fseek函数c语言

C中的fseek()函数 (fseek() function in C)

Prototype:

原型：

    int feek(FILE *stream, long int offset, int origin);

Parameters:

参数：

    FILE *stream, long int offset, int origin

Return type: int

返回类型： int

Use of function:

使用功能：

The fseek() function is used to set the file indicator pointer to the associate with the file stream according to the value of offset and starting point of the file. The prototype of the function fseek() is:

fseek()函数用于根据文件的偏移量和起点将文件指示符指针设置为与文件流相关联。 函数fseek()的原型为：

    int feek(FILE *stream, long int offset, int origin);

Here, the offset is number of bytes from the origin.

在这里， 偏移量是从原点起的字节数。

There are three macros in fseek() function:

fseek()函数中包含三个宏：

1. SEEK_SET: Seek from start of file

   SEEK_SET：从文件开头查找

2. SEEK_CUR: Seek from current location

   SEEK_CUR：从当前位置寻求

3. SEEK_END: Seek from end of file

   SEEK_END：从文件末尾查找

C语言中的fseek()示例 (fseek() example in C)

#include <stdio.h>
#include <stdlib.h>
int main(){//Initialize the file pointer
FILE *f;
//Take a array of characters
char ch[100];
//Create the file for write operation
f=fopen("includehelp.txt","w");
printf("Enter five strings\n");
for(int i=0;i<4;i++){//take the strings from the users
scanf("%[^\n]",&ch);
//write back to the file
fputs(ch,f);
//every time take a new line for the new entry string
//except for last entry.Otherwise print the last line twice
fputs("\n",f);
//clear the stdin stream buffer
fflush(stdin);
}
//take the strings from the users
scanf("%[^\n]",&ch);
fputs(ch,f);
//close the file after write operation is over
fclose(f);
//open a file
f=fopen("includehelp.txt","r");
printf("\n...............print the strings..............\n");
while(!feof(f)){//takes the first 100 character in the character array
fgets(ch,100,f);
//and print the strings
printf("%s",ch);
}
rewind(f);
printf("\n...............print the position before print a strings S..............\n");
fseek(f,0,SEEK_SET);
printf("the file indicator position is - %d\n",ftell(f));
printf("\n...............print the position after print a strings ..............\n");
fgets(ch,100,f);
printf("%s",ch);
fseek(f,0,SEEK_CUR);
//print the current location
printf("the file indicator position is - %d\n",ftell(f));
printf("\n...............print the position after print all the strings ..............\n");
fseek(f,0,SEEK_END);
printf("the file indicator position is - %d\n",ftell(f));
//close the file
fclose(f);
return 0;
}

Output

输出量

翻译自: https://www.includehelp.com/c-programs/fseek-function-in-c-language-with-example.aspx

fseek函数c语言