| 1 | NAME |
1 | NAME |
| 2 | Guard - safe cleanup blocks |
2 | Guard - safe cleanup blocks |
| 3 | |
3 | |
| 4 | SYNOPSIS |
4 | SYNOPSIS |
| 5 | use Guard; |
5 | use Guard; |
| 6 | |
6 | |
| 7 | # temporarily chdir to "/etc" directory, but make sure |
7 | # temporarily chdir to "/etc" directory, but make sure |
| 8 | # to go back to "/" no matter how myfun exits: |
8 | # to go back to "/" no matter how myfun exits: |
| 9 | sub myfun { |
9 | sub myfun { |
| 10 | scope_guard { chdir "/" }; |
10 | scope_guard { chdir "/" }; |
| 11 | chdir "/etc"; |
11 | chdir "/etc"; |
| 12 | |
12 | |
| 13 | code_that_might_die_or_does_other_fun_stuff; |
13 | code_that_might_die_or_does_other_fun_stuff; |
| 14 | } |
14 | } |
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15 | |
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16 | # create an object that, when the last reference to it is gone, |
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17 | # invokes the given codeblock: |
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18 | my $guard = guard { print "destroyed!\n" }; |
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19 | undef $guard; # probably destroyed here |
| 15 | |
20 | |
| 16 | DESCRIPTION |
21 | DESCRIPTION |
| 17 | This module implements so-called "guards". A guard is something (usually |
22 | This module implements so-called "guards". A guard is something (usually |
| 18 | an object) that "guards" a resource, ensuring that it is cleaned up when |
23 | an object) that "guards" a resource, ensuring that it is cleaned up when |
| 19 | expected. |
24 | expected. |
