 z* }7 ~! o, u
程序例: * k5 b+ Z, Z/ @% c, w
#include <GRAPHICS.H>5 r; l" o+ {; Y$ F: d9 q
#include <STDLIB.H>
3 o: N3 Q( g% L: C9 \/ k8 L$ G. U#include <STDIO.H># h' g8 O) S) U1 N
#include <CONIO.H>
7 X8 K( W3 `3 W) ]/ m3 \% m4 \9 Kint main(void)
4 p" {! R/ U6 B6 ?: O* I{
) ^2 _7 x9 b7 @1 r* s" x/* request auto detection */ * Y) Y: a- J& n% G- M. s
int gdriver = DETECT, gmode, errorcode; 1 T* N4 F. v8 }& ?; x
/* register a driver that was added into graphics.lib */ 0 S; y* e' n2 v7 A: p. m2 X
errorcode = registerbgidriver(EGAVGA_driver); 0 m s3 T6 m" J7 Z0 h
/* report any registration errors */ * [+ y- |0 }9 t# D: B8 T
if (errorcode < 0)
2 A8 b+ a, H& f6 B{ # H6 r" z) L* B3 f% d
printf("Graphics error: %s\n", grapherrormsg(errorcode));
2 I* b7 ?* h! {$ w. _printf("Press any key to halt:");
# i& G5 a4 A9 k L% J; kgetch();
% D% v2 r6 C$ o5 R2 dexit(1); /* terminate with an error code */
- ]2 j1 y& V! H, d} 
7 C! @9 k, F" U- s$ m2 ^" [/* initialize graphics and local variables */ ?8 Q" L+ a n6 n1 R! O, D
initgraph(&gdriver, &gmode, ""); 
: ^* [) P: i9 _0 s1 z/* read result of initialization */ ) E9 B" l' r1 f- e! j. f/ F& r
errorcode = graphresult();
& |0 W+ }) \( ^if (errorcode != grOk) /* an error occurred */
# G6 D" f1 r, S# m; p$ _. x{
0 }9 |& Z1 F4 a6 r: r$ A( Xprintf("Graphics error: %s\n", grapherrormsg(errorcode)); $ t- H; L* |- }; I
printf("Press any key to halt:"); - f" G+ J; R% i
getch();
) u. e! {3 G9 k( u) }9 m, ^exit(1); /* terminate with an error code */
5 z3 H/ Z; m; D} 
) |- n( C) U7 n1 C5 X: K/* draw a line */ 0 w# ^$ c* A# V6 I& t
line(0, 0, getmaxx(), getmaxy()); 8 P8 R; l4 }$ w9 p0 Y
/* clean up */
% G7 ?1 Z" g8 k- c# i- egetch(); 9 o# ^4 U( j |, R( v( v3 }
closegraph(); 7 Q' b. j4 H/ W: f4 i [6 T
return 0;
) d- s/ [) e& |6 N9 L0 T} N) ^$ [0 X, h7 v' O6 c" ?

1 F m% W/ ~& p: G8 a7 b, z0 x4 O: }9 k0 b& P: u H$ d" Q
函数名: remove 
# M& j& d% X: k8 W" `, n& I功能: 删除一个文件 + t* p, R- j" v; t1 t9 M: ` C/ c
用法: int remove(char *filename);
" ^7 P8 k K, m/ H) r4 M程序例: ; [# P" W: j. |* k7 p- n6 t# ^9 @ N# x6 V
#include <STDIO.H># `0 m& y4 t8 Y0 L9 W) t
int main(void) - {! W! y% Z& U9 Q. s1 B t+ \, ?
