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<BR> <P>函数名: putc<BR>功 能: 输出一字符到指定流中<BR>用 法: int putc(int ch, FILE *stream);<BR>程序例:<P>#include <stdio.h><P>int main(void)<BR>{<BR> char msg[] = "Hello world\n";<BR> int i = 0;<P> while (msg[i])<BR> putc(msg[i++], stdout);<BR> return 0;<BR>}<BR> <BR> <P>函数名: putch<BR>功 能: 输出字符到控制台<BR>用 法: int putch(int ch);<BR>程序例:<P>#include <stdio.h><BR>#include <conio.h><P>int main(void)<BR>{<BR> char ch = 0;<P> printf("Input a string:");<BR> while ((ch != '\r'))<BR> {<BR> ch = getch();<BR> putch(ch);<BR> }<BR> return 0;<BR>}<BR> <BR> <P>函数名: putchar<BR>功 能: 在stdout上输出字符<BR>用 法: int putchar(int ch);<BR>程序例:<P>#include <stdio.h><P>/* define some box-drawing characters */<BR>#define LEFT_TOP 0xDA<BR>#define RIGHT_TOP 0xBF<BR>#define HORIZ 0xC4<BR>#define VERT 0xB3<BR>#define LEFT_BOT 0xC0<BR>#define RIGHT_BOT 0xD9<P>int main(void)<BR>{<BR> char i, j;<P> /* draw the top of the box */<BR> putchar(LEFT_TOP);<BR> for (i=0; i<10; i++)<BR> putchar(HORIZ);<BR> putchar(RIGHT_TOP);<BR> putchar('\n');<P> /* draw the middle */<BR> for (i=0; i<4; i++)<BR> {<BR> putchar(VERT);<BR> for (j=0; j<10; j++)<BR> putchar(' ');<BR> putchar(VERT);<BR> putchar('\n');<BR> }<P> /* draw the bottom */<BR> putchar(LEFT_BOT);<BR> for (i=0; i<10; i++)<BR> putchar(HORIZ);<BR> putchar(RIGHT_BOT);<BR> putchar('\n');<P> return 0;<BR>}<BR> <BR> <P>函数名: putenv<BR>功 能: 把字符串加到当前环境中<BR>用 法: int putenv(char *envvar);<BR>程序例:<P>#include <stdio.h><BR>#include <stdlib.h><BR>#include <alloc.h><BR>#include <string.h><BR>#include <dos.h><P>int main(void)<BR>{<BR> char *path, *ptr;<BR> int i = 0;<P> /* get the current path environment */<BR> ptr = getenv("PATH");<P> /* set up new path */<BR> path = malloc(strlen(ptr)+15);<BR> strcpy(path,"PATH=");<BR> strcat(path,ptr);<BR> strcat(path,";c:\\temp");<P> /* replace the current path and display current environment*/<BR> putenv(path);<BR> while (environ[i])<BR> printf("%s\n",environ[i++]);<P> return 0;<BR>}<BR> <BR> <P>函数名: putimage<BR>功 能: 在屏幕上输出一个位图<BR>用 法: void far putimage(int x, int y, void far *bitmap, intop);<BR>程序例:<P>#include <graphics.h><BR>#include <stdlib.h><BR>#include <stdio.h><BR>#include <conio.h><P>#define ARROW_SIZE 10<P>void draw_arrow(int x, int y);<P>int main(void)<BR>{<BR> /* request autodetection */<BR> int gdriver = DETECT, gmode, errorcode;<BR> void *arrow;<BR> int x, y, maxx;<BR> unsigned int size;<P> /* initialize graphics and local variables */<BR> initgraph(&gdriver, &gmode, "");<P> /* read result of initialization */<BR> errorcode = graphresult();<BR> if (errorcode != grOk) /* an error occurred */<BR> {<BR> printf("Graphics error: %s\n", grapherrormsg(errorcode));<BR> printf("Press any key to halt:");<BR> getch();<BR> exit(1); /* terminate with an errorcode */<BR> }<P> maxx = getmaxx();<BR> x = 0;<BR> y = getmaxy() / 2;<P> /* draw the image to be grabbed */<BR> draw_arrow(x, y);<P> /* calculate the size of the image */<BR> size = imagesize(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE);<P> /* allocate memory to hold the image */<BR> arrow = malloc(size);<P> /* grab the image */<BR> getimage(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE,arrow);<P> /* repeat until a key is pressed */<BR> while (!kbhit())<BR> {<BR> /* erase old image */<BR> putimage(x, y-ARROW_SIZE, arrow, XOR_PUT);<P> x += ARROW_SIZE;<BR> if (x >= maxx)<BR> x = 0;<P> /* plot new image */<BR> putimage(x, y-ARROW_SIZE, arrow, XOR_PUT);<BR> }<P> /* clean up */<BR> free(arrow);<BR> closegraph();<BR> return 