Introduction to at
The at package provide delayed job execution
and batch processing. It is required for Linux Standards Base (LSB)
conformance.
![[Note]](../images/note.png)
Note
Development versions of BLFS may not build or run
some packages properly if LFS or dependencies have been updated
since the most recent stable versions of the books.
Package Information
at Dependencies
Required
An MTA
Optional
Linux-PAM-1.5.3
Editor Notes:
https://wiki.linuxfromscratch.org/blfs/wiki/at
Installation of at
Before building at, as the
root user you should create
the group and user atd which
will run the atd daemon:
groupadd -g 17 atd &&
useradd -d /dev/null -c "atd daemon" -g atd -s /bin/false -u 17 atd
Install at with the following
commands:
./configure --with-daemon_username=atd \
--with-daemon_groupname=atd \
SENDMAIL=/usr/sbin/sendmail \
--with-jobdir=/var/spool/atjobs \
--with-atspool=/var/spool/atspool \
--with-systemdsystemunitdir=/lib/systemd/system &&
make -j1
To test the results, issue: make test.
Now, as the root user:
make install docdir=/usr/share/doc/at-3.2.5 \
atdocdir=/usr/share/doc/at-3.2.5Configuring at
Config Files
/etc/at.allow and
/etc/at.deny determines who can submit jobs via at
or batch.
Linux PAM Configuration
If At has been built with
Linux PAM support, you need to create a
PAM configuration file, to get it working
correctly with BLFS.
Issue the following commands as the root user to create the configuration
file for Linux PAM:
cat > /etc/pam.d/atd << "EOF"
# Begin /etc/pam.d/atd
auth required pam_unix.so
account required pam_unix.so
password required pam_unix.so
session required pam_unix.so
# End /etc/pam.d/atd
EOF
Systemd Unit
To start the atd daemon at boot,
enable the previously installed systemd unit by
running the following command as the
root user:
systemctl enable atd