chap8.lst

Borland C++ Builder The Complete Reference 例程源代码

listing 1
/* Case Switcher */ 
#include <conio.h> 
#include <stdio.h> 
#include <ctype.h> 
 
int main(void) { 
  char ch; 
 
  do { 
    ch = getche(); 
    if(islower(ch)) putchar(toupper(ch)); 
    else putchar(tolower(ch)); 
  } while (ch!='.'); /* use a period to stop*/ 
  return 0; 
}

listing 2
/* This program appears to act as a command-prompt gone wild. It 
   displays the command prompt but displays every character 
   the user types as the next letter in the alphabet. 
*/ 
 
#include <stdio.h> 
#include <conio.h> 
 
int main(void) 
{ 
  char ch; 
 
  do { 
    printf("C>"); 
    for(;;) { 
      ch = getch(); /* read chars without echo */ 
      if(ch=='\r' || ch==1) { 
        printf("\n"); 
        break; 
      } 
      putchar(ch+1); 
    } 
  } while(ch!=1) ; /* exit on control-A */ 
 
  return 0; 
}

listing 3
#include <stdio.h> 
#include <string.h> 
 
int main(void) 
{ 
  char str[80]; 
 
  gets(str); 
  printf("Length is %d", strlen(str)); 
 
  return 0; 
}

listing 4
puts("hello");

listing 5
printf("Hi %c %d %s", 'c', 10, "there!");

listing 6
#include <stdio.h> 
 
int main(void) 
{ 
  double f; 
 
  for(f=1.0; f<1.0e+10; f=f*10) 
    printf("%g ", f); 
 
  return 0; 
}

listing 7
#include <stdio.h> 
 
int main(void) 
{ 
  unsigned num; 
 
  for(num=0; num<=16; num++) { 
    printf("%d ", num);   /* Integer */ 
    printf("%o ", num);   /* Octal */ 
    printf("%x ", num);   /* Hexidecimal - lowercase */ 
    printf("%X\n", num);  /* Hexidecimal - uppercase */ 
  } 
 
  return 0; 
}

listing 8
#include <stdio.h> 
 
int sample; 
 
int main(void) 
{ 
  printf("%p", &sample); 
 
  return 0; 
}

listing 9
#include <stdio.h> 
 
int main(void) 
{ 
  int count; 
 
  printf("this%n is a test\n", &count); 
  printf("%d", count); 
 
  return 0; 
}

listing 10
#include <stdio.h> 
 
int main(void) 
{ 
  double item; 
 
  item = 10.12304; 
 
  printf("%f\n", item); 
  printf("%10f\n", item); 
  printf("%012f\n", item); 
 
  return 0; 
}

listing 11
#include <stdio.h> 
 
int main(void) 
{ 
  int i; 
 
  /* display a table of squares and cubes */ 
  for(i=1; i<20; i++) 
    printf("%8d %8d %8d\n", i, i*i, i*i*i); 
 
  return 0; 
}

listing 12
#include <stdio.h> 
 
int main(void) 
{ 
  printf("%.4f\n", 123.1234567); 
  printf("%3.8d\n", 1000); 
  printf("%10.15s\n", "This is a simple test."); 
 
  return 0; 
}

listing 13
#include <stdio.h> 
 
int main(void) 
{ 
  printf("........................\n"); 
  printf("right-justified:%8d\n", 100); 
  printf("left-justified:%-8d\n", 100); 
 
  return 0; 
}

listing 14
#include <stdio.h> 
 
int main(void) 
{ 
  printf("%x %#x\n", 10, 10); 
  printf("%*.*f", 10, 4, 123.3); 
 
  return 0; 
}

listing 15
#include <stdio.h> 
 
int main(void) 
{ 
  int i, j; 
 
  scanf("%o%x", &i, &j); 
  printf("%o %x", i, j); 
 
  return 0; 
}

listing 16
unsigned num; 
scanf("%u", &num);

listing 17
scanf("%c%c%c", &a, &b, &c);

listing 18
#include <stdio.h> 
 
int main(void) 
{ 
  char str[80]; 
 
  printf("Enter a string: "); 
  scanf("%s", str); 
  printf("Here's your string: %s", str); 
 
  return 0; 
}

listing 19
#include <stdio.h> 
 
int main(void) 
{ 
  char *p; 
 
