I probably wasn't too clear. The function that I'm trying
to test for resides in a Perl script that begins with:
#! /usr/bin/perl.
So I would assume that I can't do a "require" or "use"
on it and then test for the function name using $package::func.
The reason I need to do this is because I have a lot of
Perl scripts written/maintained by someone else. I would
like to pull them unmodified into my test harness and
execute functions inside them without having to modify
the code.
Hope this clears it up and thanks for all the help.
-brad w. | [reply] [d/l] [select] |
Actually, you can require them. However, if there is any code inside that isn't wrapped in a sub, it will execute when the file is required. Example:
#!/usr/bin/perl
### the file doing the requiring
use strict;
use warnings;
use lib '/path/to/lib';
require('tmp.pl');
asdf();
---
#!/usr/bin/perl
### the file being required
use strict;
use warnings;
print "hi there\n";
sub asdf { print "well howdy"; }
1;
---
### the output
hi there
well howdy
---
It's all fine and dandy until someone has to look at the code.
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Ok, so if I understand, you've got a script running, and within one of its used modules you wish to probe a completely different script to see if a particular function exists. Is that right?
Maybe you should search for that sub's name in the output from B::Xref.
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That is correct..
-brad w.
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Congratulations, you are re-inventing the Perl4 idiom for including subroutine libraries! From perlfunc
do EXPR
Uses the value of EXPR as a filename and executes the contents of the file as a Perl script.
do 'stat.pl';
is just like
eval `cat stat.pl`;
except that it's more efficient and concise, keeps track of the current filename for error messages, searches the @INC directories, and updates %INC if the file is found. See Predefined Names in the perlvar manpage for these variables. It also differs in that code evaluated with do FILENAME cannot see lexicals in the enclosing scope; eval STRING does. It's the same, however, in that it does reparse the file every time you call it, so you probably don't want to do this inside a loop.
If do cannot read the file, it returns undef and sets $! to the error. If do can read the file but cannot compile it, it returns undef and sets an error message in $@. If the file is successfully compiled, do returns the value of the last expression evaluated.
Note that inclusion of library modules is better done with the use and require operators, which also do automatic error checking and raise an exception if there's a problem.
You might like to use do to read in a program configuration file. Manual error checking can be done this way:
# read in config files: system first, then user
for $file ("/share/prog/defaults.rc",
"$ENV{HOME}/.someprogrc")
{
unless ($return = do $file) {
warn "couldn't parse $file: $@" if $@;
warn "couldn't do $file: $!" unless defined $return
+;
warn "couldn't run $file" unless $return;
}
}
CountZero "If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law
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