3 use vars qw(@ORIG_INC);
6 my $archname = $Config{'archname'};
7 my $ver = $Config{'version'};
9 @ORIG_INC = @INC; # take a handy copy of 'original' value
16 foreach (reverse @_) {
19 Carp::carp("Empty compile time value given to use lib");
23 Carp::carp("Parameter to use lib must be directory, not file");
26 # Put a corresponding archlib directory infront of $_ if it
27 # looks like $_ has an archlib directory below it.
28 if (-d "$_/$archname") {
29 unshift(@INC, "$_/$archname") if -d "$_/$archname/auto";
30 unshift(@INC, "$_/$archname/$ver") if -d "$_/$archname/$ver/auto";
34 # remove trailing duplicates
35 @INC = grep { ++$names{$_} == 1 } @INC;
46 ++$names{"$_/$archname"} if -d "$_/$archname/auto";
49 # Remove ALL instances of each named directory.
50 @INC = grep { !exists $names{$_} } @INC;
59 lib - manipulate @INC at compile time
69 This is a small simple module which simplifies the manipulation of @INC
72 It is typically used to add extra directories to perl's search path so
73 that later C<use> or C<require> statements will find modules which are
74 not located on perl's default search path.
76 =head2 Adding directories to @INC
78 The parameters to C<use lib> are added to the start of the perl search
83 is I<almost> the same as saying
85 BEGIN { unshift(@INC, LIST) }
87 For each directory in LIST (called $dir here) the lib module also
88 checks to see if a directory called $dir/$archname/auto exists.
89 If so the $dir/$archname directory is assumed to be a corresponding
90 architecture specific directory and is added to @INC in front of $dir.
92 To avoid memory leaks, all trailing duplicate entries in @INC are
95 =head2 Deleting directories from @INC
97 You should normally only add directories to @INC. If you need to
98 delete directories from @INC take care to only delete those which you
99 added yourself or which you are certain are not needed by other modules
100 in your script. Other modules may have added directories which they
101 need for correct operation.
103 The C<no lib> statement deletes all instances of each named directory
106 For each directory in LIST (called $dir here) the lib module also
107 checks to see if a directory called $dir/$archname/auto exists.
108 If so the $dir/$archname directory is assumed to be a corresponding
109 architecture specific directory and is also deleted from @INC.
111 =head2 Restoring original @INC
113 When the lib module is first loaded it records the current value of @INC
114 in an array C<@lib::ORIG_INC>. To restore @INC to that value you
117 @INC = @lib::ORIG_INC;
122 FindBin - optional module which deals with paths relative to the source file.
126 Tim Bunce, 2nd June 1995.