- Installation Overview
- Getting the Archive
- Unpacking
- Compilation
- Configure options
- Testing the installation
- Packages
- Finish Installation and Cleanup
- The Documentation
- If Things Go Wrong
- Known Problems of the Configure Process
- Optimisation and Compiler Options
- GAP for macOS
These are the installation instructions for the GAP source distribution on Unix (which covers Linux and macOS), and for the GAP binary distribution for Windows.
Alternative installation methods which aim to simplify the installation mostly by offering precompiled binaries are:
- GAP installer for Homebrew (package manager for macOS)
- Docker image for GAP and most of the packages
- the rsync-based binary distribution for Linux
Note, however, that these are updated independently and may not yet provide the latest GAP release. Further details are available on the GAP website here: https://www.gap-system.org/Download/alternatives.html.
The GAP source distribution is designed to be installed in a similar way on a wide range of operating systems and to allow for considerable customisation of the installation to meet specific system needs. As a result, it may differ from what you would expect under your particular operating system. In particular, it does not include an automatic installer program.
Installing the GAP distribution with all the packages and full data libraries
will require (except on Windows) both a C and a C++ compiler (gcc or clang
is recommended) to be installed on your system. Please also consult
section "Installing required dependencies" in the file README.md.
To get maximum benefit from GAP and from various packages, we recommend to install a number of other free software libraries (and their associated development tools) although they are not required for basic operation. See https://www.gap-system.org/Download/tools.html for more details.
The installation consists of five easy steps:
- Get the archive suitable for your system
- Unpack the archive in the directory where you wish to install GAP If you are reading this file as part of a GAP installation, you have probably already done this.
- Compile the kernel (unless a binary has been provided already)
- Test the installation
- Compile the packages that require it. (some of them will only work under Unix).
Installation will always install the new version of GAP. If you are worried about losing the old version, you can keep an existing installation of GAP in another directory, it will not be overwritten. Make sure, however, to adjust any links or scripts so that you run the latest version.
Section "The Documentation" below contains information about the manual, where to find and how to print it. Section "If Things Go Wrong" below lists common problems with the installation.
You can get archives for the GAP distribution from the GAP website at https://www.gap-system.org/Releases/. If you use Unix (including macOS), you need to download the GAP source distribution, that is, a file named
gap-4.X.Y.tar.bz2
for GAP 4.X.Y. Alternatively, you can also use the .tar.gz or .zip
archives.
If you use Windows, then download the .exe installer which contains binaries
for GAP and some packages and provides the standard installation procedure.
The exact method of unpacking will vary dependently on the operating system and the type of archive used.
Under Unix style operating systems (such as Linux and macOS), unpack the
archive gap-4.X.Y.tar.bz2 in whatever place you want GAP to reside.
It will expand into a directory named gap-4.X.Y.
(If you unpack the archive as root user under Unix, make sure that you
issue the command umask 022 before, to ensure that users will have
permissions to read the files.)
If you are using the .exe installer (which we strongly recommend),
simply download and run it. It will offer a standard installation
procedure, during which you will be able to select an installation path.
Note that the path to the GAP directory must not contain spaces.
For example, you may install it in a directory named like C:\gap-4.X.Y
(default), D:\gap or C:\Math\GAP\my-gap-4.X.Y, but you must not install
it in a directory named like C:\Users\alice\My Documents\gap-4.X.Y or
C:\Program files\gap-4.X.Y etc.
For the Windows version the .exe installer will already have put
binaries in place and nothing else needs to be done.
Under Unix you will have to compile such a binary yourself, as described in this section. This also covers macOS, but please first review section "GAP for macOS" below for additional information about compilation specific to macOS.
In order to compile GAP, you need at least these:
- a C compiler, e.g. GCC or Clang
- a C++ compiler
- GNU Make
In addition, we recommend that you install at least the following optional dependencies (if you do not, GAP will either build its own copies of these, slowing down the compilation process, or omit certain features):
- Development headers for GMP, the GNU Multiple Precision Arithmetic Library
- Development headers for zlib
- Development headers for GNU Readline
On Ubuntu or Debian, you can install these with the following command:
sudo apt-get install build-essential autoconf libtool libgmp-dev libreadline-dev zlib1g-dev
On macOS, please follow the instructions in section "GAP for macOS" below.
On other operating systems, you will need to figure out equivalent commands to install the required dependencies.
