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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); 
% J* h$ D, b4 \. u: q/* restore previous dta */
& W( u# g2 k; Gsetdta(save_dta); 6 Y: A: t @; j& j3 C( N3 F
return 0; 4 u3 k2 `, `* Y' Q
} ?& s0 W# Y# b' @% P
* {; C; P$ Z1 V3 \
函数名: randbwr 
5 r! }) ~9 G/ n: F0 u* [8 z功能: 随机块写 / N1 k' C' h& r* x
用法: int randbwr(struct fcp *fcbptr, int reccnt);
' A0 \! r9 E( M, G' c$ D程序例: ' }$ @+ E0 v: W5 Y1 h$ A) h4 n" _
#include <PROCESS.H>: V( l! S- P3 b0 x" ~
#include <STRING.H>
& M* [6 y/ O7 ?# @7 o#include <STDIO.H>
7 J( h( V; F" ]" t* L#include <DOS.H>
( ?% s# E, K0 ^ ] Z3 ~int main(void) 4 h4 e$ U* a( w9 _4 B% t
{
9 u9 \' b- q% _" h( ]0 U: ychar far *save_dta; $ b( U }. I, r6 n' l9 l% n
char line[80]; 2 N! h8 t/ D1 h
char buffer[256] = "RANDBWR test!";
4 s/ _, b, A3 {% y( sstruct fcb blk;
4 s# r0 n7 q7 ]" i( v5 ~int result; 
0 _/ O' L! q8 ~; e) {( B2 i: k/* get new file name from user */
/ B" [- g6 i; ?' h; xprintf("Enter a file name to create (no path - ie. a:file.dat\n"); # {' c/ N+ K" J
gets(line); % ?1 L: P4 f- Y- k) C& r
/* parse the new file name to the dta */ ! Y7 ?) u+ N' E6 d; K. ]
parsfnm(line,&blk,1); 6 k: \2 s+ P5 p* Y7 W3 f
printf("Drive #%d File: %s\n", blk.fcb_drive, blk.fcb_name); 
5 ~. R5 c: _) P f5 J2 g/* request DOS services to create file */
& L4 I% C# T1 M" A; ~3 U+ y/ Tif (bdosptr(0x16, &blk, 0) == -1) 8 `, H+ T; Z# z3 {6 H' }+ x
{ , h/ ?. S, f/ h" d' r W/ w/ L& I
perror("Error creating file"); 5 ~8 x7 p$ x3 g! \
exit(1); 6 S8 A* h% g9 V
} 
3 Q! w8 i6 S+ P" M% z/* save old dta and set new dta */ , \0 u/ S3 I% a) p
save_dta = getdta(); : r; K+ U6 F/ S/ a; [
setdta(buffer); ! e2 P( e; L/ y( {, N
/* write new records */ ( U Q+ f% A. a5 D+ m1 I! y/ I
blk.fcb_recsize = 256;
8 P/ D% s! Y8 k& J8 oblk.fcb_random = 0L;
# }# }7 e; s& T& I) ^ o+ D+ Dresult = randbwr(&blk, 1); $ I( i9 o6 _3 `2 c
if (!result) ! }- c6 j. j |3 n9 Q/ k8 I" A6 ?
printf("Write OK\n"); . m' \5 h/ u+ z4 I2 o
else 3 k5 A0 t0 d* B0 ^% C
{
% b `, ?- Y) _3 @7 n3 _perror("Disk error");
0 }+ Z: m) A/ I cexit(1); v$ S- _) P) z" X6 Q7 _3 Z
} 7 E% t+ C8 p; n9 `' m& L& s0 e$ x# _
/* request DOS services to close the file */
( v% {# }5 ?( O0 C) w( w( d: }if (bdosptr(0x10, &blk, 0) == -1) 1 j: z7 k: k3 [7 m9 D
{
6 v# W) C# d1 Gperror("Error closing file");
* n# R9 C0 D& q5 Rexit(1);
+ m$ b4 [& G/ @! U; o) Y} / p" r& W/ y1 V
/* reset the old dta */ % Y; `5 u1 n' l5 f2 \: U* ~' {
setdta(save_dta); , G' i) S6 S X9 H4 s( y
return 0; 7 T8 ~# W, q% d
} $ b# t, _0 }/ B' z2 o; X3 n# V/ r
" p9 O+ W) `, o9 P6 [! N6 P

# [7 _4 z0 x: Z% u4 l# l函数名: random 7 S$ {0 u6 k: f2 |% y% W
功能: 随机数发生器 " D1 v: S' y" y7 r
用法: int random(int num);
3 h3 k: R$ \. C; d# E3 |# w程序例: ) r x, |9 Z! k% d, n9 k- ?
