程序中有時候，我們需要生成多個文件名連續的文件，那麼我們就需要用到函數
int sprintf( char *buffer, const char *format [, argument] ... );
int swprintf( wchar_t *buffer, const wchar_t *format [, argument] ... );
|
Routine |
Required Header |
Compatibility |
|
sprintf |
<stdio.h> |
ANSI, Win 95, Win NT |
|
swprintf |
<stdio.h> or <wchar.h> |
ANSI, Win 95, Win NT |
Libraries
|
LIBC.LIB |
Single thread static library, retail version |
|
LIBCMT.LIB |
Multithread static library, retail version |
|
MSVCRT.LIB |
Import library for MSVCRT.DLL, retail version |
Return Value
sprintf returns the number of bytes stored in buffer, not counting the terminating null character. swprintf returns the number of wide characters stored in buffer, not counting the terminating null wide character.
Parameters
buffer
Storage location for output
format
Format-control string
argument
Optional arguments
/*批量生成文件名爲 Beauty01.txt,Beauty02.txt,Beauty03.txt......
內容寫文件名
*/
#include<stdio.h>
#include<stdlib.h>
int main()
{
unsigned char file_name[15];
unsigned i;
for(i=1;i<=9;i++)
{
sprintf(file_name,"Beauty%02d.txt",i);
freopen(file_name,"wb",stdout);
printf("%s/n",file_name);
}
return 0;
}
讀取文本信息，並且以追加的方式寫入
#include<stdio.h>
#include<stdlib.h>
void isOpenFile(FILE *fp)
{
if(NULL == fp) //打開文件失敗
{
printf("/nError Open the File!/n");
getch();
exit(1);
}
return;
}
int main()
{
FILE *my_file;
my_file = fopen("G://cpp//test.txt","rb");
isOpenFile(my_file);
char ch;
ch = fgetc(my_file);
while((0 == feof(my_file)))
{
putchar(ch);
ch = fgetc(my_file);
}
fclose(my_file); //關閉文件
/************************************************/
my_file = fopen("G://cpp//test.txt","ab+");
isOpenFile(my_file);
int i;
for(i=0;i<100;i++)
{
fputc(i,my_file);
}
rewind(my_file);
ch = fgetc(my_file);
while((0 == feof(my_file)))
{
printf("%d ",ch);
ch = fgetc(my_file);
}
fclose(my_file);
/*************************************************/
putchar(-43); //test
putchar(-30);
return 0;
}
如何獲得未知文件的大小
Moves the file pointer to a specified location.
int fseek( FILE *stream, long offset, int origin );
orgin：
SEEK_CUR
Current position of file pointer
SEEK_END
End of file
SEEK_SET
Beginning of file
Gets the current position of a file pointer.
long ftell( FILE *stream );
Code：
#include<stdio.h>
#include<stdlib.h>
void isOpenFile(FILE *fp)
{
if(NULL == fp) //打開文件失敗
{
printf("/nError Open the File!/n");
getch();
exit(1);
}
return;
}
int main()
{
FILE *my_file;
my_file = fopen("G://cpp//test.txt","rb");
isOpenFile(my_file);
fseek(my_file,0,SEEK_END);
int Length = ftell(my_file);
rewind(my_file);
printf("%d/n",Length);
fclose(my_file);
return 0;
}