{ ' H7 A: d# A* ]/ I L
char file[80]; 
8 b6 q% p" b& A( h* U/* prompt for file name to delete */ * R! f5 z3 X' l$ _4 p8 j# J
printf("File to delete: ");
2 @- Z8 M; F$ p: P' Ggets(file); 5 W9 E- M* r4 r* E; g* B5 Z
/* delete the file */ ! V0 J( v$ f! x0 n7 X1 [9 s: [2 z
if (remove(file) == 0)
! x' {, @) S4 X( q! i' Vprintf("Removed %s.\n",file);
! @( y9 c5 E- M6 c) X2 delse
' v- S/ r0 V7 N3 b) G, \2 \+ }perror("remove"); 5 M; B$ N2 S8 d# z% V
return 0;
4 r, L$ b7 X. o* L: w}
: d7 E9 N6 q6 T: O9 a: }- K, b* U4 o# a
; o* K- H% C2 ?" Y
函数名: rename 7 T- n1 P1 I, H6 e9 V4 P& c2 {
功能: 重命名文件 8 F F; i( ?. q' c
用法: int rename(char *oldname, char *newname);
: e* V! w9 ^+ `# e$ y. h7 X程序例: ' B; [% t# H, z8 L- X6 r5 f3 ~+ E
#include <STDIO.H>, z J0 z( K5 a! H+ C6 }4 Q3 K8 g
int main(void) & \. o5 N5 d7 o/ Q
{
! O1 A3 Z, c0 o9 ychar oldname[80], newname[80]; & A# x! x" I2 j1 ^( ?5 N( c& d' C, S
/* prompt for file to rename and new name */
9 P' `8 R& X! H- B' uprintf("File to rename: "); 5 l, r; U; c- P8 S3 Q
gets(oldname);
+ c: y6 ?; @! U8 u8 E% c8 Qprintf("New name: ");
& q1 {& b Q- A( ^5 U' pgets(newname); 6 x0 D3 ?) _/ ?: b
/* Rename the file */
if (rename(oldname, newname) == 0)
1 U e- w- n/ hprintf("Renamed %s to %s.\n", oldname, newname);
7 N* D7 l. ~ S, r* e( D2 Eelse : q6 l' d9 W6 y' p. N1 o. ?
perror("rename"); 
' h6 M* ?# [3 c" ]return 0;
. x5 c' Y& N- g} 5 G3 E# j/ _+ S/ C3 K3 t, |& {: ]/ n

* ~1 G* C' [& ?' ^ |, J/ Z. ^0 }# H+ t* Y& R" V5 n# t/ \, k6 ]
函数名: restorecrtmode 
/ ]) }! p8 G5 C, S功能: 将屏幕模式恢复为先前的imitgraph设置 0 i# P5 d) |$ w+ g
用法: void far restorecrtmode(void);
$ v' n: C9 w9 O4 G2 I# S程序例: 
) O$ Q3 S+ S# @9 G+ q#include <GRAPHICS.H>7 \" z& Q# ~9 \/ }# i. W
#include <STDLIB.H>
' q( @) @+ a( l#include <STDIO.H>
9 K' I8 v! y. G% n! z#include <CONIO.H>: C3 E0 k+ [, L& b6 |1 `0 K) w
int main(void) % s+ S* Y! D8 h* Q) F8 }/ ?
{
+ S, |8 b# f2 a, t+ V/* request auto detection */
, o7 q& Z: K; X$ K y' bint gdriver = DETECT, gmode, errorcode;
$ h9 N# o; r. d. E3 a8 I- Dint x, y; 
) q. u. V- L Q, ~& t# ]) L/ Y/* initialize graphics and local variables */
9 d* _' Y V, W8 O4 q2 t, p3 einitgraph(&gdriver, &gmode, ""); 
" K, n' P2 l, P. y/* read result of initialization */
, Y5 U' m* F8 W5 p) y) gerrorcode = graphresult();
 }* y1 s" a: Iif (errorcode != grOk) /* an error occurred */
2 | x5 \( b. n' f4 w{
8 a" x6 C9 O6 \printf("Graphics error: %s\n", grapherrormsg(errorcode));
4 v" y: k: I( Z& eprintf("Press any key to halt:"); ' f; \0 p, k# w% h' s" Z& }
getch();
- R6 N! S# H9 }8 ~& @6 T5 V7 Wexit(1); /* terminate with an error code */
5 r' \( b0 E0 e} . O$ [5 {7 s1 i) R
x = getmaxx() / 2;
5 J; o+ _) f) D+ o1 K% t' [y = getmaxy() / 2; 
 x, x6 r" v2 ^- n1 X5 E) i/* output a message */ 5 _0 u: Z, ^4 a: p J% w- E
settextjustify(CENTER_TEXT, CENTER_TEXT); m3 g! k1 w3 f$ D
outtextxy(x, y, "Press any key to exit graphics:");
5 C- m1 N3 s) p0 J0 m: w0 R% [getch(); 
5 C, y% J7 o) [% E) G9 x/* restore system to text mode */
7 a' v+ I p; }: Xrestorecrtmode();
" _ Q* X( K" \# u# r5 F# l Zprintf("We're now in text mode.\n");
* m# e. ^) q$ I. fprintf("Press any key to return to graphics mode:"); ! B+ c" N3 B, t2 Q6 M9 f3 ]
getch(); 
0 [* l |: M9 l; v6 _# F1 v/* return to graphics mode */ " A) ~- I K4 a7 q, W# G2 ]
setgraphmode(getgraphmode()); ! Z7 I1 S8 N" ^7 p# Y6 ~
/* output a message */ * @' ?( `2 N6 m+ \. y( J: N
settextjustify(CENTER_TEXT, CENTER_TEXT);
; C1 Q! _& [) B" ?3 youttextxy(x, y, "We're back in graphics mode.");
* p$ Z) d* G& d; Bouttextxy(x, y+textheight("W"), "Press any key to halt:"); # {, @# \, I: w4 v1 W
/* clean up */ 5 Y2 \( U% T9 F( a0 b" }0 V1 V
getch();
: f$ w* S$ w7 a2 p# I$ ^, E" u5 |4 Kclosegraph();
& L0 V. M( E# }return 0; ( o/ `2 q6 [1 o
} 5 X" `) w n9 Q

' D" g; n+ H* M) c" i0 P; n, V9 N% p S, m/ Q- j: _$ U8 z
函数名: rewind 
; Q) D) q. N/ m/ ~# H功能: 将文件指针重新指向一个流的开头 % U/ H" i/ E! }
用法: int rewind(FILE *stream); * x- @9 J- H8 J" d+ n; |
程序例: 
+ m: [6 g( P& f4 ~) e#include <STDIO.H>
1 z8 O; u9 s7 a9 c0 q#include <DIR.H>
7 {% x; X' c2 ?! a! o( Yint main(void) ( ~4 D& E. I3 k8 |# o& j& |6 e3 t( ?