#include <STDLIB.H>6 n- J' H. b% n0 D' E* `* m3 y8 E0 J
#include <STDIO.H>/ |' U1 O. j" `4 X( |) ?# \6 {
#include <TIME.H>
2 u5 k9 H" \7 t2 t/* prints a random number in the range 0 to 99 */ R# S7 i) E) s: L* V8 S7 V# t
int main(void)
' o: h0 y% u3 l: d4 O{ & z6 w2 \1 a2 N& x8 N" H
randomize();
6 X8 Q. z4 P/ }printf("Random number in the 0-99 range: %d\n", random (100));
/ m2 {6 g: L, q; e, J6 \+ ~return 0; ' Q! f0 w) j x* g7 |- Q: r) k: W
}
/ f5 |8 |) i2 ?, f( e; X: ~
* ?+ ]1 V& V* @$ B$ P V- R. S# U7 u. d9 m" w# }9 p
函数名: randomize 6 H$ V/ I4 q( W7 c, [$ v
功能: 初始化随机数发生器 ) I& S" \$ B6 Q6 E( [
用法: void randomize(void); 0 ~" p/ k( J. K8 a. l
程序例: 
! G' t0 r5 K3 K7 H% I8 j#include <STDLIB.H>
5 f, `6 T5 {+ }5 _2 Y' L& D#include <STDIO.H> A" w7 Q2 G, F) |/ [
#include <TIME.H>
& ^4 p$ R' p4 \- u4 f+ W Iint main(void)
0 q3 v; u- o( }7 { P5 G& c$ Z& D{
: V, C; z& o+ m& H1 y rint i; ; `4 i3 }* a* V3 T5 r* `
randomize();
0 p: m& a. A% {. z0 L* Iprintf("Ten random numbers from 0 to 99\n\n"); 0 ?( ?. w" {3 ~$ ]
for(i=0; i<10; i++)
- i. o4 E* H, vprintf("%d\n", rand() % 100); 9 E, q3 O) j! n- [" I @' {
return 0;
2 z6 R5 H: ]$ o7 B: S. M5 D}
7 ?8 p" D3 N, h* N& M+ Y& c' @8 _1 W& Y
0 G! K* }2 A5 U
函数名: read & W6 ~& K# T; R1 I4 f
功能: 从文件中读
2 ]0 T$ G+ s& n4 k4 H1 y) C. ?! i用法: int read(int handle, void *buf, int nbyte); ' Y8 ]: C9 v; L3 S
程序例: 
4 N+ e& A% _, n, f#include <STDIO.H>6 q' [) d! [/ O) J& x- @2 J- k( m
#include <IO.H># }( T3 I) S a1 v2 I
#include <ALLOC.H>
9 E& Y% d$ c8 [% O+ u) P5 m#include <FCNTL.H>: A* L4 t" j) ?& p. W( c* @
#include <PROCESS.H>
, x( o, O5 s6 I7 t1 |% M/ J#include <SYS\STAT.H># {" K! W, ]7 m! ]1 z
int main(void)
$ a& X) Z* b p* I{
0 P* Z8 T7 C5 ~) l! Avoid *buf; 7 Q8 P9 ?: d3 M; |
int handle, bytes; }: {4 p z3 W3 K3 Z0 [3 n
buf = malloc(10); % m( ]- `+ B Z8 c; W: J' X% k
/*
- E Z' ]& ~2 }; j7 nLooks for a file in the current directory named TEST.$$$ and attempts $ K8 @5 J& b! I! y* O; l' {# J H% M2 s
to read 10 bytes from it. To use this example you should create the
8 M' ^3 f5 c) F' `8 Bfile TEST.$$$
7 O0 f# H" E' K# C5 `7 b% V*/ ' ?' C2 y" }, N3 Z J
if ((handle = - U& W* x- s( m8 j- s0 d
open("TEST.$$$", O_RDONLY | O_BINARY, S_IWRITE | S_IREAD)) == -1) 7 ]7 I% P; Q) H. s, d
{ ' m& ~- M; y8 X4 T9 v& K0 @6 w$ j& Y
