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36 .\" @(#)fseek.3 8.1 (Berkeley) 6/4/93
37 .\" $FreeBSD: src/lib/libc/stdio/fseek.3,v 1.5.2.7 2001/12/14 18:33:57 ru Exp $
38 .\" $DragonFly: src/lib/libc/stdio/fseek.3,v 1.3 2007/07/30 22:11:33 swildner Exp $
51 .Nd reposition a stream
57 .Fn fseek "FILE *stream" "long offset" "int whence"
59 .Fn ftell "FILE *stream"
61 .Fn rewind "FILE *stream"
63 .Fn fgetpos "FILE *stream" "fpos_t *pos"
65 .Fn fsetpos "FILE *stream" "const fpos_t *pos"
68 .Fn fseeko "FILE *stream" "off_t offset" "int whence"
70 .Fn ftello "FILE *stream"
74 function sets the file position indicator for the stream pointed
77 The new position, measured in bytes, is obtained by adding
79 bytes to the position specified by
88 the offset is relative to the
89 start of the file, the current position indicator, or end-of-file,
91 A successful call to the
93 function clears the end-of-file indicator for the stream and undoes
96 function on the same stream.
101 obtains the current value of the file position indicator for the
107 function sets the file position indicator for the stream pointed
110 to the beginning of the file.
113 .Dl (void)fseek(stream, 0L, SEEK_SET)
115 except that the error indicator for the stream is also cleared
121 function is identical to
130 function is identical to
140 are alternate interfaces equivalent to
146 setting and storing the current value of
147 the file offset into or from the object referenced by
153 object may be a complex object
154 and these routines may be the only way to portably reposition a text stream.
161 .Rv -std fgetpos fseek fseeko fsetpos
163 Upon successful completion,
167 return the current offset.
168 Otherwise, \-1 is returned and the global variable
170 is set to indicate the error.
177 is not a seekable stream.
191 the resulting file offset would be a value which
192 cannot be represented correctly in an object of type long.
203 may also fail and set
205 for any of the errors specified for the routines