xref: /386bsd/usr/share/man/cat3/fseek.0 (revision a2142627) 
1FSEEK(3)                  386BSD Programmer's Manual                  FSEEK(3)
2
3NNAAMMEE
4     ffggeettppooss, ffsseeeekk, ffsseettppooss, fftteellll, rreewwiinndd - reposition a stream
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6SSYYNNOOPPSSIISS
7     ##iinncclluuddee <<ssttddiioo..hh>>
8
9     _i_n_t
10     ffsseeeekk(_F_I_L_E *_s_t_r_e_a_m, _l_o_n_g _o_f_f_s_e_t, _i_n_t _w_h_e_n_c_e)
11
12     _l_o_n_g
13     fftteellll(_F_I_L_E *_s_t_r_e_a_m)
14
15     _v_o_i_d
16     rreewwiinndd(_F_I_L_E *_s_t_r_e_a_m)
17
18     _i_n_t
19     ffggeettppooss(_F_I_L_E *_s_t_r_e_a_m, _f_p_o_s__t *_p_o_s)
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21     _i_n_t
22     ffsseettppooss(_F_I_L_E *_s_t_r_e_a_m, _f_p_o_s__t *_p_o_s)
23
24DDEESSCCRRIIPPTTIIOONN
25     The ffsseeeekk() function sets the file position indicator for the stream
26     pointed to by _s_t_r_e_a_m. The new position, measured in bytes, is obtained by
27     adding _o_f_f_s_e_t bytes to the position specified by _w_h_e_n_c_e. If _w_h_e_n_c_e is set
28     to SEEK_SET, SEEK_CUR, or SEEK_END, the offset is relative to the start
29     of the file, the current position indicator, or end-of-file,
30     respectively.  A successful call to the ffsseeeekk() function clears the end-
31     of-file indicator for the stream and undoes any effects of the ungetc(3)
32     function on the same stream.
33
34     The fftteellll() function obtains the current value of the file position
35     indicator for the stream pointed to by _s_t_r_e_a_m.
36
37     The rreewwiinndd() function sets the file position indicator for the stream
38     pointed to by _s_t_r_e_a_m to the beginning of the file.  It is equivalent to:
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40           (void)fseek(stream, 0L, SEEK_SET)
41
42     except that the error indicator for the stream is also cleared (see
43     clearerr(3)).
44
45     The ffggeettppooss() and ffsseettppooss() functions are alternate interfaces equivalent
46     to fftteellll() and ffsseeeekk() (with whence set to SEEK_SET ), setting and
47     storing the current value of the file offset into or from the object
48     referenced by _p_o_s. On some (non-UNIX) systems an ``_f_p_o_s__t'' object may be
49     a complex object and these routines may be the only way to portably
50     reposition a text stream.
51
52RREETTUURRNN VVAALLUUEESS
53     The rreewwiinndd() function returns no value.  Upon successful completion,
54     ffggeettppooss(), ffsseeeekk(), ffsseettppooss() return 0, and fftteellll() returns the current
55     offset.  Otherwise, -1 is returned and the global variable errno is set
56     to indicate the error.
57
58EERRRROORRSS
59     [EBADF]   The _s_t_r_e_a_m specified is not a seekable stream.
60
61     [EINVAL]  The _w_h_e_n_c_e argument to ffsseeeekk() was not SEEK_SET, SEEK_END, or
62               SEEK_CUR.
63
64     The function ffggeettppooss(), ffsseeeekk(), ffsseettppooss(), and fftteellll() may also fail and
65     set _e_r_r_n_o for any of the errors specified for the routines fflush(3),
66     fstat(2),  lseek(2),  and malloc(3).
67
68SSEEEE AALLSSOO
69     lseek(2)
70
71SSTTAANNDDAARRDDSS
72     The ffggeettppooss(), ffsseettppooss(), ffsseeeekk(), fftteellll(), and rreewwiinndd() functions
73     conform to ANSI C3.159-1989 (``ANSI C'').
74
75BSD Experimental                 June 29, 1991                               2
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