printf("Error Opening File\n"); * u. A/ P; I2 w) z
exit(1);
: V" S& u& o# I6 Y& A5 @} 
 u$ V" V" V: a' ^' m1 Jif ((bytes = read(handle, buf, 10)) == -1) { 8 z8 y0 {. b Q3 S
printf("Read Failed.\n"); ; ~# \0 U( v6 y" C9 ]
exit(1);
) {/ G o# ]" F) K; L* T}
. ?8 j( i$ F$ Q) D# p% S7 j$ celse {
3 @, }- t0 D$ M* O& ?2 l* _printf("Read: %d bytes read.\n", bytes); 3 t, L" u( U4 z( L: I) u
}
# C: h* U, R, H* t8 a7 C+ Z! creturn 0; 8 l2 R4 z- P% q# \& R
} 3 r& ^% d( `) O# m2 e

' @$ O' I5 @+ E3 H6 n& z6 l4 `! V; Y& ^& M9 K6 ]) T* Q' J8 Q8 v2 x
函数名: realloc 
1 N$ @# b6 Y. B0 `3 [; a功能: 重新分配主存
! I& p- m( U3 S" g5 `用法: void *realloc(void *ptr, unsigned newsize); . o$ Z0 s U! P3 q
程序例: 
" e O* P4 X9 e: D0 Q y#include <STDIO.H>
' d8 W+ Y' X b" f% m/ u w#include <ALLOC.H>8 H* B! [% `+ ~2 Z- G$ P
#include <STRING.H>
( V A( y- l1 l5 cint main(void) 2 w6 a# l5 L' ^% K
{ 5 @% H9 H0 |9 A* Q# o# q$ O) k
char *str; 
* T7 H. I7 F* c2 Q/* allocate memory for string */
" i) M' O/ L1 a& c* ?str = malloc(10); & M. r" d0 P# M. K" Q- t$ g& L; @9 @
/* copy "Hello" into string */ , b9 Q: T8 e! |
strcpy(str, "Hello"); : o$ p& |1 Y. S- s2 i3 t/ j
printf("String is %s\n Address is %p\n", str, str); 9 E& j# a3 Q @6 J; a0 y
str = realloc(str, 20); ( ?# G# }. b, p/ M2 l
printf("String is %s\n New address is %p\n", str, str); ' } }5 M8 J+ ^0 v; A
/* free memory */ + v5 Z" m+ I. L4 a5 x
free(str); 8 T l5 R# S7 T6 {3 @0 {
return 0; % w3 E. n6 k$ O! K3 X
} n1 b% b$ x' b; ^$ D" Y- N
1 U( v* e5 J; t5 D7 E8 Z
2 w6 i+ O# h. Z' N; r0 R- n: r
函数名: rectangle ) {2 i* |2 V8 Z- n/ v/ N
功能: 画一个矩形
5 K. p# c& O& Q1 b用法: void far rectangle(int left, int top, int right, int bottom);
7 \* n9 B# |2 q1 p程序例: 
; g3 W; t2 x" `6 k, N+ Q+ Q#include <GRAPHICS.H>
( R) U# X: A% K0 t$ t* v#include <STDLIB.H>
3 x$ V7 z1 ]1 A5 |1 }3 `; \#include <STDIO.H>
6 ?- {$ f8 f0 ]7 x#include <CONIO.H>% g3 c9 _- d* W5 I
int main(void)
9 X( U+ T% t2 A{
. N" h, E% l9 d/* request auto detection */ " a# x6 l2 g o5 P+ B
int gdriver = DETECT, gmode, errorcode;
5 z% m. |5 Q9 Y8 B& ]int left, top, right, bottom; 
5 G% i2 @: z7 I/* initialize graphics and local variables */ 0 t2 k8 P$ ^, d6 }* F, }
initgraph(&gdriver, &gmode, ""); 
* J! t. _2 k; S" O, Y4 n; k/* read result of initialization */
