函数名: fsetpos

功 能: 定位流上的文件指针

用 法: int fsetpos(FILE *stream, const fpos_t *pos);

程序例:

#include <stdlib.h>

#include <stdio.h>

void showpos(FILE *stream);

int main(void)

{

FILE *stream;

fpos_t filepos;

/* open a file for update */

stream = fopen("DUMMY.FIL", "w+");

/* save the file pointer position */

fgetpos(stream, &filepos);

/* write some data to the file */

fprintf(stream, "This is a test");

/* show the current file position */

showpos(stream);

/* set a new file position, display it */

if (fsetpos(stream, &filepos) == 0)

showpos(stream);

else

{

fprintf(stderr, "Error setting file \\

pointer.\");

exit(1);

}

/* close the file */

fclose(stream);

return 0;

}

void showpos(FILE *stream)

{

fpos_t pos;

/* display the current file pointer

position of a stream */

fgetpos(stream, &pos);

printf("File position: %ld\", pos);

}