If building, developing or compiling C programs is new to you, you probably want to use your operating system's standard means of installing software to install flex. If you do not need the latest features of flex, you probably just want to use your operating system's standard means of installing software to obtain flex.
If you are not familiar with bootstrapping C code from a git
repository or if GNU autotools seems like a jumble of tenuous
incantationery to you, then make sure that you downloaded one of the
release tar archives of flex. You can verify this by checking the
filename of what you downloaded. If it is something like
flex-<version>.tar.<compressiontype>
then you have a release tar
archive. If you have a filename like flex.tar.gz
or flex.zip
, you
have a copy of the git repository and you didn't download the thing
you wanted to.
To build flex from a release archive:
$ ./configure <any configure options you need>
$ make
To see what options are available from the configure script:
$ ./configure --help
Optionally run the test suite:
$ make check
To install the flex you just built:
$ make install
Note that you may want to make use of the DESTDIR argument on the
make install
command line or that you may want to have used the
--prefix
argument with configure (or mostly equivalently the
prefix
argument on the make command line).
To build from the git repository:
First, make sure you have a copy of flex installed somewhere on your path so that configure can find it. You can usually do this with your operating system's standard means of installing software. Sometimes, you have to build from a recent release of flex, however. Using a version of flex built from the flex codebase is always acceptable if you have already bootstrapped doing so.
You will also need all the programs that flex needs in order to be built from scratch:
- compiler suite - flex is built with gcc
- bash, or a good Bourne-style shell
- m4 -
m4 -P
needs to work; GNU m4 and a few others are suitable - GNU bison; to generate parse.c from parse.y
- autoconf; for handling the build system
- automake; for Makefile generation
- make; for running the generated Makefiles
- gettext; for i18n support
- help2man; to generate the flex man page
- tar, gzip, lzip, etc.; for packaging of the source distribution
- GNU texinfo; to build and test the flex manual. Note that if you want to build the dvi/ps/pdf versions of the documentation you will need texi2dvi and related programs, along with a sufficiently powerful implementation of TeX to process them. See your operating system documentation for how to achieve this. The printable versions of the manual are not built unless specifically requested, but the targets are included by automake.
- GNU indent; for indenting the flex source the way we want it done
In cases where the versions of the above tools matter, the file configure.ac will specify the minimum required versions.
Then:
$ ./autogen.sh
After autogen.sh finishes successfully, building flex follows the same steps as building flex from a release archive.
Note that, in addition to make check
, make distcheck
builds a
release archive and builds and tests flex from inside a directory
containing only known distributed files.