Note that several of the packages bundled with GAP have additional prerequisites. Here is an incomplete list of GAP packages and their requirements (excluding GMP, which many packages require):
- 4ti2Interface
- Debian/Ubuntu: 4ti2
- Homebrew: (not currently available)
- alnuth
- Debian/Ubuntu: pari-gp
- Homebrew: pari
- browse
- Debian/Ubuntu: libncurses-dev
- Homebrew: ncurses
- CddInterface
- Debian/Ubuntu: libcdd-dev
- Homebrew: cddlib
- curlInterface
- Debian/Ubuntu: libcurl4-openssl-dev
- Homebrew: curl
- float
- Debian/Ubuntu: libfplll-dev libmpc-dev libmpfi-dev libmpfr-dev
- Homebrew: fplll libmpc mpfi mpfr
- singular
- Debian/Ubuntu: singular
- Homebrew: singular
- ZeroMQInterface
- Debian/Ubuntu: libzmq3-dev
- Homebrew: zmq
Change to the directory gap-4.X.Y (which you just created by unpacking).
To get started quickly you may simply build GAP with default settings
by issuing the two commands
./configure
make
(note that on BSD systems you have to call gmake instead of make).
Both will produce a lot of text output. You should end up with an executable
called gap which you can use to start GAP. In addition, there is a shell
script bin/gap.sh which you can copy to a directory that is listed in your
search path. (This shell script starts the gap executable and also passes
an argument to it that indicates where the GAP library is).
macOS users please note that this script must be started from within the Terminal Application. It is not possible to start GAP by clicking this script.
If you get strange error messages from these commands, make sure that you extracted the archive on the same machine on which you compile. See also the section "Known Problems of the Configure Process" below.
Note that starting with GAP 4.12, there is experimental support for installing
GAP via make install. By default this attempts to install GAP into the
/usr prefix, but this can be adjusted via the --prefix option for
configure. This feature is still quite new and has not received extensive
testing yet, and we mainly recommend it for use by people who wish to package
GAP for a Linux distribution or similar. Note also that make install at this
time only installs GAP itself; GAP packages still must be installed manually
(which in many cases just means copying them into a suitable directory, e.g.
<GAPPREFIX>/share/gap/pkg/ -- we are still working on a good solution for
packages that require compilation).
There are several options to the build process which you can specify at the configure step. The following paragraphs describe these options; a brief description of each is also available via
./configure --help
GAP 4 uses the external library GMP (see https://gmplib.org) for large integer arithmetic, replacing the built-in code used in previous versions and achieving a significant speed-up in related computations. There is a version of GMP included with the GAP archive you downloaded and this will be used if GAP does not find a version of GMP already installed on your system. You can configure which GMP GAP uses as follows:
./configure --with-gmp=builtin|PREFIX
If this option is not given, GAP will try to find a suitable version of GMP can be found using the specified CPPFLAGS, CFLAGS and LDFLAGS. If not, it will fallback to compiling its own version of GMP.
You can force GAP to build its own copy of GMP by passing --with-gmp=builtin.
Finally, you pass a prefix path where GAP should search for a copy of GMP;
i.e., --with-gmp=PREFIX instructs GAP to search for the header file gmp.h
in PREFIX/includes, and the library itself in PREFIX/lib.
For historical reasons, you may also pass --with-gmp=system, which is
simply ignored by GAP (i.e., the default behavior described above is used).
GAP optionally also uses the external library GNU Readline (see https://www.gnu.org/software/readline) for better command line editing. GAP will use this library by default if it is available on your system. You can configure Readline use as follows:
./configure --with-readline=yes|no|"path"
If the argument you supply is yes, then GAP will look in standard locations
for a Readline installed on your system. Or you can specify a path to a
Readline installation. If the supplied argument is no then readline support
will not be used.
Note that --with-readline is equivalent to --with-readline=yes and
--without-readline is equivalent to --with-readline=no.
GAP will attempt to build in 32-bit mode on 32-bit machines and in 64-bit mode on 64-bit machines. On a 64-bit machine, you can tell GAP to build in 32-bit instead, if you know what you are doing. Note that we recommend against doing this for regular use, as these days the 64 bit version is much better tested and generally faster.
If you wish to force GAP in 32-bit mode, you can do so by invoking
./configure ABI=32
make
The value of the argument determines the build mode GAP will attempt to use. Note that building in 64-bit mode on a 32-bit architecture is not supported.
