Needing help with the linux mail command

HyperTrey · 06-10-2008, 08:07 AM

over the past month or so, I do have to thank all of you for your tremendous help that you have given me in Perl and Shell scripting. I have learned tons and I look forward to being just as helpful to others as well.
In fact I am steadily rewriting shell codes we have to Perl so that I may further my knowledge of it. The Perl scripts that I have been editing have been done by someone a long time ago that is no longer employed.

The new problem on the same script is the shell command of mail. The script does what it supposed to do of creating a list of users and their stats and then creating a list of printer and their stats without breaking code or needing two different scripts. I managed to do it with sub routines however I have noticed that when I try to use the

Code:

exec("$home/bin/test /<path>/$f | mail -s \"$h\" prn-testing");

where $f is the log file (which changes ever month) and the $h is the subject. It will only email the first half of what is printed to the screen. How do I solve this without writing it to a file and then emailing the file? This server, however powerful, the powers to be do not want anything else installed such as modules and such. All this has been done the long way and some ways via shell calls using system and exec. If I end up have to write a file, how do I write the file on a temp bases and when it gets mailed, erase it?

theriddle · 06-10-2008, 10:38 AM

I think (it's doing this on my system) that the second half is being sent to the CC (carbon copy).

On my system, when I type "mail -s test <my-user>"

Code:

$ mail -s test <my-user>
test
^D
Cc:

To fix:

Code:

$ sendmail <my-user>
Subject: test
test
^D

Or in perl (using proper Perl IPC):

Code:

open(LOG,"$home/bin/test /<path>/$f|");
open(MAIL,"|sendmail prn-testing");
print MAIL "Subject: $h\n";
while (<LOG>) {
        print MAIL "$_\n";
}
close(LOG);
close(MAIL);

theriddle · 06-10-2008, 10:44 AM

Oh, and 2 last-minute mentions:
1) Since the log is now going through the perl script, you can pre-process it like so:

Code:

while (<LOG>) {
  if (/some_regular_expression/) {
    print MAIL "$_\n";
  }
}

2) sendmail (as the man page mentions) is meant for these types of tasks.

HyperTrey · 06-10-2008, 11:53 AM

so the I can invoke it like

Code:

exec("$home/bin/test /<path>/$f | sendmail \"$h\" prn-testing");

where it will run the script and the pipe that output via the send mail or does the send mail have to be in the place of the write command?

IE:

Code:

sub writeUR {
        for (sort { $tot_page_count{$a}<=>$tot_page_count{$b} } (keys(%tot_page_count)))  {
                $tax = $totals{$uname} * .06;
                $~ = "STDOUT";
                write;  (where the print MAIL "$_\n"; would be here)
        }
}

HyperTrey · 06-10-2008, 12:14 PM

actually I get this:

print@papyrus:~/bin> sendmail
-bash: sendmail: command not found
print@papyrus:~/bin>

theriddle · 06-10-2008, 12:15 PM

Quote:

Originally Posted by HyperTrey

so the I can invoke it like

Code:

exec("$home/bin/test /<path>/$f | sendmail \"$h\" prn-testing");

where it will run the script and the pipe that output via the send mail or does the send mail have to be in the place of the write command?

No. sendmail expects the headers (like Subject) to be in the message itself in the form of "Name: value".
As a (drop-in) example:

Code:

exec("/bin/echo -e \"Subject: $h\\n`$home/bin/test /<path>/$f`\" | sendmail prn-testing");

However, this:

Code:

open(LOG,"$home/bin/test /<path>/$f|");
open(MAIL,"|sendmail prn-testing");
print MAIL "Subject: $h\n";
while (<LOG>) {
        print MAIL "$_\n";
}
close(LOG);
close(MAIL);

while being slightly larger, uses more Perl constructs than shell ones, and is easier to understand.

theriddle · 06-10-2008, 12:25 PM

Quote:

Originally Posted by HyperTrey

actually I get this:

print@papyrus:~/bin> sendmail
-bash: sendmail: command not found
print@papyrus:~/bin>

Try /usr/lib/sendmail.

Do you have a MTA on the system at all?

HyperTrey · 06-10-2008, 01:19 PM

I could not get the sendmail to work. It seems to be in the /usr/lib folder however it hangs almost every time and the other times it just did nothing. I solved the problem by just redirecting the output to a temp file and then removing the temp file as the script is done.

theriddle · 06-10-2008, 01:30 PM

Quote:

Originally Posted by HyperTrey

I could not get the sendmail to work. It seems to be in the /usr/lib folder however it hangs almost every time and the other times it just did nothing. I solved the problem by just redirecting the output to a temp file and then removing the temp file as the script is done.

sendmail is supposed to "hang". Type out the message and press ^D (control+d). Is the MTA on the same system you're sending from (that would explain the hang).

To add a subject, run sendmail like this.

Code:

$ sendmail <to>
Subject: <sub>
<msg>
^D