Set up a shell with the environment

Source setEpicsEnv.bash from the top of an installed tree to point the current Bash shell at that tree’s Experimental Physics and Industrial Control System (EPICS) base, modules, and tools.

Prerequisites

• An installed tree built with make install and make symlinks; see Build and install the environment. The script puts the pvxs and pmac tools on PATH through the unversioned module links that make symlinks creates.
• perl on PATH for automatic architecture detection, or a fallback architecture supplied as described in step 3.

1. Source the script of the installed tree:

   source <installed_tree>/setEpicsEnv.bash
   

   <installed_tree> is the path that make print-INSTALL_LOCATION_EPICS prints in the EPICS-env clone that built the tree.

   The script prints a summary of the values it set, followed by the full PATH and LD_LIBRARY_PATH and the line Enjoy Everlasting EPICS!. The summary starts with these lines:

   
   Set the EPICS Environment as follows:
   THIS Source NAME    : setEpicsEnv.bash
   THIS Source PATH    : <installed_tree>
   EPICS_BASE          : <installed_tree>/base
   EPICS_HOST_ARCH     : linux-x86_64
   EPICS_MODULES       : <installed_tree>/modules
   

   The script derives every path from its own location, so it needs no edit when the tree moves. To select another installed version, source that tree’s setup script. No location or release argument is required. It exports these variables:

   Variable	Value
   EPICS_PATH	The directory that holds the script
   EPICS_BASE	$EPICS_PATH/base
   EPICS_MODULES	$EPICS_PATH/modules
   EPICS_HOST_ARCH	The detected architecture, such as linux-x86_64, or the supplied fallback
   PATH	Prepends modules/pmac/bin/<arch>, modules/pvxs/bin/<arch>, and base/bin/<arch>
   LD_LIBRARY_PATH	Prepends base/lib/<arch>

   <arch> is the value of EPICS_HOST_ARCH. When EPICS_BASE is set before you source the script, the script first prints EPICS_BASE is defined as with that value. It then removes the entries of that tree from PATH and LD_LIBRARY_PATH and adds the entries of the sourced tree. Sourcing a second tree therefore replaces the known base, pvxs, and pmac paths of the first. Removal compares complete colon-delimited entries. Unrelated entries retain their bytes and order, including duplicates and empty entries. Repeating setup adds each managed directory once.

   Setup preserves independent settings such as EPICS_CA_ADDR_LIST and EPICS_CA_AUTO_ADDR_LIST. It also works with Bash nounset enabled by set -u, and preserves the caller’s directory, shell options, and positional arguments.

2. Optional: to set the same variables without the printed summary, pass disable:

   source <installed_tree>/setEpicsEnv.bash disable
   

   In the shell of step 1, EPICS_BASE is set, so the script prints the tree that it replaces, followed by two empty lines:

   
   EPICS_BASE is defined as <installed_tree>/base
   
   
   

   In a shell where EPICS_BASE is not set, the script prints one empty line.

3. Optional: supply a fallback architecture when Perl or the base discovery scripts are unavailable:

   source <installed_tree>/setEpicsEnv.bash linux-x86_64 disable
   

   The interface is [<fallback_arch>] [disable]. Automatic detection takes priority over the fallback. disable controls only the summary. Invalid argument forms return status 2. If the script cannot determine its tree or architecture, it returns status 1 with a diagnostic and preserves the existing managed environment. A discovery command that fails returns status 1 before the script replaces that environment.

4. Optional: remove the environment from the shell by sourcing the installed reset script:

   source <installed_tree>/resetEpicsEnv.bash
   

   The output names the tree it removes:

   
   EPICS_BASE is defined as <installed_tree>/base
   
   Reset ...
   

   The script removes the base, pvxs, and pmac entries from PATH, the base entry from LD_LIBRARY_PATH, and unsets EPICS_PATH, EPICS_BASE, EPICS_HOST_ARCH, and EPICS_MODULES. It also removes the known legacy extension executable entry and unsets EPICS_EXTENSIONS. Missing path components prevent removal of the corresponding entry; variable unsetting also runs when base is absent. Repeated reset succeeds.

   Reset preserves independent CA settings and other unmanaged EPICS variables. install.base installs both setup and reset with mode 0644.

Verification

• Check that the shell finds the EPICS tools in the installed tree:

  command -v softIoc caget pvget pvxget
  

  Each tool resolves inside <installed_tree>:

  <installed_tree>/base/bin/linux-x86_64/softIoc
  <installed_tree>/base/bin/linux-x86_64/caget
  <installed_tree>/base/bin/linux-x86_64/pvget
  <installed_tree>/modules/pvxs/bin/linux-x86_64/pvxget