It is possible (on a 64-bit machine) to have builds in both 32- and 64-bit
modes using "out of tree builds". For details, please refer to the file
README.buildsys.md.
You are now at a point where you can start GAP for the first time. Unix users (including those on macOS) should type
./gap
Windows users should start GAP with the batch file
C:\gap-4.X.Y\bin\gap.bat
GAP should start up with its banner and after a little while give you a command prompt
gap>
Try a few commands to see if the compilation succeeded.
gap> 2 * 3 + 4;
10
gap> Factorial( 30 );
265252859812191058636308480000000
gap> m11 := Group((1,2,3,4,5,6,7,8,9,10,11),(3,7,11,8)(4,10,5,6));;
gap> Size( m11 );
7920
gap> Length( ConjugacyClasses( m11 ) );
10
gap> Factors( 10^42 + 1 );
[ 29, 101, 281, 9901, 226549, 121499449, 4458192223320340849 ]
If you get the error message hmm, I cannot find lib/init.g you are likely
to have installed only the binary (or used the wrong path on Windows).
If GAP starts but you get error messages for the commands you issued, the
files in the lib directory are likely to be corrupt or incomplete. Make
sure that you used the proper archive and that extraction proceeded without
errors.
Especially try the command line editing and history facilities, because
they are probably the most machine dependent feature of GAP. Enter a few
commands and then make sure that Ctrl-P redisplays the last command, that
Ctrl-E moves the cursor to the end of the line, that Ctrl-B moves the
cursor back one character, and that Ctrl-D deletes single characters. So,
after entering the above commands, typing
Ctrl-P Ctrl-E Ctrl-B Ctrl-B Ctrl-B Ctrl-B Ctrl-D 2 Return
should give the following lines:
gap> Factors( 10^42 + 2 );
[ 2, 3, 433, 953, 128400049, 3145594690908701990242740067 ]
If you want to run a quick test of your GAP installation (though this is not required), you can read in a test script that exercises some GAP's capabilities. To run this test, we recommend to use a computer with at least 1 GB of memory; on an up-to-date desktop computer, it should complete in about a minute. You will get a large number of lines with output about the progress of the tests, for example:
gap> Read( Filename( DirectoriesLibrary( "tst" ), "testinstall.g" ) );
Architecture: SOMETHING-SOMETHING-gcc-default64
testing: ..../gap-4.X.Y/tst/testinstall/alghom.tst
84 ms (55 ms GC) and 2.90MB allocated for alghom.tst
testing: ..../gap-4.X.Y/tst/testinstall/algmat.tst
839 ms (114 ms GC) and 219MB allocated for algmat.tst
[ further lines deleted ]
testing: ..../gap-4.X.Y/tst/testinstall/zmodnze.tst
127 ms (119 ms GC) and 1.29MB allocated for zmodnze.tst
-----------------------------------
total 62829 ms (24136 ms GC) and 8.61GB allocated
0 failures in 252 files
#I No errors detected while testing
GAP will exit after this test with the corresponding exit code (this is
useful for automated testing). If you want to run a more advanced check
(this is not required and may take up to an hour), you can start a new
GAP session and read teststandard.g which is an extended test script
performing all tests from the tst directory.
gap> Read( Filename( DirectoriesLibrary( "tst" ), "teststandard.g" ) );
It takes significantly longer to complete than testinstall.g,
but otherwise produces output similar to the testinstall.g test.
Windows users should note that the Command Prompt user interface provided
by Microsoft might not offer history scrolling or cut and paste with the
mouse. To get a better environment, use the script gap.bat to start GAP
instead of gapcmd.bat.
The GAP distribution already contains all the GAP packages which we
redistribute in the gap-4.X.Y/pkg directory, and for packages that consist
only of GAP code no further installation is necessary.
Some packages however contain external binaries that will require separate compilation. (If you use Windows you may not be able to use external binaries anyhow, except for those packages whose binaries for Windows are included in their distribution, so you may skip the rest of this section.) You can skip this compilation now and do it later -- GAP will work fine, but the capabilities of the affected packages won't be available.
In general, each package contains a README file that contains information
about the package and the necessary installation. Typically, for a package
that requires compilation, the installation steps consist of changing to
the packages directory and issuing the commands ./configure && make in
the packages directory. This has to be done separately for every package,
and their README files should tell exactly which commands to use.
