mansearch.3

   1 .\"     $Id: mansearch.3,v 1.5 2017/03/30 22:22:05 schwarze Exp $
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   3 .\" Copyright (c) 2014 Ingo Schwarze <schwarze@openbsd.org>
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  17 .Dd $Mdocdate: March 30 2017 $
  18 .Dt MANSEARCH 3
  19 .Os
  20 .Sh NAME
  21 .Nm mansearch
  22 .Nd search manual page databases
  23 .Sh SYNOPSIS
  24 .In stdint.h
  25 .In manconf.h
  26 .In mansearch.h
  27 .Ft int
  28 .Fo mansearch
  29 .Fa "const struct mansearch *search"
  30 .Fa "const struct manpaths *paths"
  31 .Fa "int argc"
  32 .Fa "char *argv[]"
  33 .Fa "struct manpage **res"
  34 .Fa "size_t *sz"
  35 .Fc
  36 .Sh DESCRIPTION
  37 The
  38 .Fn mansearch
  39 function returns information about manuals matching a search query from a
  40 .Xr mandoc.db 5
  41 database.
  42 .Pp
  43 The query arguments are as follows:
  44 .Bl -tag -width Ds
  45 .It Fa "const struct mansearch *search"
  46 Search options, defined in
  47 .In mansearch.h .
  48 .It Fa "const struct manpaths *paths"
  49 Directories to be searched, defined in
  50 .In manconf.h .
  51 .It Fa "int argc" , "char *argv[]"
  52 Search criteria, usually taken from the command line.
  53 .El
  54 .Pp
  55 The output arguments are as follows:
  56 .Bl -tag -width Ds
  57 .It Fa "struct manpage **res"
  58 Returns a pointer to an array of result structures defined in
  59 .In mansearch.h .
  60 The user is expected to call
  61 .Xr free 3
  62 on the
  63 .Va file ,
  64 .Va names ,
  65 and
  66 .Va output
  67 fields of all structures, as well as the
  68 .Fa res
  69 array itself.
  70 .It Fa "size_t *sz"
  71 Returns the number of result structures contained in
  72 .Fa res .
  73 .El
  74 .Sh IMPLEMENTATION NOTES
  75 For each manual page tree, the search is done in two steps.
  76 In the first step, a list of pages matching the search criteria is built.
  77 In the second step, the requested information about these pages is
  78 retrieved from the database and assembled into the
  79 .Fa res
  80 array.
  81 .Pp
  82 All function mentioned here are defined in the file
  83 .Pa mansearch.c .
  84 .Ss Finding matches
  85 Command line parsing is done by the function
  86 .Fn exprcomp
  87 building a singly linked list of
  88 .Vt expr
  89 structures, using the helper functions
  90 .Fn expr_and
  91 and
  92 .Fn exprterm .
  93 .Ss Assembling the results
  94 The names, sections, and architectures of the manuals found
  95 are assembled into the
  96 .Va names
  97 field of the result structure by the function
  98 .Fn buildnames .
  99 .Sh FILES
 100 .Bl -tag -width mandoc.db -compact
 101 .It Pa mandoc.db
 102 The manual page database.
 103 .El
 104 .Sh SEE ALSO
 105 .Xr apropos 1 ,
 106 .Xr mandoc.db 5 ,
 107 .Xr makewhatis 8
 108 .Sh HISTORY
 109 The
 110 .Fn mansearch
 111 subsystem first appeared in
 112 .Ox 5.6 .
 113 .Sh AUTHORS
 114 .An -nosplit
 115 A module to search manual page databases was first written by
 116 .An Kristaps Dzonsons Aq Mt kristaps@bsd.lv
 117 in 2011, at first using the Berkeley DB;
 118 he rewrote it for SQLite3 in 2012, and
 119 .An Ingo Schwarze Aq Mt schwarze@openbsd.org
 120 removed the dependency on SQLite3 in 2016.