October 2007
Intermediate to advanced
1308 pages
161h 13m
English
Content preview from sendmail, 4th EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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-d52.1
Show disconnect from controlling TTY Debug command-line switch
When sendmail runs as a daemon, it must disconnect itself from the terminal device that is used to run it. This prevents keyboard signals from killing it and prevents it from hanging (on a dial-in line waiting for carrier detect, for example).
The -d52.1 (a.k.a.
-d52) debugging
switch shows sendmail
disconnecting from the controlling terminal
device:
disconnect: In fd Out fd, e=addr
For both its input and output connections, the
fd is a decimal
representation of the file descriptor number. The
addr is a hexadecimal
representation of the address that contains the
envelope information. If the LogLevel option (LogLevel on page 1040) is greater than
71, sendmail syslog(3)s the
following message to show that it has
disconnected:
in background, pid=pidHere, pid is the process identification number of the child process (the daemon).
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.