  printf("Enter an address: "); 
  scanf("%p", &p); 
  printf("Value at location %p is %c\n", p, *p); 
 
  return 0; 
}

listing 20
%[XYZ]

listing 21
#include <stdio.h> 
 
int main(void) 
{ 
  int i; 
  char str[80], str2[80]; 
 
  scanf("%d%[abcdefg]%s", &i, str, str2); 
  printf("%d %s %s", i, str, str2); 
 
  return 0; 
}

listing 22
%[A-Z]

listing 23
/* A scanset example using ranges. */ 
#include <stdio.h> 
 
int main(void) 
{ 
  char s1[80], s2[80]; 
 
  printf("Enter numbers, then some letters"); 
  scanf("%[0-9]%[a-zA-Z]", s1, s2); 
  printf("%s %s", s1, s2); 
 
  return 0; 
}

listing 24
/* A scanset example using inverted ranges. */ 
#include <stdio.h> 
 
int main(void) 
{ 
  char s1[80], s2[80]; 
 
  printf("Enter non-numbers, then some non-letters"); 
  scanf("%[^0-9]%[^a-zA-Z]", s1, s2); 
  printf("%s %s", s1, s2); 
 
  return 0; 
}

listing 25
scanf("%d", &count);

listing 26
scanf("%s", str);

listing 27
scanf("%20s", str);

listing 28
scanf("%s", str2);

listing 29
scanf("%d%*c%d", &x, &y);

listing 30
FILE *fp;

listing 31
FILE *fp; 
fp = fopen("test", "w");

listing 32
FILE *fp; 
if((fp = fopen("test", "w"))==NULL) { 
  printf("Cannot open file.\n"); 
  exit(1); 
}

listing 33
 
do { 
   ch = getc(fp); 
} while(ch!=EOF);

listing 34
/* KTOD: A key to disk program. */ 
 
#include <stdio.h> 
#include <stdlib.h> 
 
int main(int argc, char *argv[]) 
{ 
  FILE *fp; 
  char ch; 
 
  if(argc!=2) { 
    printf("You forgot to enter the filename.\n"); 
    exit(1); 
  } 
 
  if((fp=fopen(argv[1], "w")) == NULL) { 
    printf("Cannot open file.\n"); 
    exit(1); 
  } 
 
  do { 
    ch = getchar(); 
    putc(ch, fp); 
  } while (ch != '$'); 
 
  fclose(fp); 
 
  return 0; 
}

listing 35
/* DTOS: A program that reads text files 
         and displays them on the screen. */ 
#include <stdio.h> 
#include <stdlib.h> 
 
int main(int argc, char *argv[]) 
{ 
  FILE *fp; 
  char ch; 
 
  if(argc!=2) { 
    printf("You forgot to enter the filename.\n"); 
    exit(1); 
  } 
 
  if((fp=fopen(argv[1], "r")) == NULL) { 
    printf("Cannot open file.\n"); 
    exit(1); 
  } 
 
  ch = getc(fp);   /* read one character */ 
 
  while (ch!=EOF) { 
    putchar(ch);  /* print on screen */ 
    ch = getc(fp); 
  } 
 
  fclose(fp); 
 
  return 0; 
}

listing 36
while(!feof(fp)) ch = getc(fp);

listing 37
/* This program will copy a file to another. */ 
#include <stdio.h> 
#include <stdlib.h> 
 
int main(int argc, char *argv[]) 
{ 
  FILE *in, *out; 
  char ch; 
 
  if(argc!=3) { 
    printf("You forgot to enter a filename.\n"); 
    exit(1); 
  } 
 
  if((in=fopen(argv[1], "rb")) == NULL) { 
    printf("Cannot open source file.\n"); 
    exit(1); 
  } 
  if((out=fopen(argv[2], "wb")) == NULL) { 
    printf("Cannot open destination file.\n"); 
    exit(1); 
  } 
 
