You have to perform some preinstallation as ROOT and as LDM user before. For more detail see the online guide
http://www.unidata.ucar.edu/software/ldm/ldm-current/basics/index.html#installation
Create the LDM user-account
This is, necessarily, a system-dependent operation. Consult with your system's administrator, if necessary.
Keep the following in mind when creating the account:
The name of the user should be "ldm".
The installation process is simpler if the LDM user's home-directory is on local disk.
Use a group ID that allows other non-LDM processes to write files (decoders, etc.). The McIDAS and GEMPAK users are often members of this group.
If the computer on which the LDM runs has firewall (alias, packet filtering) rules, then these rules must be configured to allow connections to and from the LDM. How this is done is operating-system specific, so you might have to consult with your system or network administrator.
In order for the LDM system to send data to a downstream LDM, the firewall rules must allow incoming TCP connections to the port on which the LDM server is listening (the default is 388). An example of ensuring this for firewall rules based on iptables(8) is the command
iptables -A INPUT -p tcp --dport 388 -j ACCEPT
Similarly, in order for the LDM to receive data from an upstream LDM, the firewall rules must allow outgoing TCP connections to the port on which the upstream LDM server is listening (the default is 388). Because most sites don't bother filtering outgoing connections, this configuration step is usually not necessary.
As the LDM user, add the following entries to the appropriate login profile-file of the LDM user's user-shell. The profile-file should be the one that the user-shell reads when it's a login shell (e.g., .bash_profile, .login).
SysManPath is the pathname for the manual-pages of the operating system (e.g., /usr/man or /usr/share/man). The MANPATH environment variable might already contain this path.
export PATH=$HOME/decoders:$HOME/util:$HOME/bin:$PATH
export MANPATH=$HOME/share/man:SysManPath
Don't forget to source the profile-file so that the modifications take effect. For example:
> . .bash_profile
The following assumes that you are familiar with both the LDM system and with autoconf-based package-installation. If you're not, then follow the long installation instructions in the next section. First, vet your build environment against the table of successful build environments and unsuccessful build environments. Choose a 64-bit environment if possible. Then, do the following:
> su - ldm
> wget ftp://ftp.unidata.ucar.edu/pub/ldm/ldm-6.11.6.tar.gz
> gunzip -c ldm-6.11.6.tar.gz | pax -r '-s:/:/src/:'
> rm ldm-6.11.6.tar.gz # optional
> cd ldm-6.11.6/src
> export PATH=... # if necessary
> ./configure --enable-logging=localn --localstatedir=/var/ldm/ --disable-max-size --with-noaaport --with-gribinsert CC=/usr/bin/gcc CFLAGS=-UNDEBUG >configure.log 2>&1
Password: ...
> make install >make.log 2>&1
> make clean # optional
NOTE: If you don't have the pax(1) utility, then use this command, instead:
> gunzip -c ldm-6.11.6.tar.gz | (mkdir -p ldm-6.11.6 && cd ldm-6.11.6 && tar -xf - && mv ldm-6.11.6 src)
Long Installation Instructions:
http://www.unidata.ucar.edu/software/ldm/ldm-current/basics/source-install-steps.html