函数名: parsfnm 功 能: 分析文件名 用 法: char *parsfnm (char *cmdline, struct fcb *fcbptr, int option); 程序例: #include <process.h> #include <string.h> #include <stdio.h> #include <dos.h> int main(void) { char line[80]; struct fcb blk; /* get file name */ printf("Enter drive and file name (no path - ie. a:file.dat)\n"); gets(line); /* put file name in fcb */ if (parsfnm(line, &blk, 1) == NULL) printf("Error in parsfm call\n"); else printf("Drive #%d Name: %11s\n", blk.fcb_drive, blk.fcb_name); return 0; } 函数名: peek 功 能: 检查存储单元 用 法: int peek(int segment, unsigned offset); 程序例: #include <stdio.h> #include <conio.h> #include <dos.h> int main(void) { int value = 0; printf("The current status of your keyboard is:\n"); value = peek(0x0040, 0x0017); if (value & 1) printf("Right shift on\n"); else printf("Right shift off\n"); if (value & 2) printf("Left shift on\n"); else printf("Left shift off\n"); if (value & 4) printf("Control key on\n"); else printf("Control key off\n"); if (value & 8) printf("Alt key on\n"); else printf("Alt key off\n"); if (value & 16) printf("Scroll lock on\n"); else printf("Scroll lock off\n"); if (value & 32) printf("Num lock on\n"); else printf("Num lock off\n"); if (value & 64) printf("Caps lock on\n"); else printf("Caps lock off\n"); return 0; } 函数名: peekb 功 能: 检查存储单元 用 法: char peekb (int segment, unsigned offset); 程序例: #include <stdio.h> #include <conio.h> #include <dos.h> int main(void) { int value = 0; printf("The current status of your keyboard is:\n"); value = peekb(0x0040, 0x0017); if (value & 1) printf("Right shift on\n"); else printf("Right shift off\n"); if (value & 2) printf("Left shift on\n"); else printf("Left shift off\n"); if (value & 4) printf("Control key on\n"); else printf("Control key off\n"); if (value & 8) printf("Alt key on\n"); else printf("Alt key off\n"); if (value & 16) printf("Scroll lock on\n"); else printf("Scroll lock off\n"); if (value & 32) printf("Num lock on\n"); else printf("Num lock off\n"); if (value & 64) printf("Caps lock on\n"); else printf("Caps lock off\n"); return 0; } 函数名: perror 功 能: 系统错误信息 用 法: void perror(char *string); 程序例: #include <stdio.h> int main(void) { FILE *fp; fp = fopen("perror.dat", "r"); if (!fp) perror("Unable to open file for reading"); return 0; } 函数名: pieslice 功 能: 绘制并填充一个扇形 用 法: void far pieslice(int x, int stanle, int endangle, int radius); 程序例: #include <graphics.h> #include <stdlib.h> #include <stdio.h> #include <conio.h> int main(void) { /* request auto detection */ int gdriver = DETECT, gmode, errorcode; int midx, midy; int stangle = 45, endangle = 135, radius = 100; /* initialize graphics and local variables */ initgraph(&gdriver, &gmode, ""); /* read result of initialization */ errorcode = graphresult(); if (errorcode != grOk) /* an error occurred */ { printf("Graphics error: %s\n", grapherrormsg(errorcode)); printf("Press any key to halt:"); getch(); exit(1); /* terminate with an error code */ } midx = getmaxx() / 2; midy = getmaxy() / 2; /* set fill style and draw a pie slice */ setfillstyle(EMPTY_FILL, getmaxcolor()); pieslice(midx, midy, stangle, endangle, radius); /* clean up */ getch(); closegraph(); return 0; } 函数名: poke 功 能: 存值到一个给定存储单元 用 法: void poke(int segment, int offset, int value); 程序例: #include <dos.h> #include <conio.h> int main(void) { clrscr(); cprintf("Make sure the scroll lock key is off and press any key\r\n"); getch(); poke(0x0000,0x0417,16); cprintf("The scroll lock is now on\r\n"); return 0; } 函数名: pokeb 功 能: 存值到一个给定存储单元 用 法: void pokeb(int segment, int offset, char value); 程序例: #include <dos.h> #include <conio.h> int main(void) { clrscr(); cprintf("Make sure the scroll lock key is off and press any key\r\n"); getch(); pokeb(0x0000,0x0417,16); cprintf("The