Commit | Line | Data |
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e50aee73 AD |
1 | package lib; |
2 | ||
774d564b | 3 | use vars qw(@ORIG_INC); |
4633a7c4 LW |
4 | use Config; |
5 | ||
6 | my $archname = $Config{'archname'}; | |
7 | ||
e50aee73 AD |
8 | @ORIG_INC = @INC; # take a handy copy of 'original' value |
9 | ||
10 | ||
11 | sub import { | |
12 | shift; | |
a5f75d66 | 13 | foreach (reverse @_) { |
016609bc BP |
14 | ## Ignore this if not defined. |
15 | next unless defined($_); | |
16 | if ($_ eq '') { | |
af3dad46 | 17 | require Carp; |
774d564b | 18 | Carp::carp("Empty compile time value given to use lib"); |
19 | # at foo.pl line ... | |
af3dad46 | 20 | } |
4633a7c4 LW |
21 | unshift(@INC, $_); |
22 | # Put a corresponding archlib directory infront of $_ if it | |
23 | # looks like $_ has an archlib directory below it. | |
774d564b | 24 | if (-d "$_/$archname") { |
25 | unshift(@INC, "$_/$archname") if -d "$_/$archname/auto"; | |
26 | unshift(@INC, "$_/$archname/$]") if -d "$_/$archname/$]/auto"; | |
27 | } | |
4633a7c4 | 28 | } |
e50aee73 AD |
29 | } |
30 | ||
31 | ||
32 | sub unimport { | |
33 | shift; | |
34 | my $mode = shift if $_[0] =~ m/^:[A-Z]+/; | |
35 | ||
36 | my %names; | |
4633a7c4 LW |
37 | foreach(@_) { |
38 | ++$names{$_}; | |
39 | ++$names{"$_/$archname"} if -d "$_/$archname/auto"; | |
40 | } | |
e50aee73 AD |
41 | |
42 | if ($mode and $mode eq ':ALL') { | |
43 | # Remove ALL instances of each named directory. | |
44 | @INC = grep { !exists $names{$_} } @INC; | |
45 | } else { | |
46 | # Remove INITIAL instance(s) of each named directory. | |
47 | @INC = grep { --$names{$_} < 0 } @INC; | |
48 | } | |
49 | } | |
50 | ||
4633a7c4 | 51 | 1; |
e50aee73 AD |
52 | __END__ |
53 | ||
54 | =head1 NAME | |
55 | ||
56 | lib - manipulate @INC at compile time | |
57 | ||
58 | =head1 SYNOPSIS | |
59 | ||
60 | use lib LIST; | |
61 | ||
62 | no lib LIST; | |
63 | ||
64 | =head1 DESCRIPTION | |
65 | ||
66 | This is a small simple module which simplifies the manipulation of @INC | |
67 | at compile time. | |
68 | ||
69 | It is typically used to add extra directories to perl's search path so | |
70 | that later C<use> or C<require> statements will find modules which are | |
71 | not located on perl's default search path. | |
72 | ||
e50aee73 AD |
73 | =head2 ADDING DIRECTORIES TO @INC |
74 | ||
75 | The parameters to C<use lib> are added to the start of the perl search | |
76 | path. Saying | |
77 | ||
78 | use lib LIST; | |
79 | ||
4633a7c4 | 80 | is I<almost> the same as saying |
e50aee73 AD |
81 | |
82 | BEGIN { unshift(@INC, LIST) } | |
83 | ||
4633a7c4 LW |
84 | For each directory in LIST (called $dir here) the lib module also |
85 | checks to see if a directory called $dir/$archname/auto exists. | |
86 | If so the $dir/$archname directory is assumed to be a corresponding | |
87 | architecture specific directory and is added to @INC in front of $dir. | |
88 | ||
89 | If LIST includes both $dir and $dir/$archname then $dir/$archname will | |
90 | be added to @INC twice (if $dir/$archname/auto exists). | |
91 | ||
e50aee73 AD |
92 | =head2 DELETING DIRECTORIES FROM @INC |
93 | ||
94 | You should normally only add directories to @INC. If you need to | |
95 | delete directories from @INC take care to only delete those which you | |
96 | added yourself or which you are certain are not needed by other modules | |
97 | in your script. Other modules may have added directories which they | |
98 | need for correct operation. | |
99 | ||
100 | By default the C<no lib> statement deletes the I<first> instance of | |
101 | each named directory from @INC. To delete multiple instances of the | |
102 | same name from @INC you can specify the name multiple times. | |
103 | ||
104 | To delete I<all> instances of I<all> the specified names from @INC you can | |
105 | specify ':ALL' as the first parameter of C<no lib>. For example: | |
106 | ||
107 | no lib qw(:ALL .); | |
108 | ||
4633a7c4 LW |
109 | For each directory in LIST (called $dir here) the lib module also |
110 | checks to see if a directory called $dir/$archname/auto exists. | |
111 | If so the $dir/$archname directory is assumed to be a corresponding | |
112 | architecture specific directory and is also deleted from @INC. | |
113 | ||
114 | If LIST includes both $dir and $dir/$archname then $dir/$archname will | |
115 | be deleted from @INC twice (if $dir/$archname/auto exists). | |
116 | ||
e50aee73 AD |
117 | =head2 RESTORING ORIGINAL @INC |
118 | ||
119 | When the lib module is first loaded it records the current value of @INC | |
120 | in an array C<@lib::ORIG_INC>. To restore @INC to that value you | |
4633a7c4 | 121 | can say |
e50aee73 AD |
122 | |
123 | @INC = @lib::ORIG_INC; | |
124 | ||
e50aee73 AD |
125 | |
126 | =head1 SEE ALSO | |
127 | ||
af3dad46 | 128 | FindBin - optional module which deals with paths relative to the source file. |
e50aee73 AD |
129 | |
130 | =head1 AUTHOR | |
131 | ||
132 | Tim Bunce, 2nd June 1995. | |
133 | ||
134 | =cut | |
135 |