答案1
事实上并非如此。bison仅仅是建议包裹。
$ apt-cache show flex
Package: flex
Priority: optional
Section: devel
Installed-Size: 468
Maintainer: Ubuntu Developers <[email protected]>
Original-Maintainer: Manoj Srivastava <[email protected]>
Architecture: i386
Version: 2.5.35-10.1ubuntu2
Depends: libc6 (>= 2.11), m4, libfl-dev (= 2.5.35-10.1ubuntu2), dpkg (>= 1.15.4) | install-info
Pre-Depends: debconf | debconf-2.0
Recommends: gcc | c-compiler
Suggests: bison, build-essential
Filename: pool/main/f/flex/flex_2.5.35-10.1ubuntu2_i386.deb
Size: 198826
MD5sum: 27cb81027d75db58240873ec3f8fd3ed
SHA1: 253c08edd934d7e3a85beca7c527c7598544dada
SHA256: 870bc45e20265ba718ee9872a04d2d95e0af414eeb3129a16c53f0229965df5f
Description-en: A fast lexical analyzer generator.
Flex is a tool for generating scanners: programs which recognized lexical
patterns in text. It reads the given input files for a description of a
scanner to generate. The description is in the form of pairs of regular
expressions and C code, called rules. Flex generates as output a C source
file, lex.yy.c, which defines a routine yylex(). This file is compiled
and linked with the -lfl library to produce an executable. When the
executable is run, it analyzes its input for occurrences of the regular
expressions. Whenever it finds one, it executes the corresponding C code.
Description-md5: 2e3fd254c37c87fd9abf35386a54cb30
Multi-Arch: foreign
Homepage: http://flex.sf.net/
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Origin: Ubuntu
Supported: 5y
您可以简单地flex使用进行安装sudo apt-get install flex。