scroll lock is now on\r\n"); return 0; } 函数名: poly 功 能: 根据参数产生一个多项式 用 法: double poly(double x, int n, double c[]); 程序例: #include <stdio.h> #include <math.h> /* polynomial: x**3 - 2x**2 + 5x - 1 */ int main(void) { double array[] = { -1.0, 5.0, -2.0, 1.0 }; double result; result = poly(2.0, 3, array); printf("The polynomial: x**3 - 2.0x**2 + 5x - 1 at 2.0 is %lf\n", result); return 0; } 函数名: pow 功 能: 指数函数(x的y次方) 用 法: double pow(double x, double y); 程序例: #include <math.h> #include <stdio.h> int main(void) { double x = 2.0, y = 3.0; printf("%lf raised to %lf is %lf\n", x, y, pow(x, y)); return 0; } 函数名: pow10 功 能: 指数函数(10的p次方) 用 法: double pow10(int p); 程序例: #include <math.h> #include <stdio.h> int main(void) { double p = 3.0; printf("Ten raised to %lf is %lf\n", p, pow10(p)); return 0; } 函数名: printf 功 能: 产生格式化输出的函数 用 法: int printf(char *format...); 程序例: #include <stdio.h> #include <string.h> #define I 555 #define R 5.5 int main(void) { int i,j,k,l; char buf[7]; char *prefix = buf; char tp[20]; printf("prefix 6d 6o 8x 10.2e " "10.2f\n"); strcpy(prefix,"%"); for (i = 0; i < 2; i++) { for (j = 0; j < 2; j++) for (k = 0; k < 2; k++) for (l = 0; l < 2; l++) { if (i==0) strcat(prefix,"-"); if (j==0) strcat(prefix,"+"); if (k==0) strcat(prefix,"#"); if (l==0) strcat(prefix,"0"); printf("%5s |",prefix); strcpy(tp,prefix); strcat(tp,"6d |"); printf(tp,I); strcpy(tp,""); strcpy(tp,prefix); strcat(tp,"6o |"); printf(tp,I); strcpy(tp,""); strcpy(tp,prefix); strcat(tp,"8x |"); printf(tp,I); strcpy(tp,""); strcpy(tp,prefix); strcat(tp,"10.2e |"); printf(tp,R); strcpy(tp,prefix); strcat(tp,"10.2f |"); printf(tp,R); printf(" \n"); strcpy(prefix,"%"); } } return 0; } 函数名: putc 功 能: 输出一字符到指定流中 用 法: int putc(int ch, FILE *stream); 程序例: #include <stdio.h> int main(void) { char msg[] = "Hello world\n"; int i = 0; while (msg[i]) putc(msg[i++], stdout); return 0; } 函数名: putch 功 能: 输出字符到控制台 用 法: int putch(int ch); 程序例: #include <stdio.h> #include <conio.h> int main(void) { char ch = 0; printf("Input a string:"); while ((ch != '\r')) { ch = getch(); putch(ch); } return 0; } 函数名: putchar 功 能: 在stdout上输出字符 用 法: int putchar(int ch); 程序例: #include <stdio.h> /* define some box-drawing characters */ #define LEFT_TOP 0xDA #define RIGHT_TOP 0xBF #define HORIZ 0xC4 #define VERT 0xB3 #define LEFT_BOT 0xC0 #define RIGHT_BOT 0xD9 int main(void) { char i, j; /* draw the top of the box */ putchar(LEFT_TOP); for (i=0; i<10; i++) putchar(HORIZ); putchar(RIGHT_TOP); putchar('\n'); /* draw the middle */ for (i=0; i<4; i++) { putchar(VERT); for (j=0; j<10; j++) putchar(' '); putchar(VERT); putchar('\n'); } /* draw the bottom */ putchar(LEFT_BOT); for (i=0; i<10; i++) putchar(HORIZ); putchar(RIGHT_BOT); putchar('\n'); return 0; } 函数名: putenv 功 能: 把字符串加到当前环境中 用 法: int putenv(char *envvar); 程序例: #include <stdio.h> #include <stdlib.h> #include <alloc.h> #include <string.h> #include <dos.h> int main(void) { char *path, *ptr; int i = 0; /* get the current path environment */ ptr = getenv("PATH"); /* set up new path */ path = malloc(strlen(ptr)+15); strcpy(path,"PATH="); strcat(path,ptr); strcat(path,";c:\\temp"); /* replace the current path and display current environment */ putenv(path); while (environ[i]) printf("%s\n",environ[i++]); return 0; } 函数名: putimage 功 能: 在屏幕上输出一个位图 用 法: void far putimage(int x, int y, void far *bitmap, int op); 程序例: #include <graphics.h> #include <stdlib.h> #include <stdio.h> #include <conio.h> #define ARROW_SIZE 10 void draw_arrow(int x, int y); int main(void) { /* request autodetection */ int gdriver = DETECT, gmode, errorcode; void *arrow; int x, y, maxx; unsigned int size; /* initialize graphics and local variables */ initgraph(&gdriver, &gmode, ""); /* read result of