What is flex/lex?

Fermat

I'm trying to install PHP 4.3.1 on linux. After I enter

./configure

I get the following error messages.

...
...
checking for flex... lex
checking for yywrap in -ll... no
checking lex output file root... ./configure: line 2482: lex: command not found
configure: error: cannot find output from lex; giving up

Wht is flex or lex? How do I find it? I did a search for flex on my linux partition but found nothing. Is it something I need to include in my PATH?

daveo

'flex' is the GNU update to 'lex'. In most general cases, either will do. 'lex' often refers to the original AT&T release.

'flex' (as well as lex) is a tool used to build "lexical analyzers" or "token parsers". Unless either of these terms really gets you excited, you really don't need to know more about them. (I happen to like building interpreters so f/lex, along with yacc/bison, are fun toys to play with!)

What you do need to know is that you can download them, install them and be on your way.

I will assume (based on the fact that you said "./configure") that you are operating on a Linux system. With this in mind, you should be able to find a nice RPM or even source for flex around and install it.

I will stop here to see if you need any further help on this...

--daveo

Fermat

Thanks for the info.
I found flex-2.5.4a.tar.gz, and installed that. Unfortunately the installation needed yacc, so I had to go find bison.
Installed bison (bison-1.875.tar.gz) ok, now flex installed ok too.
Finally got php installed and configured with apache 1.3.27 and mysql 4.1.0. Everything's up and running on my linux/mandrake - as you guessed.😃