Trouble with Linker Argument

[Rituparna]

Hi, I am new to Linux. I am trying to install the program "r8s" on my RHEL 5 through its makefile. This is the error I am receiving:

[Ritu@localhost src]$ make
gcc   -o r8s  -L/sw/lib   DrawTree.o TreeSim.o moment.o powell.o ConstrOpt.o MyUtilities.o WuLi.o DistrFuncs.o NRCvectorUtils.o distance.o penalty.o ObjFunc.o main.o relativeRates.o ReadNexusFile2.o  memory.o root3taxa.o TimeAlgorithms.o nextToken2.o storeNexusFile.o MinND.o TreeUtils.o structures.o blas.o tn.o TNwrapper.o continuousML.o ancestral.o -lg2c -lm  
/usr/bin/ld: cannot find -lg2c
collect2: ld returned 1 exit status
make: *** [r8s] Error 1

I know that libg2c.so.0 is located in /usr/lib. How do I tell the linker to look in that folder to access this library?

[Rubberman]

If you are running a 32-bit system, then this should work. If you are running a 64-bit system, then you need to see if a 64-bit version exists in /usr/lib64. If not and your are building on a 64-bit system, then you either need the 64-bit version of the library (libg2c.so or libg2c.a) or you need to build your application fully for 32-bit operation, in which case it will get the library from /usr/lib.

[Rituparna]

If you are running a 32-bit system, then this should work.

What should work?

I am running a 32-bit system.

Can I just edit the makefile itself?

Here is a portion of the original makefile:

 # Make file for r8s
# Updated April 2003 for Linux and Mac OS 10.2. No other builds currently supported
#
 
FC = g77  # Fortran compiler; standard on Linux, may have to go fetch this on OS X! (get it from Fink)
CC = gcc  # GNU C compiler
LIBS =  -lg2c -lm  # FORTRAN to C library, and standard C library 
LPATH = -L/sw/lib  # This is the directory where Mac's Fink stuck the g2c library 
#CFLAGS = -g -std=c99 -pedantic  # for debugging, etc. 
CFLAGS =  # usual case 
  

libg2c.so.0 and libm.so are both in /usr/lib. So I edited LPATH to equal -L/usr/lib.

But I am still getting the same error....

[Rubberman]

I noticed in my system that there is no libg2c.so, but there is .so.0 which is a link to .so.0.0.0. As root, go to /usr/lib and make a symbolic link from libg2c.so.0 to libg2c.so and try linking again.

[Rituparna]

Thanks so much for the help! That worked.