C stdio fseek() Function
Example
Read the character at position 4 from the start of the file:
FILE *fptr;
fptr = fopen("filename.txt", "r");
fseek(fptr, 4,
SEEK_SET);
char c = fgetc(fptr);
printf("%c", c);
fclose(fptr);
Definition and Usage
The fseek() function moves the position indicator to a specified position in
the file.
The fseek() function is defined in the <stdio.h> header file.
Syntax
fseek(FILE * fptr, long int offset, int origin);Parameter Values
| Parameter | Description |
|---|---|
| fptr |
Required. A file pointer, usually created by the fopen() function.
|
| offset | Required. Specifies a position in the file relative to the origin. |
| origin |
Required. Specifies the position in the file from which the offset is applied. It can be one of the
following constants:
SEEK_END value may not be fully supported by some implementations of
the library.
|
Technical Details
| Returns: | An int value which is zero if successful and non-zero
if an error occurred. |
|---|
More Examples
Example
Find the size of the file by moving the position indicator to the end of the file and then checking its position
// Open a file
FILE *fptr;
fptr = fopen("filename.txt", "r");
// Move the position indicator to the end of the file
fseek(fptr, 0,
SEEK_END);
// Read the position
int position = ftell(fptr);
// Display the value
printf("%d", position);
fclose(fptr);