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1 | package lib; |
2 | |
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3 | use Config; |
4 | |
5 | my $archname = $Config{'archname'}; |
6 | |
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7 | @ORIG_INC = (); # (avoid typo warning) |
8 | @ORIG_INC = @INC; # take a handy copy of 'original' value |
9 | |
10 | |
11 | sub import { |
12 | shift; |
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13 | foreach (@_) { |
14 | unshift(@INC, $_); |
15 | # Put a corresponding archlib directory infront of $_ if it |
16 | # looks like $_ has an archlib directory below it. |
17 | unshift(@INC, "$_/$archname") if -d "$_/$archname/auto"; |
18 | } |
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19 | } |
20 | |
21 | |
22 | sub unimport { |
23 | shift; |
24 | my $mode = shift if $_[0] =~ m/^:[A-Z]+/; |
25 | |
26 | my %names; |
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27 | foreach(@_) { |
28 | ++$names{$_}; |
29 | ++$names{"$_/$archname"} if -d "$_/$archname/auto"; |
30 | } |
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31 | |
32 | if ($mode and $mode eq ':ALL') { |
33 | # Remove ALL instances of each named directory. |
34 | @INC = grep { !exists $names{$_} } @INC; |
35 | } else { |
36 | # Remove INITIAL instance(s) of each named directory. |
37 | @INC = grep { --$names{$_} < 0 } @INC; |
38 | } |
39 | } |
40 | |
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41 | 1; |
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42 | __END__ |
43 | |
44 | =head1 NAME |
45 | |
46 | lib - manipulate @INC at compile time |
47 | |
48 | =head1 SYNOPSIS |
49 | |
50 | use lib LIST; |
51 | |
52 | no lib LIST; |
53 | |
54 | =head1 DESCRIPTION |
55 | |
56 | This is a small simple module which simplifies the manipulation of @INC |
57 | at compile time. |
58 | |
59 | It is typically used to add extra directories to perl's search path so |
60 | that later C<use> or C<require> statements will find modules which are |
61 | not located on perl's default search path. |
62 | |
63 | |
64 | =head2 ADDING DIRECTORIES TO @INC |
65 | |
66 | The parameters to C<use lib> are added to the start of the perl search |
67 | path. Saying |
68 | |
69 | use lib LIST; |
70 | |
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71 | is I<almost> the same as saying |
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72 | |
73 | BEGIN { unshift(@INC, LIST) } |
74 | |
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75 | For each directory in LIST (called $dir here) the lib module also |
76 | checks to see if a directory called $dir/$archname/auto exists. |
77 | If so the $dir/$archname directory is assumed to be a corresponding |
78 | architecture specific directory and is added to @INC in front of $dir. |
79 | |
80 | If LIST includes both $dir and $dir/$archname then $dir/$archname will |
81 | be added to @INC twice (if $dir/$archname/auto exists). |
82 | |
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83 | |
84 | =head2 DELETING DIRECTORIES FROM @INC |
85 | |
86 | You should normally only add directories to @INC. If you need to |
87 | delete directories from @INC take care to only delete those which you |
88 | added yourself or which you are certain are not needed by other modules |
89 | in your script. Other modules may have added directories which they |
90 | need for correct operation. |
91 | |
92 | By default the C<no lib> statement deletes the I<first> instance of |
93 | each named directory from @INC. To delete multiple instances of the |
94 | same name from @INC you can specify the name multiple times. |
95 | |
96 | To delete I<all> instances of I<all> the specified names from @INC you can |
97 | specify ':ALL' as the first parameter of C<no lib>. For example: |
98 | |
99 | no lib qw(:ALL .); |
100 | |
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101 | For each directory in LIST (called $dir here) the lib module also |
102 | checks to see if a directory called $dir/$archname/auto exists. |
103 | If so the $dir/$archname directory is assumed to be a corresponding |
104 | architecture specific directory and is also deleted from @INC. |
105 | |
106 | If LIST includes both $dir and $dir/$archname then $dir/$archname will |
107 | be deleted from @INC twice (if $dir/$archname/auto exists). |
108 | |
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109 | |
110 | =head2 RESTORING ORIGINAL @INC |
111 | |
112 | When the lib module is first loaded it records the current value of @INC |
113 | in an array C<@lib::ORIG_INC>. To restore @INC to that value you |
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114 | can say |
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115 | |
116 | @INC = @lib::ORIG_INC; |
117 | |
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118 | |
119 | =head1 SEE ALSO |
120 | |
121 | AddINC - optional module which deals with paths relative to the source file. |
122 | |
123 | =head1 AUTHOR |
124 | |
125 | Tim Bunce, 2nd June 1995. |
126 | |
127 | =cut |
128 | |