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 | } |
20408e3c GS |
21 | if (-e && ! -d _) { |
22 | require Carp; | |
23 | Carp::carp("Parameter to use lib must be directory, not file"); | |
24 | } | |
4633a7c4 LW |
25 | unshift(@INC, $_); |
26 | # Put a corresponding archlib directory infront of $_ if it | |
27 | # looks like $_ has an archlib directory below it. | |
774d564b | 28 | if (-d "$_/$archname") { |
29 | unshift(@INC, "$_/$archname") if -d "$_/$archname/auto"; | |
30 | unshift(@INC, "$_/$archname/$]") if -d "$_/$archname/$]/auto"; | |
31 | } | |
4633a7c4 | 32 | } |
e50aee73 AD |
33 | } |
34 | ||
35 | ||
36 | sub unimport { | |
37 | shift; | |
38 | my $mode = shift if $_[0] =~ m/^:[A-Z]+/; | |
39 | ||
40 | my %names; | |
4633a7c4 LW |
41 | foreach(@_) { |
42 | ++$names{$_}; | |
43 | ++$names{"$_/$archname"} if -d "$_/$archname/auto"; | |
44 | } | |
e50aee73 AD |
45 | |
46 | if ($mode and $mode eq ':ALL') { | |
47 | # Remove ALL instances of each named directory. | |
48 | @INC = grep { !exists $names{$_} } @INC; | |
49 | } else { | |
50 | # Remove INITIAL instance(s) of each named directory. | |
51 | @INC = grep { --$names{$_} < 0 } @INC; | |
52 | } | |
53 | } | |
54 | ||
4633a7c4 | 55 | 1; |
e50aee73 AD |
56 | __END__ |
57 | ||
58 | =head1 NAME | |
59 | ||
60 | lib - manipulate @INC at compile time | |
61 | ||
62 | =head1 SYNOPSIS | |
63 | ||
64 | use lib LIST; | |
65 | ||
66 | no lib LIST; | |
67 | ||
68 | =head1 DESCRIPTION | |
69 | ||
70 | This is a small simple module which simplifies the manipulation of @INC | |
71 | at compile time. | |
72 | ||
73 | It is typically used to add extra directories to perl's search path so | |
74 | that later C<use> or C<require> statements will find modules which are | |
75 | not located on perl's default search path. | |
76 | ||
e50aee73 AD |
77 | =head2 ADDING DIRECTORIES TO @INC |
78 | ||
79 | The parameters to C<use lib> are added to the start of the perl search | |
80 | path. Saying | |
81 | ||
82 | use lib LIST; | |
83 | ||
4633a7c4 | 84 | is I<almost> the same as saying |
e50aee73 AD |
85 | |
86 | BEGIN { unshift(@INC, LIST) } | |
87 | ||
4633a7c4 LW |
88 | For each directory in LIST (called $dir here) the lib module also |
89 | checks to see if a directory called $dir/$archname/auto exists. | |
90 | If so the $dir/$archname directory is assumed to be a corresponding | |
91 | architecture specific directory and is added to @INC in front of $dir. | |
92 | ||
93 | If LIST includes both $dir and $dir/$archname then $dir/$archname will | |
94 | be added to @INC twice (if $dir/$archname/auto exists). | |
95 | ||
e50aee73 AD |
96 | =head2 DELETING DIRECTORIES FROM @INC |
97 | ||
98 | You should normally only add directories to @INC. If you need to | |
99 | delete directories from @INC take care to only delete those which you | |
100 | added yourself or which you are certain are not needed by other modules | |
101 | in your script. Other modules may have added directories which they | |
102 | need for correct operation. | |
103 | ||
104 | By default the C<no lib> statement deletes the I<first> instance of | |
105 | each named directory from @INC. To delete multiple instances of the | |
106 | same name from @INC you can specify the name multiple times. | |
107 | ||
108 | To delete I<all> instances of I<all> the specified names from @INC you can | |
109 | specify ':ALL' as the first parameter of C<no lib>. For example: | |
110 | ||
111 | no lib qw(:ALL .); | |
112 | ||
4633a7c4 LW |
113 | For each directory in LIST (called $dir here) the lib module also |
114 | checks to see if a directory called $dir/$archname/auto exists. | |
115 | If so the $dir/$archname directory is assumed to be a corresponding | |
116 | architecture specific directory and is also deleted from @INC. | |
117 | ||
118 | If LIST includes both $dir and $dir/$archname then $dir/$archname will | |
119 | be deleted from @INC twice (if $dir/$archname/auto exists). | |
120 | ||
e50aee73 AD |
121 | =head2 RESTORING ORIGINAL @INC |
122 | ||
123 | When the lib module is first loaded it records the current value of @INC | |
124 | in an array C<@lib::ORIG_INC>. To restore @INC to that value you | |
4633a7c4 | 125 | can say |
e50aee73 AD |
126 | |
127 | @INC = @lib::ORIG_INC; | |
128 | ||
e50aee73 AD |
129 | |
130 | =head1 SEE ALSO | |
131 | ||
af3dad46 | 132 | FindBin - optional module which deals with paths relative to the source file. |
e50aee73 AD |
133 | |
134 | =head1 AUTHOR | |
135 | ||
136 | Tim Bunce, 2nd June 1995. | |
137 | ||
138 | =cut | |
139 |