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The function fread () in C

Function size_t fread (void * ptr, size_t size, size_t nmemb, FILE * stream) in standard C Library reads data from the given stream into the pointed array, by ptr .

Declare the function fread () in C

Below is the declaration for the fread () function in C:

 size_t fread ( void * ptr , size_t size , size_t nmemb , FILE * stream )

Parameters

ptr - This is a pointer to a memory block with a minimum size of size * nmemb bytes.

size - This is the size (byte value) of each element to be read.

nmemb - This is the number of elements, with each element having the size of byte size.

stream - This is the pointer to a FILE object that defines an Input Stream.

Returns the value

The total number of successfully read elements is returned as a size_t object, which is an integer data type. If this number is different from the nmemb parameter, then an error has occurred or End-Of-File has been encountered.

For example

The following program C illustrates the usage of the fread () function in C:

 #include #include int main () { FILE * fp ; char c [] = "Hoc C co ban va nang cao tai QTM !!!" ; char buffer [ 100 ]; /* mo file de doc va ghi */ fp = fopen ( "baitapc.txt" , "w+" ); /* Ghi du lieu vao file */ fwrite ( c , strlen ( c ) + 1 , 1 , fp ); /* thiet lap vi tri con tro tim kiem ve dau file */ fseek ( fp , SEEK_SET , 0 ); /* Doc va hien thi du lieu */ fread ( buffer , strlen ( c )+ 1 , 1 , fp ); printf ( "%sn" , buffer ); fclose ( fp ); return ( 0 ); }

Compile and run the above C program to see the results:

According to Tutorialspoint

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