| 1 | .\" -*-nroff-*- |
| 2 | .TH mLib 3 "7 July 1999" mLib |
| 3 | .SH NAME |
| 4 | mLib \- library of miscellaneous utilities |
| 5 | .\" @mLib |
| 6 | .SH DESCRIPTION |
| 7 | The |
| 8 | .B mLib |
| 9 | library is a mixed back of things which the author finds useful in large |
| 10 | numbers of programs. As a result, its structure is somewhat arbitrary, |
| 11 | and it's accreted extra bits over time rather than actually being |
| 12 | designed as a whole. In the author's opinion this isn't too much of a |
| 13 | hardship. |
| 14 | .PP |
| 15 | At the most granular level, |
| 16 | .B mLib |
| 17 | is split into `modules', each of which has its own header file and |
| 18 | manual page. Sometimes there are identifiable `chunks' of several |
| 19 | modules which fit together as a whole. Modules and chunks fit into |
| 20 | `layers', each depending on the ones below it. The header file for |
| 21 | module |
| 22 | .I foo |
| 23 | would be put in |
| 24 | .BR <mLib/ \c |
| 25 | .IR foo \c |
| 26 | .BR > . |
| 27 | .PP |
| 28 | This description is a bit abstract, and |
| 29 | .BR mLib , |
| 30 | as a result of its history, doesn't fit it as well as I might like. |
| 31 | Even so, it's not too bad a model really. |
| 32 | .PP |
| 33 | The rest of this section describes the various chunks and layers. |
| 34 | .SS "Exception handling" |
| 35 | Right at the bottom, there's a fairly primitive exception handling |
| 36 | system. It's provided by the |
| 37 | .B exc |
| 38 | module, and stands alone. It's used mainly by the memory allocation |
| 39 | modules to raise exceptions when there's no more memory to be had. |
| 40 | .SS "Memory allocation" |
| 41 | The |
| 42 | .B alloc |
| 43 | module provides simple veneers onto traditional memory allocation |
| 44 | functions like |
| 45 | .BR malloc (3) |
| 46 | and |
| 47 | .BR strdup (3) |
| 48 | (although |
| 49 | .B mLib |
| 50 | doesn't actually depend on |
| 51 | .B strdup |
| 52 | being defined in the library) which raise exceptions when there's not |
| 53 | enough memory left. |
| 54 | .PP |
| 55 | The |
| 56 | .B sub |
| 57 | module handles efficient allocation of small blocks. It allocates |
| 58 | memory in relatively big chunks and divides the chunks up into small |
| 59 | blocks before returning them. It keeps lists of differently-sized |
| 60 | blocks so allocation and freeing is fast. The downside is that your |
| 61 | code must know how big a block is when it's being freed. |
| 62 | .PP |
| 63 | The |
| 64 | .B track |
| 65 | module (not yet documented) is a simple memory allocation tracker. It |
| 66 | can be handy when trying to fix memory leaks. |
| 67 | .SS "String handling" |
| 68 | The |
| 69 | .B str |
| 70 | module provides some trivial string-manipulation functions which tend to |
| 71 | be useful quite often. |
| 72 | .PP |
| 73 | The |
| 74 | .B dstr |
| 75 | module implements a dynamic string data type. It works quite quickly |
| 76 | and well, and is handy in security-sensitive programs, to prevent |
| 77 | buffer-overflows. Dynamic strings are used occasionally through the |
| 78 | rest of the library, mainly as output arguments. |
| 79 | .PP |
| 80 | The |
| 81 | .B dspool |
| 82 | module implements a `pool' of dynamic strings which saves lots of |
| 83 | allocation and deallocation when a piece of code has high string |
| 84 | turnover. |
| 85 | .SS "Program identification and error reporting" |
| 86 | The |
| 87 | .B quis |
| 88 | module remembers the name of the program and supplies it when asked. |
| 89 | It's used in error messages and similar things. |
| 90 | .PP |
| 91 | The |
| 92 | .B report |
| 93 | module emits standard Unixy error messages. It provides functions |
| 94 | .B moan |
| 95 | and |
| 96 | .B die |
| 97 | which the author uses rather a lot. |
| 98 | .PP |
| 99 | The |
| 100 | .B trace |
| 101 | module (not yet documented) |
