< cpp‎ | io‎ | c
Revision as of 21:56, 25 June 2013 by P12 (Talk | contribs)

Defined in header <cstdio>
int fseek( std::FILE* stream, long offset, int origin );

Sets the file position indicator for the file stream stream.

If the stream is open in binary mode, the new position is exactly offset bytes measured from the beginning of the file if origin is SEEK_SET, from the current file position if origin is SEEK_CUR, and from the end of the file if origin is SEEK_END. Some binary streams may not support the SEEK_END.

If the stream is open in text mode, the only supported values for offset are zero (which works with any origin) and a value returned by an earlier call to std::ftell on a stream associated with the same file (which only works with origin of SEEK_SET.

In addition to changing the file position indicator, fseek undoes the effects of std::ungetc and clears the end-of-file status, if applicable.

If a read or write error occurs, the error indicator for the stream (std::ferror) is set and the file position is unaffected.



stream - file stream to modify
offset - number of characters to shift the position relative to origin
origin - position to which offset is added. It can have one of the following values: SEEK_SET, SEEK_CUR, SEEK_END

Return value

0 upon success, nonzero value otherwise.


See also

moves the file position indicator to a specific location in a file
(function) [edit]
gets the file position indicator
(function) [edit]
returns the current file position indicator
(function) [edit]
moves the file position indicator to the beginning in a file
(function) [edit]
C documentation for fseek