Installing Flex-2.5.4a

Estimated build time:           0.1 SBU
Estimated required disk space:  3.4 MB

Contents of Flex

The Flex package is used to generate programs which recognize patterns in text.

Installed programs: flex, flex++ (link to flex) and lex

Installed library: libfl.a

Flex Installation Dependencies

Flex depends on: Bash, Binutils, Bison, Coreutils, Diffutils, GCC, Gettext, Glibc, Grep, M4, Make, Sed.

Installation of Flex

Prepare Flex for compilation:

./configure --prefix=/usr

Compile the package:


This package has a test suite available which can perform a number of checks to ensure it built correctly. Should you choose to run it, the following command will do so:

make bigcheck

And install the package:

make install

There are some packages that expect to find the Lex library in /usr/lib. Create a symlink to account for this:

ln -s libfl.a /usr/lib/libl.a

A few programs don't know about flex yet and try to run its predecessor lex. To support those programs, create a shell script named lex that calls flex in Lex emulation mode:

cat > /usr/bin/lex << "EOF"
# Begin /usr/bin/lex

exec /usr/bin/flex -l "$@"

# End /usr/bin/lex
chmod 755 /usr/bin/lex