fsetpos


function
<cstdio>
int fsetpos ( FILE * stream, const fpos_t * pos );

Set position indicator of stream

Changes the internal file position indicator associated with stream to a new position. The position parameter is a pointer to an fpos_t object whose value shall have been previously obtained with a call to fgetpos.
The End-of-File internal indicator of the stream is cleared after a call to this function, and all effects from previous calls to ungetc are dropped.
On streams open for update (read+write), a call to fsetpos allows to switch between reading and writing.

Parameters

stream
Pointer to a FILE object that identifies the stream.
position
Pointer to a fpos_t object containing a position previously obtained with fgetpos.


Return Value

If successful, the function returns a zero value.
Otherwise, it returns a nonzero value and sets the global variable errno to a positive value, which can be interpreted with perror.

Example

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/* fsetpos example */
#include <stdio.h>

int main ()
{
  FILE * pFile;
  fpos_t position;

  pFile = fopen ("myfile.txt","w");
  fgetpos (pFile, &position);
  fputs ("That is a sample",pFile);
  fsetpos (pFile, &position);
  fputs ("This",pFile);
  fclose (pFile);
  return 0;
}


After this code is successfully executed, a file called myfile.txt will contain:
This is a sample

See also

fgetpos Get current position in stream (function)
fseek Reposition stream position indicator (function)
rewind Set position indicator to the beginning (function)