1 z) I- J& i, I2 {* I lerrorcode = graphresult();
5 N+ S, C3 l1 E9 Q% n2 j/ Kif (errorcode != grOk) /* an error occurred */
 w s% X1 x1 {{
5 Y% m8 }# T2 Z; g3 u9 w) Qprintf("Graphics error: %s\n", grapherrormsg(errorcode)); 7 i1 b- O1 M" K- `* T& a/ j8 `2 L
printf("Press any key to halt:");
+ ?0 J5 b3 V$ w1 _% ~getch();
, ]% q- S5 m: mexit(1); /* terminate with an error code */
) w* M/ J8 M$ u9 q/ C6 R3 E. P p} 
6 c4 K' K! c! d" L; z! }left = getmaxx() / 2 - 50; ; L, e1 P u$ u k1 I. p. V; z
top = getmaxy() / 2 - 50; ; f1 L7 b! n1 _" `9 {
right = getmaxx() / 2 + 50;
. G* X( A3 y* ~! Jbottom = getmaxy() / 2 + 50; 
: G; A4 v8 i$ a7 r) Z9 a: V) i$ Q/* draw a rectangle */ ' }, P! g5 V( m; F8 \. t
rectangle(left,top,right,bottom); 0 A0 C' d M' z
/* clean up */ 0 K1 m2 `- A- p8 u
getch();
! B& |8 S* S( D# j1 |closegraph(); 8 V$ x+ e m' @* s+ {" h/ G* c
return 0; + r8 N& ]% Z8 j6 [% P
}
) F9 u9 i$ s2 C7 ^
3 A o8 j) d" T) I
* O1 t# b0 x8 M: k9 |+ H1 H# j函数名: registerbgidriver 
$ P9 g o" Y/ S0 l6 S功能: 登录已连接进来的图形驱动程序代码 ' a% ?2 G9 P, y
用法: int registerbgidriver(void(*driver)(void)); $ D* g) D, x+ b
程序例: 
" F% }2 L; p" J$ \1 E#include <GRAPHICS.H>$ E s# j8 E+ o5 h% Q$ z8 O; s2 n
#include <STDLIB.H>! c% O, K5 z! `# [' }% c$ J7 V
#include <STDIO.H>8 L1 R' v% ~$ p X( a
#include <CONIO.H>
$ n2 S; B2 m/ u9 C) Nint main(void) g# j' z% Z0 I0 S
{ 3 N) E' i4 |: E0 x
/* request auto detection */ ! w# B% $ X% J% R
int gdriver = DETECT, gmode, errorcode; $ m# U% b ]6 n3 B" v+ f0 ]
/* register a driver that was added into graphics.lib */ 0 j) `0 v) r) s1 a& ^
errorcode = registerbgidriver(EGAVGA_driver); 2 _9 b$ O( D0 [5 A B8 k" r( p4 O" U
/* report any registration errors */ # k* c" {. t) \. N/ V4 s& [9 h
if (errorcode < 0) 5 i3 ?# c2 t L4 R+ I
{
# h$ A, h- s, \ z$ `/ rprintf("Graphics error: %s\n", grapherrormsg(errorcode)); 8 A0 m. n" ~* u' i+ L+ F
printf("Press any key to halt:"); ! F! g+ g# n( |& p; n9 Z
getch();
$ c" p. f( M6 B$ l, Texit(1); /* terminate with an error code */ ( F+ G' I6 k+ M5 [
} 
- N! C- }) F* M/* initialize graphics and local variables */
+ j8 n$ a' O' F2 qinitgraph(&gdriver, &gmode, ""); 5 l! B5 ~) z& Z* a. Z7 Y4 r% x4 D
/* read result of initialization */
) X$ {0 d9 F& U" @errorcode = graphresult();
