C library function - rewind()

时间:2023-11-22 18:14:02

Description

The C library function void rewind(FILE *stream) sets the file position to the beginning of the file of the given stream.

Declaration

Following is the declaration for rewind() function.

void rewind(FILE *stream)

Parameters

  • stream − This is the pointer to a FILE object that identifies the stream.

Return Value

This function does not return any value.

Example

The following example shows the usage of rewind() function.

#include <stdio.h>

int main()
{
char str[] = "This is tutorialspoint.com";
FILE *fp;
int ch; /* First let's write some content in the file */
fp = fopen( "file.txt" , "w" );
fwrite(str , 1 , sizeof(str) , fp );
fclose(fp); fp = fopen( "file.txt" , "r" );
while(1)
{
ch = fgetc(fp);
if( feof(fp) )
{
break ;
}
printf("%c", ch);
}   //set the file position to the beginning, if it doesn't have this function, fp will point NULL ,because above while(1) and break when feof(fp) is true.
rewind(fp);
printf("\n");
while(1)
{
ch = fgetc(fp);
if( feof(fp) )
{
break ;
}
printf("%c", ch); }
fclose(fp); return(0);
}

Let us assume we have a text file file.txt that have the following content −

This is tutorialspoint.com

Now let us compile and run the above program to produce the following result −

This is tutorialspoint.com
This is tutorialspoint.com