pb configure : flex lex???

[Anon]

under redhat 7.2
when running
#./configure --with-mysql --with-apxs
I've got this :
...
#checking for flex... lex
#checking for yywrap in -ll...no
#checking lex output file root... .
/configure: lex: command not found
#configure: error: cannot found output from lex; giving up
#[root@localhost php-4.0.6]
...

What can I do?

[Anon]

You mus install flex.rpm from Redhat 7.1 distribution! This program is a lexical analzer. Make script need this for lexical analyzing source code.

Nicholas

[Anon]

Thanks a lot
I 've done it and that 's ok
but now I 've got another pb after installing php and restart apache :

[root@localhost root]# /usr/local/apache/bin/apachectl restart
/usr/local/apache/bin/apachectl restart: configuration broken, ignoring restart
/usr/local/apache/bin/apachectl restart: (run 'apachectl configtest' for details)
[root@localhost root]# /usr/local/apache/bin/apachectl configtest
Syntax error on line 223 of after restart /usr/local/apache-1.3.22/conf/httpd.conf:
Cannot load /usr/local/apache-1.3.22/libexec/libphp4.so into server: /usr/local/apache-1.3.22/libexec/libphp4.so: undefined symbol: gdImageColorClosestAlpha
[root@localhost root]#

what can I do?
what this "gdImageColorClosestAlpha" who don't exist in this file?
thanks a lot