---
name: "gap"
section: "1"
platform: "linux"
package: "gap-core"
version: "4.14.0-3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/gap"
---

# gap(1)

Groups, Algorithms and Programming

## NAME

GAP - Groups, Algorithms and Programming

## SYNOPSIS

**gap** \[*OPTIONS*\] \[*FILES*\]

## DESCRIPTION

GAP is a system for computational discrete algebra, with particular emphasis on Computational Group Theory. GAP provides a programming language, a library of thousands of functions implementing algebraic algorithms written in the GAP language as well as large data libraries of algebraic objects. GAP is used in research and teaching for studying groups and their representations, rings, vector spaces, algebras, combinatorial structures, and more.

### Startup:

- **-h**, **--help**

  print this help and exit

- **--version**

  print the GAP version and exit

- **--print-gaproot**

  print the primary GAP root and exit

- **-b**, **--banner**

  disable/enable the banner

- **-c**

  \<expr\>    execute the expression \<expr\>

- **--systemfile**

  \<file\>    read this file after 'lib/system.g'

### Input/output:

- **-q**, **--quiet**

  enable/disable quiet mode

- **-e**

  disable/enable quitting on \<ctrl\>-D

- **-f**

  force line editing

- **-n**

  prevent line editing

- **-E**, **--readline**

  disable/enable use of readline library (if possible)

- **-x**, **--width**

  \<num\>     set line width

- **-y**, **--lines**

  \<num\>     set number of lines

- **-p**

  enable/disable package output mode (for use by XGAP and similar interfaces)

### Memory:

-

  (may use postfix 'k' = \*1024, 'm' = \*1024\*1024,

-

  'g' = \*1024\*1024\*1024):

- **-g**, **--gasinfo**

  show GASMAN messages (full/all/no garbage collections) (only available if GAP uses GASMAN)

- **-m**, **--minworkspace**

  \<mem\>     set the initial workspace size

- **-o**, **--maxworkspace**

  \<mem\>     set workspace size where GAP will warn about excessive memory usage (GAP may allocate more) (only available if GAP uses GASMAN)

- **-K**, **--limitworkspace** \<mem\>

  set maximal workspace size (GAP never allocates more)

- **-s**

  \<mem\>     set the initially mapped virtual memory (only available if GAP uses GASMAN)

### Roots:

- **-l**, **--roots**

  \<paths\>   set or modify the GAP root paths Directories are separated using ';'. Putting ';' on the start/end of list appends directories to the end/start of existing list of root paths

- **-r**

  disable/enable user GAP root dir GAPInfo.UserGapRoot

### Loading:

- **-A**

  disable/enable autoloading of suggested GAP packages

- **-D**

  enable/disable debugging the loading of files

- **-M**

  disable/enable loading of compiled modules

### Error handling, REPL:

- **-T**, **--nobreakloop**

  disable/enable break loop and error traceback

- **--alwaystrace**

  always print error traceback (overrides behaviour of **-T**)

- **--quitonbreak**

  quit GAP with non-zero return value instead of entering break loop

- **--norepl**

  Disable the GAP read-evaluate-print loop (REPL)

- **--nointeract**

  Start GAP in non-interactive mode (disable REPL and break loop)

### Workspaces:

-

  (only available if GAP uses GASMAN):

- **-L**

  \<file\>    restore a saved workspace

- **-R**

  prevent restoring of workspace (ignoring **-L**)

### Profiling:

- **--prof**

  \<file\>    Run ProfileLineByLine(\<file\>) on GAP start

- **--memprof**

  \<file\>    Run ProfileLineByLine(\<file\>) on GAP start with recordMem := true

- **--cover**

  \<file\>    Run CoverageLineByLine(\<file\>) on GAP start

Internal developer tools

- **-N**

  do not use hidden implications

- **-O**

  disable/enable loading of obsolete files

- **--bare**

  Attempt to start GAP without even needed packages

-

  Short boolean options toggle the current value each time they are called. Default actions are indicated first.

## AUTHORS

The GAP Group \<http://www.gap-system.org\>

## COPYRIGHT

     Copyright (1988--2024) by its authors.

     GAP  is free software; you can redistribute it and/or modify it under the  terms  of  the  GNU  General  Public  License as published by the Free Software  Foundation;  either version 2 of the License, or (at your option) any  later  version.

## SEE ALSO

*[gac(1)](/gac/1.md)* *[update-gap-workspace(1)](/update-gap-workspace/1.md)*

You can read the complete manual in /usr/share/gap/doc or you can use the online help system. Type ?help inside GAP to access it. Type

?Reference: options!under UNIX

to access the full documentation of options.