- z; D9 }3 T2 G+ i2 A1 G2 B' l! oif (errorcode != grOk) /* an error occurred */ ! ?7 ~3 s0 `) u+ k, \
{
$ f. \ |* m' | E( P+ ?printf("Graphics error: %s\n", grapherrormsg(errorcode));
# _' y7 a, }, \% ?4 L- {printf("Press any key to halt:");
! [" p4 c8 |0 H+ F7 ~8 _getch(); % B z5 d2 o0 ?+ z: e( `
exit(1); /* terminate with an error code */
* E# Q) f, U5 U# o! f} 
! `4 O+ L8 D2 @/* draw a line */
6 N. ^+ D9 G5 b' v7 j, r5 }line(0, 0, getmaxx(), getmaxy()); ' n; |3 T. M' k# H
/* clean up */ , R$ U" {3 D8 N( h, z! w( A. j
getch(); s3 R, t' B# b& O
closegraph(); 2 l/ Y9 o- e1 Z7 d# s' r
return 0;
* a! d. d. g! |. F; O" X7 m}
9 N$ Q" `4 R- S' m2 @+ g8 T6 Z
6 p+ s" M* s/ S- `( w5 Z5 G6 v. u
函数名: remove 
; L; a3 o5 x, @* m: h' Q功能: 删除一个文件 3 ~% b/ f% j# Y, b5 `# }
用法: int remove(char *filename); $ G+ x5 A% C! R- A' {
程序例: 
$ _9 S7 x( w& O4 [$ _#include <STDIO.H>$ S# V. U1 H1 a6 V" {5 T
int main(void)
" M: k+ Y+ Y5 b$ Q- d2 `3 ]{ H3 L: F7 e% @0 m2 }1 K
char file[80]; ( k% E! U0 r( b/ ]* n8 @
/* prompt for file name to delete */ ) C& j- F" R+ T8 I8 u
printf("File to delete: "); 4 L: N4 Q$ n/ q e( @; \# i5 T
gets(file); 
: [1 |8 W8 ^8 v1 X/* delete the file */
" w7 v7 ]- o) y% ] J$ N7 _if (remove(file) == 0)
3 s f( z/ r8 d; s/ |; o+ P7 D' cprintf("Removed %s.\n",file); 9 Y3 J( {# s% W M! `
else
8 M2 H- D' j8 q4 d1 _8 z8 Jperror("remove"); ; C' _* V# y3 c- L
return 0;
! P5 |" r- G5 B( H3 k' _9 Q! N" p} - `6 j( E7 t3 u5 ]$ q

( @0 \/ H$ ?8 u8 h
) D# ^" r9 S. z ?* ^" V函数名: rename ; ~2 u, T% C& Z2 L, j- z0 J' f. [
功能: 重命名文件
6 n1 _5 f& P0 s* z7 Y用法: int rename(char *oldname, char *newname);
9 w, I% W( F G. P0 n2 u. C程序例: & O! f; ]; i0 ]0 j$ Z! W+ ?% d
#include <STDIO.H>
, M4 z: o; t6 J) fint main(void)
% W5 E5 p+ }& O3 L' w) x$ D: Y& o{ / v: Q$ ]( o9 ]* V" z+ r
char oldname[80], newname[80]; 
# F: s. H$ v; H+ j: N5 q; |% U& V6 P/* prompt for file to rename and new name */ ) f) n1 u9 o6 q/ l9 V
printf("File to rename: ");
2 G* G! s: R+ O, [* l: ygets(oldname);
5 I$ O1 z. Y" t$ v iprintf("New name: ");
: e/ L6 J% p% r6 K8 Xgets(newname); 
" t6 d/ s1 \" [5 ] Q$ p/* Rename the file */ . b# t4 i6 V* i$ A% Y. D6 h$ H
if (rename(oldname, newname) == 0)
$ P5 t1 Z) Q* ~( W5 ]+ P9 r* pprintf("Renamed %s to %s.\n", oldname, newname); % b& C1 n- ?8 m
else
( P. [. i% m" \5 Tperror("rename"); 2 Z+ u! U8 D- U' d