0;<BR>}<P>void draw_arrow(int x, int y)<BR>{<BR> /* draw an arrow on the screen */<BR> moveto(x, y);<BR> linerel(4*ARROW_SIZE, 0);<BR> linerel(-2*ARROW_SIZE, -1*ARROW_SIZE);<BR> linerel(0, 2*ARROW_SIZE);<BR> linerel(2*ARROW_SIZE, -1*ARROW_SIZE);<BR>}<BR> <BR> <P>函数名: putpixel<BR>功 能: 在指定位置画一像素<BR>用 法: void far putpixel (int x, int y, int pixelcolor);<BR>程序例:<P>#include <graphics.h><BR>#include <stdlib.h><BR>#include <stdio.h><BR>#include <conio.h><BR>#include <dos.h><P>#define PIXEL_COUNT 1000<BR>#define DELAY_TIME 100 /* in milliseconds */<P>int main(void)<BR>{<BR> /* request autodetection */<BR> int gdriver = DETECT, gmode, errorcode;<BR> int i, x, y, color, maxx, maxy, maxcolor, seed;<P> /* initialize graphics and local variables */<BR> initgraph(&gdriver, &gmode, "");<P> /* read result of initialization */<BR> errorcode = graphresult();<BR> if (errorcode != grOk) /* an error occurred */<BR> {<BR> printf("Graphics error: %s\n", grapherrormsg(errorcode));<BR> printf("Press any key to halt:");<BR> getch();<BR> exit(1); /* terminate with an errorcode */<BR> }<P> maxx = getmaxx() + 1;<BR> maxy = getmaxy() + 1;<BR> maxcolor = getmaxcolor() + 1;<P> while (!kbhit())<BR> {<BR> /* seed the random number generator*/<BR> seed = random(32767);<BR> srand(seed);<BR> for (i=0; i<PIXEL_COUNT; i++)<BR> {<BR> x = random(maxx);<BR> y = random(maxy);<BR> color = random(maxcolor);<BR> putpixel(x, y, color);<BR> }<P> delay(DELAY_TIME);<BR> srand(seed);<BR> for (i=0; i<PIXEL_COUNT; i++)<BR> {<BR> x = random(maxx);<BR> y = random(maxy);<BR> color = random(maxcolor);<BR> if (color == getpixel(x, y))<BR> putpixel(x, y, 0);<BR> }<BR> }<P> /* clean up */<BR> getch();<BR> closegraph();<BR> return 0;<BR>}<BR> <BR> <P>函数名: puts<BR>功 能: 送一字符串到流中<BR>用 法: int puts(char *string);<BR>程序例:<P>#include <stdio.h><BR>int main(void)<BR>{<BR> char string[] = "This is an example output string\n";<P> puts(string);<BR> return 0;<BR>}<BR> <BR> <P>函数名: puttext<BR>功 能: 将文本从存储区拷贝到屏幕<BR>用 法: int puttext(int left, int top, int right, int bottom,void *source);<BR>程序例:<P>#include <conio.h><BR>int main(void)<BR>{<BR> char buffer[512];<P> /* put some text to the console */<BR> clrscr();<BR> gotoxy(20, 12);<BR> cprintf("This is a test. Press any key to continue...");<BR> getch();<P> /* grab screen contents */<BR> gettext(20, 12, 36, 21,buffer);<BR> clrscr();<P> /* put selected characters back to the screen */<BR> gotoxy(20, 12);<BR> puttext(20, 12, 36, 21, buffer);<BR> getch();<P> return 0;<BR>}<BR> <BR> <P>函数名: putw<BR>功 能: 把一字符或字送到流中<BR>用 法: int putw(int w, FILE *stream);<BR>程序例:<P>#include <stdio.h><BR>#include <stdlib.h><P>#define FNAME "test.$$$"<P>int main(void)<BR>{<BR> FILE *fp;<BR> int word;<P> /* place the word in a file */<BR> fp = fopen(FNAME, "wb");<BR> if (fp == NULL)<BR> {<BR> printf("Error opening file %s\n", FNAME);<BR> exit(1);<BR> }<P> word = 94;<BR> putw(word,fp);<BR> if (ferror(fp))<BR> printf("Error writing to file\n");<BR> else<BR> printf("Successful write\n");<BR> fclose(fp);<P> /* reopen the file */<BR> fp = fopen(FNAME, "rb");<BR> if (fp == NULL)<BR> {<BR> printf("Error opening file %s\n", FNAME);<BR> exit(1);<BR> }<P> /* extract the word */<BR> word = getw(fp);<BR> if (ferror(fp))<BR> printf("Error reading file\n");<BR> else<BR> printf("Successful read: word= %d\n", word);<P> /* clean up */<BR> fclose(fp);<BR> unlink(FNAME);<P> return 0;<BR>}<BR> <P> <A HREF="index.html">返回目录</A><BR></BODY></HTML>⌨️ 快捷键说明
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