To help with this tedious process, we ship a shell script called
bin/BuildPackages.sh that will compile most of the packages that require
compilation on Unix systems (including Linux and macOS) with sufficiently
many libraries, headers and tools available. To use it, change to the
gap-4.X.Y/pkg directory and execute the script like this:
../bin/BuildPackages.sh
If you have problems with package installations please contact the package authors as listed in the packages README file. Many GAP packages have their own development repositories and issue trackers, details of which could be found at https://gap-packages.github.io/.
Congratulations, your installation is finished.
Once the installation is complete, we would like to ask you to send us a short note to support@gap-system.org, telling us about the installation. (This is just a courtesy; we like to know how many people are using GAP and get feedback regarding difficulties (hopefully none) that users may have had with installation.)
We also suggest that you subscribe to our GAP Forum mailing list; see the GAP web pages for details. Whenever there is a bug fix or new release of GAP this is where it is announced. The GAP Forum also deals with user questions of a general nature; bug reports and other problems you have while installing and/or using GAP should be sent to support@gap-system.org.
If you are new to GAP, you might want to read through the following two sections for information about the documentation.
The GAP documentation is distributed in various "books". The standard
distribution contains two of them. GAP packages (see Chapter "GAP Packages"
of the GAP Reference manual and, in particular, the Section "Loading a GAP
Package") provide their own documentation in their own doc directories.
All documentation will be available automatically within every GAP session (see Section "Help" of the GAP Tutorial and Chapter "The Help System" in the GAP Reference manual).
There also is (if installed) an HTML version of some books that can be viewed with an HTML browser, see Section "Changing the Help Viewer" of the GAP Reference manual.
The manual is also available in pdf format. In the full distribution these
files are included in the directory gap-4.X.Y/doc in the subdirectories
tut (a beginner's tutorial), ref (the reference manual), and hpc (HPC-GAP
reference manual).
If you want to use these manual files with the help system from your GAP session you may check (or make sure) that your system provides some additional software like xpdf or acroread.
To complete beginners, we suggest you read (parts of) the tutorial first for an introduction to GAP 4. Then start to use the system with extensive use of the help system (see Section "Help" of the GAP Tutorial and Chapter "The Help System" in the GAP Reference manual).
As some of the manuals are quite large, you should not immediately print them. If you start using GAP it can be helpful to print the tutorial (and probably the first chapters of the reference manual). There is no compelling reason to print the whole of the reference manual, better use the help system which provides useful search features.
This section lists a few common problems when installing or running GAP and their remedies. Also see the FAQ list on the GAP web pages at https://www.gap-system.org/Faq/faq.html.
This means that GAP cannot find its library. That can happen if you are using
the shell script gap.sh respectively the batch file gap.bat but have moved
the GAP home directory since you compiled GAP. To fix this, you can edit the
shell script/batch file to give the correct library path. You must start the
binary with the command line option
-l <path>
where <path> is the path to the GAP home directory (see Section "Command
Line Options" of the GAP Reference manual).
You might have a .gaprc file in your home directory that was used by
GAP 4.4 but is not compatible with later releases. See section "The gap.ini
and gaprc files" in Section "Running GAP" of the GAP Reference manual.
Your job required more memory than is permitted by default (this is a
safety feature to avoid single jobs wrecking a multi-user system.) You can
type return; to continue, if the error message happens repeatedly it might
be better to start the job anew and use the command line option -o to set a
higher memory limit.
Your calculation exceeded the available memory. Most likely you asked GAP
to do something which required more memory than you have (as listing all
elements of S_15 for example). You can use the command line option -g (see
Section "Command Line Options" of the GAP Reference manual) to display how
much memory GAP uses. If this is below what your machine has available
extending the workspace is impossible. Start GAP with more memory using the
-o option.
In a 32-bit mode GAP is unable to use over 4 GB of memory. In fact, since some address space is needed for system purposes, it is likely that GAP sessions will be limited to 3 GB or even less. There are other factors which can reduce this limit even further.
We therefore recommend to always build and use GAP in 64-bit mode.
Call make clean and restart the configure / make process completely from
scratch. (It is possible that the operating system and/or compiler got
upgraded in the meantime and so the existing .o files cannot be used any
longer.