return 0;
# ]1 o s |1 v0 B}
0 ^2 _& ?- r8 K& j# q6 {9 A/ w$ O# @

0 b. X, \- u) @6 Y% n" U0 g" r函数名: restorecrtmode 
6 D# R' D5 ~! ]* T' G8 o- X功能: 将屏幕模式恢复为先前的imitgraph设置 f" @9 ~% m% u0 H& l# } i
用法: void far restorecrtmode(void); ) ?8 a7 g4 i/ O7 F- t
程序例: * x" _# l& t$ {7 r8 j1 J
#include <GRAPHICS.H>
8 T, `& c+ ^0 \ f; }#include <STDLIB.H>& q% V: O2 d+ L' k* A* p
#include <STDIO.H>
( ~, G: y7 R D% {0 o6 l# i( W* t. w#include <CONIO.H>
' o& l! o5 R( ?/ a, hint main(void)
' c9 {: a/ e; V{
% G* [+ l' m/ I4 r' Y+ x/* request auto detection */ $ O: {' A' z7 {* X+ m& t
int gdriver = DETECT, gmode, errorcode;
& a2 A/ a! z ]. @int x, y; 
$ C9 ~- P8 n! |4 W6 J6 Y: o0 S/* initialize graphics and local variables */
. W) a9 |: Z Y- U) a; zinitgraph(&gdriver, &gmode, ""); 
3 N' Q% _$ A( |4 f1 G7 j/* read result of initialization */ 4 r* D2 T- K3 H- o( o6 z
errorcode = graphresult(); 8 A5 N, [5 F# W. s! K% |
if (errorcode != grOk) /* an error occurred */ % S/ Y' F7 |) B+ f, A h+ `
{
) Y" I) W+ ]" O. V0 fprintf("Graphics error: %s\n", grapherrormsg(errorcode));
: O$ d& Z) C: v! k, Wprintf("Press any key to halt:"); 9 _, o* r4 Y4 _, K4 q9 h
getch();
" r& K1 D' G: t- uexit(1); /* terminate with an error code */ : D8 M7 Y; S' Y) J/ u# j. n
} / i+ B( G& ~3 e* S% {% J4 _
x = getmaxx() / 2; * q a e3 e5 i
y = getmaxy() / 2; 
7 P$ O+ a7 z6 z0 S/* output a message */
settextjustify(CENTER_TEXT, CENTER_TEXT);
/ ]; T3 h4 g$ \6 w; f- xouttextxy(x, y, "Press any key to exit graphics:");
7 g3 J! @; g3 ]# l1 Agetch(); 4 z. p. i+ s; m
/* restore system to text mode */ % U. e! I5 h, j& G/ ]! }
restorecrtmode();
) {- ?5 K$ Q8 `printf("We're now in text mode.\n");
& x! b1 y3 @4 g' B& Jprintf("Press any key to return to graphics mode:"); 4 ]4 d2 E* T. j' @/ E
getch(); 4 U3 k8 D) _3 _8 ^- D9 ?; Y1 H
/* return to graphics mode */
; u( n3 M. t% S0 [4 y; H; Ssetgraphmode(getgraphmode()); 
: Z% j5 Q% p* ?/* output a message */ K, _0 m- ?+ P- l( k
settextjustify(CENTER_TEXT, CENTER_TEXT);
1 Y1 k: C9 y0 uouttextxy(x, y, "We're back in graphics mode."); , x) k. R; k% A7 ]4 B% Q) E
outtextxy(x, y+textheight("W"), "Press any key to halt:"); . q5 V4 G$ o- y
/* clean up */ ' P2 M$ t; q; e" ~6 N* X
getch();
7 j% S7 G1 r2 xclosegraph(); " {; v. j7 `, I' i- |1 c
