std::fseek

 

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

Sets the file position indicator for the file stream stream as follows:

If the stream is open in binary mode, the new position is exactly offset bytes measured from the beginning of the file is 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.

Parameters

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

Template:cpp/io/c/dcl list fsetposTemplate:cpp/io/c/dcl list fgetposTemplate:cpp/io/c/dcl list ftellTemplate:cpp/io/c/dcl list rewind

C documentation for fseek