initialization */ errorcode = graphresult(); if (errorcode != grOk) /* an error occurred */ { printf("Graphics error: %s\n", grapherrormsg(errorcode)); printf("Press any key to halt:"); getch(); exit(1); /* terminate with an error code */ } maxx = getmaxx(); x = 0; y = getmaxy() / 2; /* draw the image to be grabbed */ draw_arrow(x, y); /* calculate the size of the image */ size = imagesize(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE); /* allocate memory to hold the image */ arrow = malloc(size); /* grab the image */ getimage(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE, arrow); /* repeat until a key is pressed */ while (!kbhit()) { /* erase old image */ putimage(x, y-ARROW_SIZE, arrow, XOR_PUT); x += ARROW_SIZE; if (x >= maxx) x = 0; /* plot new image */ putimage(x, y-ARROW_SIZE, arrow, XOR_PUT); } /* clean up */ free(arrow); closegraph(); return 0; } void draw_arrow(int x, int y) { /* draw an arrow on the screen */ moveto(x, y); linerel(4*ARROW_SIZE, 0); linerel(-2*ARROW_SIZE, -1*ARROW_SIZE); linerel(0, 2*ARROW_SIZE); linerel(2*ARROW_SIZE, -1*ARROW_SIZE); } 函数名: putpixel 功 能: 在指定位置画一像素 用 法: void far putpixel (int x, int y, int pixelcolor); 程序例: #include <graphics.h> #include <stdlib.h> #include <stdio.h> #include <conio.h> #include <dos.h> #define PIXEL_COUNT 1000 #define DELAY_TIME 100 /* in milliseconds */ int main(void) { /* request autodetection */ int gdriver = DETECT, gmode, errorcode; int i, x, y, color, maxx, maxy, maxcolor, seed; /* initialize graphics and local variables */ initgraph(&gdriver, &gmode, ""); /* read result of initialization */ errorcode = graphresult(); if (errorcode != grOk) /* an error occurred */ { printf("Graphics error: %s\n", grapherrormsg(errorcode)); printf("Press any key to halt:"); getch(); exit(1); /* terminate with an error code */ } maxx = getmaxx() + 1; maxy = getmaxy() + 1; maxcolor = getmaxcolor() + 1; while (!kbhit()) { /* seed the random number generator */ seed = random(32767); srand(seed); for (i=0; i<PIXEL_COUNT; i++) { x = random(maxx); y = random(maxy); color = random(maxcolor); putpixel(x, y, color); } delay(DELAY_TIME); srand(seed); for (i=0; i<PIXEL_COUNT; i++) { x = random(maxx); y = random(maxy); color = random(maxcolor); if (color == getpixel(x, y)) putpixel(x, y, 0); } } /* clean up */ getch(); closegraph(); return 0; } 函数名: puts 功 能: 送一字符串到流中 用 法: int puts(char *string); 程序例: #include <stdio.h> int main(void) { char string[] = "This is an example output string\n"; puts(string); return 0; } 函数名: puttext 功 能: 将文本从存储区拷贝到屏幕 用 法: int puttext(int left, int top, int right, int bottom, void *source); 程序例: #include <conio.h> int main(void) { char buffer[512]; /* put some text to the console */ clrscr(); gotoxy(20, 12); cprintf("This is a test. Press any key to continue ..."); getch(); /* grab screen contents */ gettext(20, 12, 36, 21,buffer); clrscr(); /* put selected characters back to the screen */ gotoxy(20, 12); puttext(20, 12, 36, 21, buffer); getch(); return 0; } 函数名: putw 功 能: 把一字符或字送到流中 用 法: int putw(int w, FILE *stream); 程序例: #include <stdio.h> #include <stdlib.h> #define FNAME "test.$$$" int main(void) { FILE *fp; int word; /* place the word in a file */ fp = fopen(FNAME, "wb"); if (fp == NULL) { printf("Error opening file %s\n", FNAME); exit(1); } word = 94; putw(word,fp); if (ferror(fp)) printf("Error writing to file\n"); else printf("Successful write\n"); fclose(fp); /* reopen the file */ fp = fopen(FNAME, "rb"); if (fp == NULL) { printf("Error opening file %s\n", FNAME); exit(1); } /* extract the word */ word = getw(fp); if (ferror(fp)) printf("Error reading file\n"); else printf("Successful read: word = %d\n", word); /* clean up */ fclose(fp); unlink(FNAME); return 0; }