|
Re: Finding out how you were called...
by tadman (Prior) on Aug 07, 2001 at 01:07 UTC
|
As far as I can tell, $0 will give you something to work
with and from there you can figure out the rest. Based on my
limited testing:
- If the program was executed based on your $PATH, $0
will include the full pathname.
- If the program was executed explicitly, either by being
in the directory, or including a relative path, $0 is this
relative path
I think Perl is doing some fancy stuff to help you out there.
After all, things often show up in the process table as
having a "$0" of "perl foo" or "perl /path/to/foo",
which correlates to the above two scenarios.
In the event $0 does not include the full path for you,
you can always "guess" which one was called by going through
your $ENV{PATH} and testing each one:
my $my_path = $0;
foreach my $path (split(/:/, $ENV{PATH}))
{
$my_path = "$path/$0" if (-f "$path/$0");
}
Either way, I think the functionality you are looking for
is something like:
my ($called_name) = $0 =~ m#/([^/]+)$#;
{
no strict;
&{"mode_$called_name"}() if (defined &{"mode_$called_name"});
}
sub mode_foo
{
# If program is called as "foo"
}
sub mode_moo
{
# If program is called as "moo"
}
| [reply]
[d/l]
[select] |
|
|
| [reply]
[d/l] |
|
|
Don't feel bad. An entire module has sprung up based on this same misconception (and it was authored by some of the top Perl guys around). $0 is the name of the script, which Perl has to be able to open so Perl knows the correct path to it and doesn't hide it from you. argv[0] in the C code that implements Perl is "...perl" (not the script name) and may not have a full path and so $^X may not have a full path. See FindBin is broken (RE: How do I get the full path to the script executing?) for more.
-
tye
(but my friends call me "Tye")
| [reply]
[d/l] |
|
|
It would seem that Perl processes its own argv[0] to make
it all nice and easy for you to do what you want. This is
not something that happens all by itself in C programs. C
does, to a certain degree, leave you up to your own
devices. So, evaluating your path for a possible match is
something to consider doing, perhaps with strtok on
a copy of your $PATH.
| [reply]
[d/l] |
Re: Finding out how you were called...
by busunsl (Vicar) on Aug 07, 2001 at 10:14 UTC
|
Have a look at the FindBin module.
It will give you the called program or the real program with all links resolved. | [reply] |
Re: Finding out how you were called...
by rchiav (Deacon) on Aug 06, 2001 at 23:41 UTC
|
$0 stores the name that the program was run as..
Either I completely misread the question or you added the bit about $0 after I wrote this :)
$0 (for me, on RH 7.1) contains the full path even if the script is in the path. The only time it doesn't is if I specify a relative path from the command line. An option could be to check, if it doesn't match the full path, if $0 and the pwd eq what you're looking for.
Rich | [reply] |
|
|
Since I can't edit SOPW posts... :)
what I need is the command that was called, including the directory of it...
- Ant
- Some of my best work - Fish Dinner
| [reply] |
|
|
| [reply] |
|
|
wierd.. I have RH 7.1 with bash (perl 5.61). Here's my test
#!/usr/bin/perl -w
print " I was called as $0\n";
results as follows. tt is the original file. rr is a symlink in /usr/local/bin
[xxxx@yyy:/home/xxxx]$ tt
I was called as ./tt
[xxxx@yyy:/home/xxxx]$ rr
I was called as /usr/local/bin/rr
[xxxx@yyy:/home/xxxx]$
| [reply]
[d/l]
[select] |
|
|
Re: Finding out how you were called...
by princepawn (Parson) on Aug 06, 2001 at 23:35 UTC
|
| [reply]
[d/l] |
|
|
| [reply] |