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author | tjr <tjr@FreeBSD.org> | 2004-03-20 08:38:27 +0000 |
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committer | tjr <tjr@FreeBSD.org> | 2004-03-20 08:38:27 +0000 |
commit | 55f1dd7399d8d3f2e32a4d9db7add77e9900e64a (patch) | |
tree | 2deb085f24b965bfb6498537e189e40f2330b977 /lib/libc | |
parent | 7ec9985db2ca35ddd34202785018bd162fa7d232 (diff) | |
download | FreeBSD-src-55f1dd7399d8d3f2e32a4d9db7add77e9900e64a.zip FreeBSD-src-55f1dd7399d8d3f2e32a4d9db7add77e9900e64a.tar.gz |
Improve documentation for fgetpos() and fsetpos(), and discourage
users from assuming that fpos_t is an integral type.
Diffstat (limited to 'lib/libc')
-rw-r--r-- | lib/libc/stdio/fseek.3 | 34 |
1 files changed, 21 insertions, 13 deletions
diff --git a/lib/libc/stdio/fseek.3 b/lib/libc/stdio/fseek.3 index 41493be..96abc0a 100644 --- a/lib/libc/stdio/fseek.3 +++ b/lib/libc/stdio/fseek.3 @@ -36,7 +36,7 @@ .\" @(#)fseek.3 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd October 12, 2002 +.Dd March 19, 2004 .Dt FSEEK 3 .Os .Sh NAME @@ -149,21 +149,29 @@ The and .Fn fsetpos functions -are alternate interfaces equivalent to +are alternate interfaces for retrieving and setting the current position in +the file, similar to .Fn ftell and -.Fn fseek -(with whence set to -.Dv SEEK_SET ) , -setting and storing the current value of -the file offset into or from the object referenced by +.Fn fseek , +except that the current position is stored in an opaque object of +type +.Vt fpos_t +pointed to by .Fa pos . -On some -.Pq non- Ns Tn UNIX -systems an -.Dq Fa fpos_t -object may be a complex object -and these routines may be the only way to portably reposition a text stream. +These functions provide a portable way to seek to offsets larger than +those that can be represented by a +.Vt long int . +They may also store additional state information in the +.Vt fpos_t +object to facilitate seeking within files containing multibyte +characters with state-dependent encodings. +Although +.Vt fpos_t +has traditionally been an integral type, +applications cannot assume that it is; +in particular, they must not perform arithmetic on objects +of this type. .Pp If the stream is a wide character stream (see .Xr fwide 3 ) , |