mail command of unix

I am using the开发者_开发技巧 mail command of unix in a perl script. I specify the 'to', 'cc', 'subject' and 'body' of the mail. I do not specify the from address. Where is the from address picked from? Pls help

There are portable libraries for handling email as daxim and David W mention, but if you want a quick fix, this works under linux if your mail command uses bsd-mailx (as it does on my machine)...

#!/usr/bin/env perl

$BODY = "Hello self";
$RECIPIENT = "destination\@email.local";
$FROM = "mike\@localhost";
$SUBJECT = "some subject here";
$CMD = qq(echo "$BODY" | mail -a "From: $FROM" -s $SUBJECT $RECIPIENT);
exec($CMD);

If you have more questions about the unix mail command, try man mail from your shell prompt.

The mail command on most system nowadays is Heirloom mailx. It claims compatibility with POSIX, so the information I give here should be good for any well-behaving mail command.

The From address is set by:

• either the user@domain as returned by the appropriate POSIX system calls (see shell commands whoami and domainname -f for a different way to access them)
• or set by the from environment variable
• or set by the -r command line option (going to be deprecated?)

Obligatory Clippy: Hi! I see you are trying to send mail from Perl. Did you mean to use Email::Sender/Email::Simple instead?

Don't use the mail command linecommand! Use Net::SMTP.

The mail command may not even be configured on a particular system, and it won't work on Windows. Meanwhile, Net::SMTP is a standard Perl module that should be available on all systems.

Never used it before? Read the documentation and try it out. That's how you learn.