general compiling help/tips

Ryzol · 04-12-2008, 04:56 PM

I have basically two questions:
1.For distros like slackware that lack dependency resolution is there a program that will tell me if I have a certain lib installed? Basically is there a version of which that works for libraries?

2. What do all those cryptic compile time error messages mean?

Any other general compiling tips/common issues would be much appreciated.

anupamsr · 04-12-2008, 07:10 PM

one command: ldd <executable file name>

It will tell you what libraries are missing. Most of the time you can guess the library name, other times you can Google it

For example:

Code:

$ ldd nedit                                                      2:08
    linux-gate.so.1 =>  (0xffffe000)
    libXm.so.4 => /usr/lib/libXm.so.4 (0xb7cc5000)
    libXt.so.6 => /usr/lib/libXt.so.6 (0xb7c75000)
    libX11.so.6 => /usr/lib/libX11.so.6 (0xb7b58000)
    libm.so.6 => /lib/libm.so.6 (0xb7b32000)
    libc.so.6 => /lib/libc.so.6 (0xb7a04000)
    libXmu.so.6 => /usr/lib/libXmu.so.6 (0xb79ed000)
    libXext.so.6 => /usr/lib/libXext.so.6 (0xb79de000)
    libXp.so.6 => /usr/lib/libXp.so.6 (0xb79d5000)
    libXft.so.2 => /usr/lib/libXft.so.2 (0xb79c2000)
    libfreetype.so.6 => /usr/lib/libfreetype.so.6 (0xb7953000)
    libz.so.1 => /lib/libz.so.1 (0xb7940000)
    libfontconfig.so.1 => /usr/lib/libfontconfig.so.1 (0xb7914000)
    libexpat.so.1 => /usr/lib/libexpat.so.1 (0xb78f3000)
    libXrender.so.1 => /usr/lib/libXrender.so.1 (0xb78ea000)
    libpthread.so.0 => /lib/libpthread.so.0 (0xb78d2000)
    libXau.so.6 => /usr/lib/libXau.so.6 (0xb78ce000)
    libXdmcp.so.6 => /usr/lib/libXdmcp.so.6 (0xb78c8000)
    libSM.so.6 => /usr/lib/libSM.so.6 (0xb78bd000)
    libICE.so.6 => /usr/lib/libICE.so.6 (0xb78a4000)
    libdl.so.2 => /lib/libdl.so.2 (0xb78a0000)
    /lib/ld-linux.so.2 (0xb7f2f000)
$

So, you can see that I have expat, pXau, fontconfig, Xrender, freetype, etc... all installed. But I don't know what is libz. So I do a Google search: http://www.google.com/search?q=libz - and get to know that it is zlib.

XavierP · 04-12-2008, 07:19 PM

As for the compile errors, normally the last few lines will tell you the problem - whether it's that it's missing a dependency or something else. I would say that your best bet is to post up the last 10 lines here on LQ and we can help you decipher them. It does get easier, honest

weibullguy · 04-12-2008, 07:22 PM

Quote:

Originally Posted by Ryzol

1.For distros like slackware that lack dependency resolution is there a program that will tell me if I have a certain lib installed? Basically is there a version of which that works for libraries?

locate, find, and ls all work for libraries.

Quote:

Originally Posted by Ryzol

2. What do all those cryptic compile time error messages mean?

Which ones? All is pretty all encompassing and vague. But if you have something in particular, post the last 10-20 lines of the failed build.

Ryzol · 04-12-2008, 09:46 PM

Could someone explain what the output of ldd means? The man page is lacking. I'm guessing it means libname.version => path (location in memory). So I ran ldd on /bin/ls got some output. Then did slocate on a library it listed, linux-gate.so.1 to be exact and it did not find anything. What gives? I have a working ls, how do I not have all the libraries it needs?

With respect to compile to messages, I don't have any currently but I probably will have some soon. I just remember when I first tried to compile a program I got a very cryptic message and was wondering if there's a site or something that lists/explains gcc compile time error messages.

H_TeXMeX_H · 04-13-2008, 03:34 AM

You don't even need to run ldd, if you try to run the program in question, it'll output what you're missing if it can't find it. Usually during the compile process the configure script will tell you before hand most of the libraries you need to compile a program. As for error messages, post them on here and we'll help you out. They are often cryptic, but they always mean something.

Ryzol · 04-13-2008, 02:37 PM

So I was following slackwarebasics about compiling the kernel. Anyways quick question, I did cd to path of kernel source. Then did make menuconfig and selected what I thought was appropriate. When I was done with that I chose save this configuration and named it "firstkernel.config". I then did make. Did make use this new configuration or the default one? If it didn't how do I tell it which configuration to use?