2 .TH selbuf 3 "23 May 1999" "Straylight/Edgeware" "mLib utilities library"
4 selbuf \- line-buffering input selector
12 .B "#include <mLib/selbuf.h>"
14 .BI "void selbuf_enable(selbuf *" b );
15 .BI "void selbuf_disable(selbuf *" b );
16 .BI "void selbuf_setsize(selbuf *" b ", size_t " sz );
17 .BI "void selbuf_init(selbuf *" b ", sel_state *" s ", int " fd ,
18 .BI " lbuf_func *" func ", void *" p );
19 .BI "void selbuf_destroy(selbuf *" b );
24 subsystem is a selector which integrates with the
26 system for I/O multiplexing. It reads entire text lines from a file
27 descriptor and passes them to a caller-defined function. It uses the
28 line buffer described in
30 to do its work: you should read about it in order to understand exactly
31 what gets considered to be a line of text and what doesn't, and the
32 exact rules about what your line handling function should and shouldn't
35 The data for a line selector is stored in an object of type
37 This object must be allocated by the caller, and initialized using the
39 function. This requires a fair few arguments:
47 Pointer to a multiplexor object (type
49 to which this selector should be attached. See
51 for more details about multiplexors, and how this whole system works.
54 The file descriptor of the stream the selector should read from.
56 .BI "lbuf_func *" func
59 function. It is passed a pointer to each line read from the file (or
60 null to indicate end-of-file), the length of the line, and an arbitrary
65 described below). For full details, see
69 A pointer argument passed to
71 for each line read from the file. Apart from this, the pointer is not
76 selector is immediately active. Subsequent calls to
78 on the same multiplexor will cause any complete lines read from the file
79 to be passed to your handling function. This function can at any time
82 to stop itself from being called any more. The selector is then
83 disengaged from the I/O multiplexor and won't do anything until
87 may well immediately start emitting complete lines of text which were
88 queued up from the last I/O operation: it doesn't necessarily wait for
93 The line buffer has a finite amount of memory for reading strings. The
94 size of this buffer is set by calling
96 with the requested size. The default buffer size is 256 bytes.
98 When it's finished with, a line buffer selector must be destroyed by
106 Mark Wooding, <mdw@distorted.org.uk>