{ # a/ V' H! y! D4 U! N
FILE *fp;
. F4 \2 C& s* ~0 Schar *fname = "TXXXXXX", *newname, first; ; M- q. }: F! L) K! Z
newname = mktemp(fname); ) B% K% S- y( H
fp = fopen(newname,"w+"); 7 F, S/ z2 w$ u4 w
fprintf(fp,"abcdefghijklmnopqrstuvwxyz"); 2 U% b# o4 U t' b" S- G/ E
rewind(fp);
: N; r/ j/ a* [fscanf(fp,"%c",&first); 2 [5 `. J$ |: n% y( q
printf("The first character is: %c\n",first); 4 u4 y, b# O( j5 f' S+ H" G
fclose(fp);
. r* D6 @ h. w: B' nremove(newname); # E1 w+ B! [- }3 }5 @
return 0; ( G! m! L/ J2 d( M8 ^2 U* v
} 9 x8 ~8 a5 }% l% g9 H. y/ t4 U+ E
, ]; t F K+ c& S1 M) t

( ~; H' N6 V1 |! y8 C函数名: rmdir * z3 i [( ~4 b0 s- t3 D
功能: 删除DOS文件目录 % P; v" e% Y' @4 E: V- G
用法: int rmdir(char *stream);
' q9 q% T1 S! \0 x程序例: ( b1 x) H8 @$ \: {3 e
#include <STDIO.H>
* U+ Y- S; X. H% e, I# ?#include <CONIO.H>! Z& @! A C+ t+ D9 A4 k
#include <PROCESS.H>
! g9 a6 O/ X/ P/ i! L#include <DIR.H>
3 U$ }2 n7 p8 D, V#define DIRNAME "testdir.$$$" % U4 b+ f" t# w0 u0 U" e! K9 F6 x4 e
int main(void) " [6 f/ _- ]5 S$ U- |* H6 D
{ + F0 p5 n, e% v7 ]2 o; w4 R
int stat; 8 C$ [- F2 g, F) W! z- {1 B4 k) A
stat = mkdir(DIRNAME); . _; u, K( L/ F# p8 R _. X2 _5 E
if (!stat)
. K5 [5 S! Q! r& h5 I8 Eprintf("Directory created\n");
# O" X3 G" M. q6 U; `; nelse
2 a" Y5 J( n# h+ q{
+ N% B4 r3 i/ C' E; rprintf("Unable to create directory\n");
' e9 C* I" l1 ]4 m9 C, {exit(1);
% q1 @; K7 E1 ], q: i* [8 E} 
6 ?6 b1 S. A! D0 Y, i2 X8 o- Ogetch();
. J6 R+ \2 |3 lsystem("dir/p"); ' w. ], r D9 f- g/ D- o( z# S. G
getch(); 
: S5 W) q6 i: M. _+ A" Estat = rmdir(DIRNAME); * w+ T% J H8 `, O+ Z' f
if (!stat) - ^, {3 Z* n/ l1 ^. D
printf("\nDirectory deleted\n"); 6 Y) P( h3 h, h5 y6 @9 W
else
# r! U! G6 q. q! q$ u1 S& P. V{ ' e' _: ?% t, ~; T( P
perror("\nUnable to delete directory\n");
; E$ E+ ~: N0 S: G( O6 mexit(1); ( {9 |, A, s' l5 E
} 
; G, A$ @' T G& H4 Nreturn 0;
' M. R; f5 [5 ^* P$ p5 y6 {- [}