  /* This code actually copies the file. */ 
  while(!feof(in)) { 
     ch = getc(in); 
     if(!feof(in)) putc(ch, out); 
  } 
 
  fclose(in); 
  fclose(out); 
 
  return 0; 
}

listing 38
#include <stdio.h> 
 
int main(void) 
{ 
  char s[80]; 
 
  printf("Enter a string: "); 
  fgets(s, 80, stdin); 
  printf("Here is your string: %s", s); 
 
  return 0; 
}

listing 39
/* Write a floating point number to a disk file. */ 
#include <stdio.h> 
#include <stdlib.h> 
 
int main(void) 
{ 
  FILE *fp; 
  float f = 12.23; 
 
  if((fp=fopen("test", "wb"))==NULL) { 
    printf("Cannot open file.\n"); 
    exit(1); 
  } 
 
  fwrite(&f, sizeof(float), 1, fp); 
  fclose(fp);
 
  return 0; 
}

listing 40
#include <stdio.h> 
#include <stdlib.h> 
 
int main(void) 
{ 
  register int i; 
  FILE *fp; 
  float balance[100]; 
 
  /* open for write */ 
  if((fp=fopen("balance", "wb"))==NULL) { 
    printf("Cannot open file.\n"); 
    exit(1); 
  } 
 
  for(i=0; i<100; i++) balance[i] = (float) i; 
 
  /* this saves the entire balance array in one step */ 
  fwrite(balance, sizeof balance, 1, fp); 
  fclose(fp); 
 
  /* zero array */ 
  for(i=0; i<100; i++) balance[i] = 0.0; 
 
  /* open for read */ 
  if((fp=fopen("balance","rb"))==NULL) { 
    printf("cannot open file\n"); 
    exit(1); 
  } 
 
  /* this reads the entire balance array in one step */ 
  fread(balance, sizeof balance, 1, fp); 
 
  /* display contents of array */ 
  for(i=0; i<100; i++) printf("%f ", balance[i]); 
 
  fclose(fp); 
  return 0; 
}

listing 41
int func1(void) 
{ 
  FILE *fp; 
 
  if((fp=fopen("test", "rb")) == NULL) { 
    printf("Cannot open file.\n"); 
    exit(1); 
  } 
 
  fseek(fp, 234L, 0); 
  return getc(fp);   /* read one character */ 
                     /* at 234th position */ 
  } 
}

listing 42
/* DUMP: A simple disk look utility using fseek. */ 
#include <stdio.h> 
#include <stdlib.h> 
#include <ctype.h> 
 
#define SIZE 128 
 
void display(int numread); 
 
char buf[SIZE]; 
void display(); 
 
int main(int argc, char *argv[]) 
{ 
  FILE *fp; 
  int sector, numread; 
 
  if(argc!=2) { 
    printf("Usage: dump filename\n"); 
    exit(1); 
  } 
 
  if((fp=fopen(argv[1], "rb"))==NULL) { 
    printf("Cannot open file.\n"); 
    exit(1); 
  } 
 
  do { 
    printf("Enter sector: "); 
    scanf("%d", &sector); 
    if(sector >= 0) { 
      if(fseek(fp, sector*SIZE, SEEK_SET)) { 
        printf("seek error"); 
      } 
      if((numread=fread(buf, 1, SIZE, fp)) != SIZE) 
        printf("EOF reached."); 
 
      display(numread); 
    } 
  } while(sector>=0); 
  return 0; 
} 
 
/* Display the contents of a file. */ 
void display(int numread) 
{ 
  int i, j; 
 
  for(i=0; i<numread/16; i++) { 
    for(j=0; j<16; j++) printf("%3X", buf[i*16+j]); 
    printf("  "); 
    for(j=0; j<16; j++) { 
      if(isprint(buf[i*16+j])) printf("%c", buf[i*16+j]); 
      else printf("."); 
    } 
    printf("\n"); 
  } 
}

listing 43
/* A remove() example. */ 
 
#include <stdio.h> 
#include <stdlib.h> 
 
int main(void) 
{ 
  char fname[80]; 
 
  printf("Name of file to remove: "); 
  gets(fname); 
 
  if(remove(fname)) { 
    printf("Error removing file\n"); 
    exit(1); 
  } 
 
  return 0; 
}

listing 44
int putchar(int c) 
{ 
  return putc(c, stdout); 
}

listing 45
#include <stdio.h> 
 
int main(void) 
{ 
  char str[80]; 
 
  printf("Enter a string: "); 
  gets(str); 
  printf(str); 
 
  return 0; 
}