| 102 | provides an interface for emitting tracing information with configurable |
| 103 | verbosity levels. It needs improving to be able to cope with outputting |
| 104 | to the system log. |
| 105 | .SS "Other data types" |
| 106 | The |
| 107 | .B sym |
| 108 | module implements a rather good extending hash table. Keys and values can |
| 109 | be arbitrary data. |
| 110 | .PP |
| 111 | The |
| 112 | .B dynarray |
| 113 | module (not yet documented) implements unbounded sparse arrays. It |
| 114 | needs rewriting. |
| 115 | .SS "Miscellaneous utilities" |
| 116 | The |
| 117 | .B crc32 |
| 118 | module calculates CRC values for strings. It's used by the symbol table |
| 119 | manager as a hash function. |
| 120 | .PP |
| 121 | The |
| 122 | .B lock |
| 123 | module does POSIX |
| 124 | .BR fcntl (2)-style |
| 125 | locking with a timeout. |
| 126 | .PP |
| 127 | The |
| 128 | .B lbuf |
| 129 | module implements a `line buffer', which is an object that emits |
| 130 | completed lines of text from an incoming asynchronous data stream. It's |
| 131 | remarkably handy in programs that want to read lines from pipes and |
| 132 | sockets can't block while waiting for a line-end to arrive. |
| 133 | .PP |
| 134 | The |
| 135 | .B tv |
| 136 | module provides some macros and functions for playing with |
| 137 | .B "struct timeval" |
| 138 | .PP |
| 139 | The |
| 140 | .B bits |
| 141 | module defines some types and macros for playing with words as chunks of |
| 142 | bits. There are portable rotate and shift macros (harder than you'd |
| 143 | think), and macros to do loading and storing in known-endian formats. |
| 144 | values. |
| 145 | .PP |
| 146 | The |
| 147 | .B mdwopt |
| 148 | module implements a fairly serious options parser compatible with the |
| 149 | GNU options parser. |
| 150 | .PP |
| 151 | The |
| 152 | .B testrig |
| 153 | module provides a generic structure for reading test vectors from files |
| 154 | and running them through functions. I mainly use it for testing |
| 155 | cryptographic transformations of various kinds. |
| 156 | .SS "Encoding and decoding" |
| 157 | The |
| 158 | .B base64 |
| 159 | module does base64 encoding and decoding, as defined in RFC2045. Base64 |
| 160 | encodes arbitrary binary data in a reliable way which is resistant to |
| 161 | character-set transformations and other mail transport bogosity. |
| 162 | .PP |
| 163 | The |
| 164 | .B url |
| 165 | module does urlencoding and decoding, as defined in RFC1866. |
| 166 | Urlencoding encodes arbitrary (but mostly text-like) name/value pairs as |
| 167 | a text string containing no whitespace. |
| 168 | .SS "Multiplexed I/O" |
| 169 | The |
| 170 | .B sel |
| 171 | module provides a basis for doing nonblocking I/O in Unix systems. It |
| 172 | provides types and functions for receiving events when files are ready |
| 173 | for reading or writing, and when timers expire. |
| 174 | .PP |
| 175 | The |
| 176 | .B conn |
| 177 | module implements nonblocking network connections in a way which fits in |
| 178 | with the |
| 179 | .B sel |
| 180 | system. It makes nonblocking connects pretty much trivial. |
| 181 | .PP |
| 182 | The |
| 183 | .B selbuf |
| 184 | module attaches to the |
| 185 | .B sel |
| 186 | system and sends an event when lines of text arrive on a file. It's |
| 187 | useful when reading text from a network connection. |
| 188 | .SH "SEE ALSO" |
| 189 | .BR alloc (3), |
| 190 | .BR base64 (3), |
| 191 | .BR bits (3), |
| 192 | .BR conn (3), |
| 193 | .BR crc32 (3), |
| 194 | .BR dspool (3), |
| 195 | .BR dstr (3), |
| 196 | .BR exc (3), |
| 197 | .BR lbuf (3), |
| 198 | .BR lock (3), |
| 199 | .BR mdwopt (3), |
| 200 | .BR quis (3), |
| 201 | .BR report (3), |
| 202 | .BR sel (3), |
| 203 | .BR selbuf (3), |
| 204 | .BR str (3), |
| 205 | .BR sub (3), |
| 206 | .BR sym (3), |
| 207 | .BR tv (3), |
| 208 | .BR url (3). |
| 209 | .SH AUTHOR |
| 210 | Mark Wooding, <mdw@nsict.org> |