3 use vars qw(@ORIG_INC);
6 my $archname = $Config{'archname'};
8 @ORIG_INC = @INC; # take a handy copy of 'original' value
15 foreach (reverse @_) {
18 Carp::carp("Empty compile time value given to use lib");
22 Carp::carp("Parameter to use lib must be directory, not file");
25 # Put a corresponding archlib directory infront of $_ if it
26 # looks like $_ has an archlib directory below it.
27 if (-d "$_/$archname") {
28 unshift(@INC, "$_/$archname") if -d "$_/$archname/auto";
29 unshift(@INC, "$_/$archname/$]") if -d "$_/$archname/$]/auto";
33 # remove trailing duplicates
34 @INC = grep { ++$names{$_} == 1 } @INC;
45 ++$names{"$_/$archname"} if -d "$_/$archname/auto";
48 # Remove ALL instances of each named directory.
49 @INC = grep { !exists $names{$_} } @INC;
58 lib - manipulate @INC at compile time
68 This is a small simple module which simplifies the manipulation of @INC
71 It is typically used to add extra directories to perl's search path so
72 that later C<use> or C<require> statements will find modules which are
73 not located on perl's default search path.
75 =head2 Adding directories to @INC
77 The parameters to C<use lib> are added to the start of the perl search
82 is I<almost> the same as saying
84 BEGIN { unshift(@INC, LIST) }
86 For each directory in LIST (called $dir here) the lib module also
87 checks to see if a directory called $dir/$archname/auto exists.
88 If so the $dir/$archname directory is assumed to be a corresponding
89 architecture specific directory and is added to @INC in front of $dir.
91 To avoid memory leaks, all trailing duplicate entries in @INC are
94 =head2 Deleting directories from @INC
96 You should normally only add directories to @INC. If you need to
97 delete directories from @INC take care to only delete those which you
98 added yourself or which you are certain are not needed by other modules
99 in your script. Other modules may have added directories which they
100 need for correct operation.
102 The C<no lib> statement deletes all instances of each named directory
105 For each directory in LIST (called $dir here) the lib module also
106 checks to see if a directory called $dir/$archname/auto exists.
107 If so the $dir/$archname directory is assumed to be a corresponding
108 architecture specific directory and is also deleted from @INC.
110 =head2 Restoring original @INC
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
116 @INC = @lib::ORIG_INC;
121 FindBin - optional module which deals with paths relative to the source file.
125 Tim Bunce, 2nd June 1995.