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b6b9d458 | 1 | .\" -*-nroff-*- |
c4ccbbf9 MW |
2 | .\" |
3 | .\" Manual for event-driven line buffer | |
4 | .\" | |
5 | .\" (c) 1999--2002, 2005, 2009, 2023, 2024 Straylight/Edgeware | |
6 | .\" | |
7 | . | |
8 | .\"----- Licensing notice --------------------------------------------------- | |
9 | .\" | |
10 | .\" This file is part of the mLib utilities library. | |
11 | .\" | |
12 | .\" mLib is free software: you can redistribute it and/or modify it under | |
13 | .\" the terms of the GNU Library General Public License as published by | |
14 | .\" the Free Software Foundation; either version 2 of the License, or (at | |
15 | .\" your option) any later version. | |
16 | .\" | |
17 | .\" mLib is distributed in the hope that it will be useful, but WITHOUT | |
18 | .\" ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
19 | .\" FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public | |
20 | .\" License for more details. | |
21 | .\" | |
22 | .\" You should have received a copy of the GNU Library General Public | |
23 | .\" License along with mLib. If not, write to the Free Software | |
24 | .\" Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, | |
25 | .\" USA. | |
26 | . | |
27 | .\"-------------------------------------------------------------------------- | |
28 | .so ../defs.man \" @@@PRE@@@ | |
29 | . | |
30 | .\"-------------------------------------------------------------------------- | |
31 | .TH selbuf 3mLib "23 May 1999" "Straylight/Edgeware" "mLib utilities library" | |
08da152e | 32 | .\" @selbuf_enable |
33 | .\" @selbuf_disable | |
31e83d07 | 34 | .\" @selbuf_setsize |
08da152e | 35 | .\" @selbuf_init |
31e83d07 | 36 | .\" @selbuf_destroy |
c4ccbbf9 MW |
37 | . |
38 | .\"-------------------------------------------------------------------------- | |
39 | .SH NAME | |
40 | selbuf \- line-buffering input selector | |
41 | . | |
42 | .\"-------------------------------------------------------------------------- | |
b6b9d458 | 43 | .SH SYNOPSIS |
c4ccbbf9 | 44 | . |
b6b9d458 | 45 | .nf |
46 | .B "#include <mLib/selbuf.h>" | |
d056fbdf | 47 | .PP |
4729aa69 | 48 | .B "typedef struct { ...\& } selbuf;" |
d056fbdf | 49 | .PP |
b6b9d458 | 50 | .BI "void selbuf_enable(selbuf *" b ); |
51 | .BI "void selbuf_disable(selbuf *" b ); | |
cededfbe | 52 | .BI "void selbuf_setsize(selbuf *" b ", size_t " sz ); |
adec5584 MW |
53 | .ta \w'\fBvoid selbuf_init('u |
54 | .BI "void selbuf_init(selbuf *" b ", sel_state *" s ", int " fd , | |
55 | .BI " lbuf_func *" func ", void *" p ); | |
cededfbe | 56 | .BI "void selbuf_destroy(selbuf *" b ); |
b6b9d458 | 57 | .fi |
c4ccbbf9 MW |
58 | . |
59 | .\"-------------------------------------------------------------------------- | |
b6b9d458 | 60 | .SH DESCRIPTION |
61 | The | |
62 | .B selbuf | |
63 | subsystem is a selector which integrates with the | |
08da152e | 64 | .BR sel (3) |
b6b9d458 | 65 | system for I/O multiplexing. It reads entire text lines from a file |
66 | descriptor and passes them to a caller-defined function. It uses the | |
67 | line buffer described in | |
08da152e | 68 | .BR lbuf (3) |
b6b9d458 | 69 | to do its work: you should read about it in order to understand exactly |
70 | what gets considered to be a line of text and what doesn't, and the | |
71 | exact rules about what your line handling function should and shouldn't | |
72 | do. | |
73 | .PP | |
31e83d07 | 74 | The data for a line selector is stored in an object of type |
b6b9d458 | 75 | .BR selbuf . |
76 | This object must be allocated by the caller, and initialized using the | |
77 | .B selbuf_init | |
78 | function. This requires a fair few arguments: | |
79 | .TP | |
ff76c38f | 80 | .BI "selbuf *" b |
b6b9d458 | 81 | Pointer to the |
82 | .B selbuf | |
83 | object to initialize. | |
84 | .TP | |
ff76c38f | 85 | .BI "sel_state *" s |
b6b9d458 | 86 | Pointer to a multiplexor object (type |
87 | .BR sel_state ) | |
88 | to which this selector should be attached. See | |
08da152e | 89 | .BR sel (3) |
b6b9d458 | 90 | for more details about multiplexors, and how this whole system works. |
91 | .TP | |
ff76c38f | 92 | .BI "int " fd |
b6b9d458 | 93 | The file descriptor of the stream the selector should read from. |
94 | .TP | |
b342b114 | 95 | .BI "lbuf_func *" func |
b6b9d458 | 96 | The |
97 | .I "line handler" | |
98 | function. It is passed a pointer to each line read from the file (or | |
b342b114 | 99 | null to indicate end-of-file), the length of the line, and an arbitrary |
100 | pointer (the | |
b6b9d458 | 101 | .I p |
102 | argument to | |
103 | .B selbuf_init | |
b342b114 | 104 | described below). For full details, see |
105 | .BR lbuf (3). | |
b6b9d458 | 106 | .TP |
ff76c38f | 107 | .BI "void *" p |
b6b9d458 | 108 | A pointer argument passed to |
109 | .I func | |
110 | for each line read from the file. Apart from this, the pointer is not | |
111 | used at all. | |
112 | .PP | |
113 | The | |
114 | .B selbuf | |
115 | selector is immediately active. Subsequent calls to | |
116 | .B sel_select | |
117 | on the same multiplexor will cause any complete lines read from the file | |
118 | to be passed to your handling function. This function can at any time | |
119 | call | |
120 | .B selbuf_disable | |
121 | to stop itself from being called any more. The selector is then | |
122 | disengaged from the I/O multiplexor and won't do anything until | |
123 | .B selbuf_enable | |
124 | is called. Note that | |
125 | .B selbuf_enable | |
126 | may well immediately start emitting complete lines of text which were | |
127 | queued up from the last I/O operation: it doesn't necessarily wait for | |
128 | the next | |
129 | .B sel_select | |
130 | call. | |
cededfbe | 131 | .PP |
132 | The line buffer has a finite amount of memory for reading strings. The | |
133 | size of this buffer is set by calling | |
134 | .B selbuf_setsize | |
135 | with the requested size. The default buffer size is 256 bytes. | |
136 | .PP | |
137 | When it's finished with, a line buffer selector must be destroyed by | |
138 | calling | |
139 | .BR selbuf_destroy . | |
c4ccbbf9 MW |
140 | . |
141 | .\"-------------------------------------------------------------------------- | |
08da152e | 142 | .SH "SEE ALSO" |
c4ccbbf9 | 143 | . |
08da152e | 144 | .BR lbuf (3), |
145 | .BR sel (3), | |
146 | .BR mLib (3). | |
c4ccbbf9 MW |
147 | . |
148 | .\"-------------------------------------------------------------------------- | |
b6b9d458 | 149 | .SH AUTHOR |
c4ccbbf9 | 150 | . |
9b5ac6ff | 151 | Mark Wooding, <mdw@distorted.org.uk> |
c4ccbbf9 MW |
152 | . |
153 | .\"----- That's all, folks -------------------------------------------------- |