Help: Variables problem

[Amy Lee]

Hello,

I'm writing a script to parse the contents of /proc/loadavg file. And the
file is like this:

0.22 0.11 0.03 1/92 2653

And I hope my script output is like this:

1 minute loadavg: 0.22
5 minutes loadavg: 0.11
10 minutes loadavg: 0.03
Running processes: 1 processes
Total processes: 92 processes

And there's my codes:

open LOADAVG, "<", "/proc/loadavg"
or die RED "Can't open /proc/loadavg. $!";
while (<LOADAVG>)
{
<LOADAVG> =~ /(\d+)\.(\d+)\s+(\d+)\.(\d+)\s+(\d+)\.(\d+)\s+(\d+)\/(\d+)\s+\d+/;
print "1 minute loadavg: $1.$2\n";
print "5 minutes loadavg: $3.$4\n";
print "10 minutes loadavg: $5.$6\n";
print "Running processes: $7 processes\n";
print "Total processes: $8 processes\n";
}
close LOADAVG;

But when I excute this codes such errors shows:

Use of uninitialized value in concatenation (.) or string at ./soms.pl line 16, <LOADAVG> line 1.
Use of uninitialized value in concatenation (.) or string at ./soms.pl line 16, <LOADAVG> line 1.
1 minute loadavg: .
Use of uninitialized value in concatenation (.) or string at ./soms.pl line 17, <LOADAVG> line 1.
Use of uninitialized value in concatenation (.) or string at ./soms.pl line 17, <LOADAVG> line 1.
5 minutes loadavg: .
Use of uninitialized value in concatenation (.) or string at ./soms.pl line 18, <LOADAVG> line 1.
Use of uninitialized value in concatenation (.) or string at ./soms.pl line 18, <LOADAVG> line 1.
10 minutes loadavg: .
Use of uninitialized value in concatenation (.) or string at ./soms.pl line 19, <LOADAVG> line 1.
Running processes: processes
Use of uninitialized value in concatenation (.) or string at ./soms.pl line 20, <LOADAVG> line 1.
Total processes: processes

Could you tell me what happens? And how to fix it.

Huge thanks!

Best Regards,

Amy

 

[Peter Makholm]

And there's my codes:

open LOADAVG, "<", "/proc/loadavg"
or die RED "Can't open /proc/loadavg. $!";

On my system this pseudo file consists of one and only one line

while (<LOADAVG>)

Which you read into $_ here.

{
<LOADAVG> =~ /(\d+)\.(\d+)\s+(\d+)\.(\d+)\s+(\d+)\.(\d+)\s+(\d+)\/(\d+)\s+\d+/;

As you allready has read the only line in the file this read opration
returns undef. So what you actually do is to try to match on the
undefined string. This fails of course and thus leaves $1 to $9
undefined.

Could you tell me what happens? And how to fix it.

Try matching the line you just read instead of matching on the next
line.

//Makholm

 

[Amy Lee]

On my system this pseudo file consists of one and only one line


Which you read into $_ here.


As you allready has read the only line in the file this read opration
returns undef. So what you actually do is to try to match on the
undefined string. This fails of course and thus leaves $1 to $9
undefined.


Try matching the line you just read instead of matching on the next
line.

//Makholm

Huge thanks to you, I have solved this one.

Amy

 

[Ted Zlatanov]

AL> I'm writing a script to parse the contents of /proc/loadavg file. And the
AL> file is like this:

AL> 0.22 0.11 0.03 1/92 2653

AL> And I hope my script output is like this:

AL> 1 minute loadavg: 0.22
AL> 5 minutes loadavg: 0.11
AL> 10 minutes loadavg: 0.03
AL> Running processes: 1 processes
AL> Total processes: 92 processes

AL> And there's my codes:

AL> open LOADAVG, "<", "/proc/loadavg"
AL> or die RED "Can't open /proc/loadavg. $!";
AL> while (<LOADAVG>)
AL> {
AL> <LOADAVG> =~ /(\d+)\.(\d+)\s+(\d+)\.(\d+)\s+(\d+)\.(\d+)\s+(\d+)\/(\d+)\s+\d+/;
AL> print "1 minute loadavg: $1.$2\n";
AL> print "5 minutes loadavg: $3.$4\n";
AL> print "10 minutes loadavg: $5.$6\n";
AL> print "Running processes: $7 processes\n";
AL> print "Total processes: $8 processes\n";
AL> }
AL> close LOADAVG;

Use the split ' ' syntax to get individual fields (you'll need a further
split for field 4, of course). You can also consider Regexp::Common to
extract numbers.

Or install the CPAN Linux::loadavg module.

Ted

 

[Amy Lee]

AL> I'm writing a script to parse the contents of /proc/loadavg file. And the
AL> file is like this:

AL> 0.22 0.11 0.03 1/92 2653

AL> And I hope my script output is like this:

AL> 1 minute loadavg: 0.22
AL> 5 minutes loadavg: 0.11
AL> 10 minutes loadavg: 0.03
AL> Running processes: 1 processes
AL> Total processes: 92 processes

AL> And there's my codes:

AL> open LOADAVG, "<", "/proc/loadavg"
AL> or die RED "Can't open /proc/loadavg. $!";
AL> while (<LOADAVG>)
AL> {
AL> <LOADAVG> =~ /(\d+)\.(\d+)\s+(\d+)\.(\d+)\s+(\d+)\.(\d+)\s+(\d+)\/(\d+)\s+\d+/;
AL> print "1 minute loadavg: $1.$2\n";
AL> print "5 minutes loadavg: $3.$4\n";
AL> print "10 minutes loadavg: $5.$6\n";
AL> print "Running processes: $7 processes\n";
AL> print "Total processes: $8 processes\n";
AL> }
AL> close LOADAVG;

Use the split ' ' syntax to get individual fields (you'll need a further
split for field 4, of course). You can also consider Regexp::Common to
extract numbers.

Or install the CPAN Linux::loadavg module.

Ted

Thanks, it seems that your method id pretty good.

Regards,
Amy