GAP is not able to execute a certain operation with the given arguments. Besides the possibility of bugs in the library this means two things: Either GAP truly is incapable of coping with this task (the objects might be too complicated for the existing algorithms or there might be no algorithm that can cope with the input). Another possibility is that GAP does not know that the objects have certain nice properties (like being finite) which are required for the available algorithms. See section "ApplicableMethod" and "KnownPropertiesOfObject" of the GAP Reference manual.
This is a problem if you are running a keyboard driver for some non-english
languages. These drivers catch the ^ character to produce the French circumflex
accent and do not pass it properly to GAP. For macOS users, as a workaround
please refer to the section "GAP for macOS" below for information on
how to install readline and section 5 on how to recompile GAP, for windows no
fix is known. (One can type POW(a,b) for a^b.)
You might want to try different shells, using both of the two .bat
files in the bin directory: gap.bat and gapcmd.bat. Also,
https://www.gap-system.org/Faq/faq.html#4 might give a remedy.
GAP cannot be started in the Windows Command Prompt shell (via gapcmd.bat)
in the remote desktop. To start GAP in the remote desktop, use the script
gap.bat which should work in such setting.
GAP comes with a version of this dynamic library. If you have another version installed (use "Find"), delete the older one (and probably copy the newer one in both places).
If all these remedies fail or you encountered a bug please send a mail to support@gap-system.org. Please give:
-
a (short, if possible) self-contained excerpt of a GAP session containing both input and output that illustrates your problem (including comments of why you think it is a bug); and
-
state the type of machine, the operating system, which compiler you used (if any), and the version of GAP you are using (the line from the GAP banner starting with
GAP, Version 4.X.Y...when GAP starts up, supplies the information required).
The configure script respects compiler settings given in environment
variables. However such settings may conflict with the automatic
configuration process. If configure produces strange error messages about
not being able to run the compiler, check whether environment variables
that might affect the compilation (in particular CC, CXX, CPP, LD,
CFLAGS, CXXFLAGS, CPPFLAGS and LDFLAGS) are set and reset them using
unsetenv.
Because of the large variety of different versions of Unix and different
compilers it is possible that the configure process will not chose best
possible optimisation level, but you might need to tell make about it.
If you want to compile GAP with further compiler options (for example
specific processor optimisations) you will have to assign them to the
variables CFLAGS, CXXFLAGS, CPPFLAGS and LDFLAGS, then re-run
configure and make.
If there are several compiler options or if they contain spaces you might have to enclose them by quotes depending on the shell you are using.
The configure process also introduces some default compiler options. You can
eliminate these by assigning the replacement options to the variable CFLAGS.
The recommended C/C++ compiler for GAP is the GNU C compiler gcc version 4.8 or later. The Clang compiler version 3.0 and later also should work fine. If you use another compiler, please let us know your experience with using it to compile GAP.
If you do wish to use GAP with a specific compiler, you can set the environment
variables CC resp. CXX to the name of your preferred C resp. C++ compiler
and then rerun configure and make.
As an example, here is how one can configure GAP to compile with Clang 5 (assuming it is installed on your system), with custom compiler flags and debug mode enabled:
./configure CC=clang-5.0 CXX=clang++-5.0 CFLAGS="-g -Og" CXXFLAGS="-g -Og" --enable-debug
Currently we provide no precompiled binary distribution for macOS. However, since macOS is an operating system in the Unix family, you can follow the Unix installation guidelines to compile GAP; then you will be able to use all features of GAP as well as all packages. However for installation you might need a basic knowledge of Unix.
The following are a couple of notes and remarks about this:
To compile and run GAP you will have to open the Terminal application and
type the necessary Unix commands into its window. The Terminal application
can be found in the Utilities folder in the Applications folder.
Next, you will need a compiler and build tools like make. These tools are
included in the "Xcode" application which is not installed by default on a
new Mac. On all recent versions of macOS, you can install the required tools
by entering the following command into a terminal prompt (note that it will
show a graphical prompt asking for confirmation, and may also require you
to enter an administrator password).
xcode-select --install
If you are using a macOS package manager, we recommend installing a few for faster compilation and a better user experience:
- using Homebrew:
brew install gmp readline - using Fink:
fink install gmp readline7 - using MacPorts:
port install gmp readline
Now simply follow the Unix installation instructions to compile and start GAP and then it will run in this Terminal window.