关于文件操作的C语言问题

[gg882]

这是一个核苷酸配对的程序，我的原文件保存在D：\a.txt 里，我想把翻译后的核苷酸保存在D：\b.txt里，具体应该怎样在下面的程序里面添加啊？谢谢了！
#include <stdio.h>
void main()
{
for (;;)
{
char c = getchar();

if (c == -1)
{
break;
}

if (c == 'A')
{
c = 'T';
}
else if (c == 'T')
{
c = 'A';
}
else if (c == 'C')
{
c = 'G';
}
else if (c == 'G')
{
c = 'C';
}
else
{
fputs("Error input!", stderr);

break;
}

putchar(c);
}
}

[yeah920]

不会,帮up

[太乙]

原文件保存在D：\a.txt 里，翻译后的核苷酸保存在D：\b.txt里

#include <stdio.h> 
#include <file.h>
#include <stdlib.h> 
void main() 
{ 

  FILE* fp = fopen("D:\\a.txt", "r");
  if (NULL == fp)
  {
    return;
  }
  FILE* fp2 = fopen("D:\\b.txt", "w");
  if (NULL == fp2)
  {
    return;
  }
  for (;fp != eof;) 
  { 
    char c = getchar(fp); 

    if (c == -1) 
{ 
      break; 
} 

    if (c == 'A') 
{ 
      c = 'T'; 
} 
    else if (c == 'T') 
{ 
      c = 'A'; 
} 
    else if (c == 'C') 
{ 
      c = 'G'; 
} 
    else if (c == 'G') 
{ 
      c = 'C'; 
} 
    else 
{ 
      fputs("Error input!", stderr); 

      break; 
} 

      putchar(fp2,c); 
  } 
  fclose(fp);
  fclose(fp2);
}

[rabbitlzx]

FILE* pf = fopen( "D:\b.txt", "r+" );
if( pf )
{
char c;
fscanf( pf, "%c", &c ); //read from file
fprintf( pf, "%s", "some thing you want to store.\n" ); //write to file
fclose( pf ); //
}

另外也可以用fwrite fread等api
msdn上的例子
Example

/* FREAD.C: This program opens a file named FREAD.OUT and
* writes 25 characters to the file. It then tries to open
* FREAD.OUT and read in 25 characters. If the attempt succeeds,
* the program displays the number of actual items read.
*/

#include <stdio.h>

void main( void )
{
FILE *stream;
char list[30];
int i, numread, numwritten;

/* Open file in text mode: */
if( (stream = fopen( "fread.out", "w+t" )) != NULL )
{
for ( i = 0; i < 25; i++ )
list[i] = (char)('z' - i);
/* Write 25 characters to stream */
numwritten = fwrite( list, sizeof( char ), 25, stream );
printf( "Wrote %d items\n", numwritten );
fclose( stream );

}
else
printf( "Problem opening the file\n" );

if( (stream = fopen( "fread.out", "r+t" )) != NULL )
{
/* Attempt to read in 25 characters */
numread = fread( list, sizeof( char ), 25, stream );
printf( "Number of items read = %d\n", numread );
printf( "Contents of buffer = %.25s\n", list );
fclose( stream );
}
else
printf( "File could not be opened\n" );
}


Output

Wrote 25 items
Number of items read = 25
Contents of buffer = zyxwvutsrqponmlkjihgfedcb

[lingyin55]

up

[waizqfor]

直接打开文件 然后开始写就OK了

#include <stdio.h>  
void main() 
{ 
FILE* fp = fopen("D:\\a.txt", "r");
  if (NULL == fp)
  {
    return -1;
  }
FILE* fp2 = fopen("D:\\b.txt", "w");
for (;;) 
  { 
    char c = getchar(); 

    if (c == -1) 
{ 
      break; 
} 

    if (c == 'A') 
{ 
      c = 'T'; 
} 
    else if (c == 'T') 
{ 
      c = 'A'; 
} 
    else if (c == 'C') 
{ 
      c = 'G'; 
} 
    else if (c == 'G') 
{ 
      c = 'C'; 
} 
    else 
{ 
      fputs("Error input!", stderr); 

      break; 
} 

      putchar(fp2, c); 
  } 
fclose(fp2);
fclose(fp);//关闭文件

}

[猫已经找不回了]

就是文件打开,读取,写入,关闭几个操作呗,书上都有.
2楼的就可以.