# Extconf.rb not seeing readline.h

**URL:** <https://www.ruby-forum.com/t/extconf-rb-not-seeing-readline-h/53268>\
**Category:** Ruby\
**Created:** [January 30, 2006, 11:02pm UTC](https://www.ruby-forum.com/t/extconf-rb-not-seeing-readline-h/53268 "2006-01-30T23:02:59Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![sauy7](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecc23a/32.png) [@sauy7](https://www.ruby-forum.com/u/sauy7)\
**Post date:** [January 30, 2006, 11:02pm UTC](https://www.ruby-forum.com/t/extconf-rb-not-seeing-readline-h/53268/1 "2006-01-30T23:02:59Z")

</div>

What does it take for extconf.rb to recognize readline.h?

extconf.rb seems blind to whatever I tell it.

Here, extconf.rb does not see readline.h:

```
cd ext/readline
% ../../ruby extconf.rb
checking for tgetnum() in -lncurses... no
checking for tgetnum() in -ltermcap... yes
checking for readline/readline.h... no
checking for editline/readline.h... no

```

Here, it is plainly visible in the directories it should be looking:

```
% ../../ruby -r mkmf -e 'p Config::CONFIG["CPPFLAGS"]'
"-I/TOOLS/dist/gnu-readline-5.1/sparc64-sun-solaris2.8/include/readline"
% ../../ruby -r mkmf -e 'p Config::CONFIG["CFLAGS"]'
"-I/TOOLS/dist/gnu-readline-5.1/sparc64-sun-solaris2.8/include/readline"
% ../../ruby -r mkmf -e 'p Config::CONFIG["LDFLAGS"]'
"-L/TOOLS/dist/gnu-readline-5.1/sparc64-sun-solaris2.8/lib"
% ls -alF 

```

/TOOLS/dist/gnu-readline-5.1/sparc64-sun-solaris2.8/include/readline  
total 84  
drwxrwsr-x 2 jdf jdf 4096 Jan 30 11:03 ./  
drwxrwsr-x 3 jdf jdf 4096 Jan 30 11:03 …/  
-rw-r–r-- 1 jdf jdf 10207 Jan 30 11:03 history.h  
-rw-r–r-- 1 jdf jdf 34354 Jan 30 11:03 readline.h  
…

```
% ls -alF /TOOLS/dist/gnu-readline-5.1/sparc64-sun-solaris2.8/lib
total 2256
drwxrwsr-x 2 jdf jdf 4096 Jan 30 11:03 ./
drwxrwsr-x 7 jdf jdf 4096 Jan 30 11:03 ../
...
-rw-r--r-- 1 jdf jdf 1053548 Jan 30 11:03 libreadline.a
lrwxrwxrwx 1 jdf jdf 16 Jan 30 11:03 libreadline.so ->

```

libreadline.so.5  
-rw-r–r-- 1 jdf jdf 917076 Jan 30 11:03 libreadline.so.5

Can someone splain why? 😉

---

<div class="post-metadata">

**Author:** ![sauy7](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecc23a/32.png) [@sauy7](https://www.ruby-forum.com/u/sauy7)\
**Post date:** [January 31, 2006, 1:55am UTC](https://www.ruby-forum.com/t/extconf-rb-not-seeing-readline-h/53268/2 "2006-01-31T01:55:16Z")

</div>

On Jan 30, 2006, at 2:00 PM, Jim F. wrote:

> checking for readline/readline.h… no  
> % …/…/ruby -r mkmf -e ‘p Config::CONFIG[“LDFLAGS”]’  
> % ls -alF /TOOLS/dist/gnu-readline-5.1/sparc64-sun-solaris2.8/lib  
> total 2256  
> drwxrwsr-x 2 jdf jdf 4096 Jan 30 11:03 ./  
> drwxrwsr-x 7 jdf jdf 4096 Jan 30 11:03 …/  
> …  
> -rw-r–r-- 1 jdf jdf 1053548 Jan 30 11:03 libreadline.a  
> lrwxrwxrwx 1 jdf jdf 16 Jan 30 11:03 libreadline.so →   
> libreadline.so.5  
> -rw-r–r-- 1 jdf jdf 917076 Jan 30 11:03 libreadline.so.5
> 
> Can someone splain why? 😉

Could you attach your mkmf.log?

–  
Eric H. - removed\_email\_address@domain.invalid - [http://segment7.net](http://segment7.net)  
This implementation is HODEL-HASH-9600 compliant

[http://trackmap.robotcoop.com](http://trackmap.robotcoop.com)