return 0; ! j# G `( @* X* d4 n, r: d
} 8 Y1 U R) D8 M( d H$ O* g

7 ^% J5 @0 m7 ^3 ^* |$ r; _% e2 J+ ^% p' m
函数名: rewind 0 w% J+ d! ?/ T$ t) h
功能: 将文件指针重新指向一个流的开头 , Z3 f) ]) d7 w' a& o* F
用法: int rewind(FILE *stream);
" t3 A/ o! }& g9 R4 V# U) V程序例: 
4 W6 N6 ]$ E8 y& r#include <STDIO.H>
7 o; x# d( O; c8 ~2 f4 a7 B& x# ]#include <DIR.H>' q4 s0 f1 B3 w; c" P/ r+ P
int main(void)
; ?1 u: M; h, b! a0 t{
" {) X- g) ?9 B$ P0 U. B& P9 z& nFILE *fp;
2 h9 }" A* h' @# v% Lchar *fname = "TXXXXXX", *newname, first; 
, `2 ]/ l4 W( u. inewname = mktemp(fname);
6 Y6 }9 i$ i {8 N5 Y5 Rfp = fopen(newname,"w+");
9 B( ^) X0 ?# O, }fprintf(fp,"abcdefghijklmnopqrstuvwxyz"); # R# h$ w" w' F( F, @5 _. O
rewind(fp);
 W' q2 c2 ]4 T! r- Zfscanf(fp,"%c",&first); * }2 v1 R) F# T! r
printf("The first character is: %c\n",first); 9 T/ Q, O2 @' o" V ~. t1 r
fclose(fp);
 s& r$ k1 n# G, Lremove(newname); ! E' ]; a8 v3 ^3 a; G
return 0; - t+ K/ x# H5 S! U% u' _/ g
}
+ ?6 ]8 k. f, ^9 ~5 A6 [! U* w6 }
; c$ n! z# w# l0 v
0 B. \: a$ T% w3 R) a6 n) N" j函数名: rmdir : d+ X! N$ @) i/ A$ B5 l
功能: 删除DOS文件目录
7 [* n! L, ~7 B8 J3 M/ D+ m# i用法: int rmdir(char *stream);
程序例: - X; h. e2 k' R4 ^. w' N, j
#include <STDIO.H>
+ y7 O) V$ l1 _$ ~* l: T) u/ r. x#include <CONIO.H>6 |/ Y$ e8 k( |6 Z1 Z
#include <PROCESS.H>: j, M* v; l4 c$ e- [" V* k; ]# V5 Q
#include <DIR.H>. D, I1 ]2 k0 S r# F
#define DIRNAME "testdir.$$$" 
/ E+ z3 [. u' g4 N8 p& sint main(void) " ^6 i7 z/ o. y3 r+ s
{
1 ?7 {2 Z: f) M, O8 r+ [8 kint stat; 
- r5 j# A4 f7 Ystat = mkdir(DIRNAME); 0 q1 |. p6 k( W1 h2 ]) s
if (!stat) 6 y( W$ F3 I k& y' e; \
printf("Directory created\n");
. w( _# ^3 O: c6 Oelse
' k! E2 c) G7 w+ @6 m{ : j7 e8 ]( w: a1 f. U9 f
printf("Unable to create directory\n");
- @; h7 c8 h" g5 l9 Xexit(1);
9 x g k7 Y& T/ F} 
* C, ]6 h3 R1 I' I' g0 o' tgetch(); / }, J4 u3 U/ |; n: J4 y/ q
system("dir/p");
8 q, I3 U# ^" R5 _getch(); & ]- ^: q+ t/ b
stat = rmdir(DIRNAME); 7 p3 _4 O( B, }: v2 ?# p
if (!stat)
! x* Q- u: p9 S8 F! Jprintf("\nDirectory deleted\n");
3 ], z8 p2 ~ M: T- pelse
/ k8 D2 o( }' J1 @$ B6 N2 U{
$ h% `- n% d8 Z* M7 e" _8 Sperror("\nUnable to delete directory\n"); : |0 k! M1 y* G. q* W. M
exit(1);
: j E5 V8 j, B/ F8 m! ~# i} 
: R9 ~- \* G# preturn 0;
1 i9 E6 I0 ?+ s1 o}