安装php-4.3.2 不成功

onion_gz

# ./configure --with-mysql=/usr/local/mysql --with-apxs=/usr/local/apache/bin/apxs
creating cache ./config.cache
checking host system type... i686-pc-linux-gnu
Updated main/php_version.h
checking for gcc... gcc
checking whether the C compiler (gcc  ) works... yes
checking whether the C compiler (gcc  ) is a cross-compiler... no
checking whether we are using GNU C... yes
checking whether gcc accepts -g... yes
checking whether gcc and cc understand -c and -o together... yes
checking how to run the C preprocessor... gcc -E
checking for AIX... no
checking if compiler supports -R... no
checking if compiler supports -Wl,-rpath,... yes
checking for ranlib... ranlib
checking whether ln -s works... yes
checking for gawk... gawk
checking for bison... no
checking for byacc... no
configure: warning: You will need bison if you want to regenerate the PHP parsers.
checking for flex... lex
checking for yywrap in -ll... no
checking lex output file root... ./configure: line 2356: lex: command not found
configure: error: cannot find output from lex; giving up

是不是要安装flex? 我找到了flex，但安装也报错，郁闷啊。。。。
到底应该怎么办？ 3q 各位了

sd44

安装flex