## E.6 Used environment variables

SINGULAR needs to find some files (dynamic modules, libraries, help files). Usually they are found relative to the location of the (main) executable (after following symlinks). This can be changed by setting the following environment variables.

- SINGULAR_EXECUTABLE (should usually not be set)
  the complete filename of the main executable, usually derived from the command line (inspecting also PATH, following symlinks).
  If SINGULAR_EXECUTABLE cannot be found, $prefix/bin/Singular is assumed.
  For `libSingular`: SINGULAR_EXECUTABLE is set to the argument of `siInit` (it must exist).
- SINGULAR_BIN_DIR
  the directory of the main executable, usually derived from $SINGULAR_EXECUTABLE
- SINGULAR_ROOT_DIR
  the root of the singular tree, default: $SINGULAR_BIN_DIR/..
- SINGULAR_DATA_DIR
  the root of the singular data files, default: $SINGULAR_BIN_DIR/../share
- SINGULARPATH
  the directories for libraries and optional dynamic modules (separated by `;`), default:
  - $SINGULAR_DATA_DIR/singular/LIB
  - $SINGULAR_ROOT_DIR/share/singular/LIB
  - $SINGULAR_BIN_DIR/../share/singular/LIB
  - $SINGULAR_DATA_DIR/factory
  - $SINGULAR_ROOT_DIR/share/factory
  - $SINGULAR_BIN_DIR/LIB
  - $SINGULAR_BIN_DIR/../factory
  - $SINGULAR_BIN_DIR/MOD
  - $SINGULAR_ROOT_DIR/lib/singular/MOD
  - $SINGULAR_ROOT_DIR/libexec/singular/MOD
  - $prefix/lib/singular/MOD
  - $prefix/libexec/singular/MOD
  - $SINGULAR_BIN_DIR
- SINGULAR_PROCS_DIR
  the directories for dynamic modules (separated by `;`), default:
  - $SINGULAR_BIN_DIR/MOD
  - $SINGULAR_ROOT_DIR/lib/singular/MOD
  - $SINGULAR_ROOT_DIR/libexec/singular/MOD
  - $prefix/lib/singular/MOD
  - $prefix/libexec/singular/MOD
- SINGULAR_INFO_FILE
  `singular.info`, default: $SINGULAR_DATA_DIR/info/singular.info
- SINGULAR_IDX_FILE
  the help index, default: $SINGULAR_DATA_DIR/singular/singular.idx
- SINGULAR_HTML_DIR
  the directory of the manual as html files, default: $SINGULAR_DATA_DIR/singular/html
- SINGULAR_URL
  the URL of the manual, default: https://www.singular.uni-kl.de/Manual/
- SINGULAR_CPUS maximal number of cpu cores to use, default: all available
  can also be given by a command line argument: `--cpus=...`

The effective list of directories/files can be printed by `Singular -v`, see Command line options.

Depending on the used functions, these environment variables apply also to `libSingular`.

User manual for Singular version 4.4.1, 2025, generated by texi2html.