gfortran must have been made with the same gcc.  In particular, Mac users must not use
"homebrew" gcc and MacPorts gfortran - use both gcc and gfortran from MacPorts.  See 
OSX ALL below.

Source file sioseis-*.bz2 was create using tar and bzip2.
Follow Unix conventions and place the source code in directory src and the executables in bin.

cd src
Use tar -xjf sioseis-*.bz2 or bunzip2 and tar -xf.
cd  sioseis-*
make all



"make options:"

  clean   - remove all objects and executables"
  all     - build everything"
  tar     - create a release source tar using VERSION"

  sioseis - build just sioseis"
  sio2sun - build just sio2sun"
  sio2hp  - build just sio2hp"
  lsd     - build just lsd"
  lsh     - build just lsd"
  dutil   - build just dutil"

makefile uses FC=gfortran and CC=gcc.
gfortran and gcc must be the same revision, as is the case with Linux.
Macs come with gcc in /usr/bin and do not have gfortran.  Type:
which gfortran
then set the path of both gcc and gfortran so the are the same.

Many compiler flags are commented out in an effort of finding what
compiles on "every" machine I could find.  The most common denominator.

As of 2010, tape I/O probably will not work on non Sun computers 
    (mtio.h and other issues)


OSX ALL:
Use MacPorts (macports.org) to get ImageMagick, gfortran, and gcc.
CFLAGS = -O2 and other CFLAGS may be turned on.
Xcode must be loaded - it's on a disk that came with the computer.
*****    gcc must be the same that was used to make gfortran.  *****
*****    Do NOT use Apple's supplied gcc with GNU compiled gfortran  *****
OSX 10.5:
X86_64 machines may have to use CFLAGS = -m32
OSX 10.6:
Snow Leopard needs  FFLAGS += -funderscoring
OSX 10.7 with macports gcc and fink gfortran:
FFLAGS += -funderscore -m32
CFLAGS += -m32
OSX 10.8 - DO NOT USE gcc48 prelease BETA (Nov. 12)
IGPP supported MacIntosh use Apple's gcc and GNU gfortran and do not
need the -m32 flags nor the -funderscore, but must change makefile to:
FC=/usr/local/gfortran/bin/gfortran
CC=/usr/local/gfortran/bin/gcc
Mac OSX 10.12.8 
FC=gfortran-mp-6
CC=gcc-mp-6
The  'mp' means MacPorts and '6' means version 6 of the GNU tools. 
This is a common convention at this point to ensure you don't accidentally 
invoke incompatible C & Fortran compilers. You can safely have multiple 
versions from multiple software repositories if you need to build other code. 
Mac OSX 10.13.4 (July 2018)
FC=gfortran-mp-4.9
CC=gcc-mp-4.9



Linux:
Older Redhat systems may have to use FC=f77 or FC=/usr/bin/f77
gcc  -m32 does not work with gfortran on gcc version 4.1.2 20080704 (Red Hat 4.1.2-46)
gcc   -O and -02 do not work under gcc version 4.1.2 20080704 (Red Hat 4.1.2-46)



CYGWIN:
makefile uses FC=gfortran and CC=gcc.
gfortran and gcc must be the same revision, as is the case with Linux.
e.g. confirm this by:
41>gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-pc-cygwin/4.5.3/lto-wrapper.exe
Target: i686-pc-cygwin
Configured with: /gnu/gcc/releases/respins/4.5.3-3/gcc4-4.5.3-3/src/gcc-4.5
42>gfortran -v
Using built-in specs.
COLLECT_GCC=gfortran
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-pc-cygwin/4.5.3/lto-wrapper.exe
Target: i686-pc-cygwin
Configured with: /gnu/gcc/releases/respins/4.5.3-3/gcc4-4.5.3-3/src/gcc-4.5.3/configure

If need be, use the FC and CC statements to get to the correct compilers.
e.g. 
FC=/usr/bin/gfortran
CC=/usr/bin/gcc


Suns:
FC=f77 
CC=cc
Remember to use gmake rather than Sun's make.
In makefile use  magsun.o rather than  magmacosx.o
Also in makefile, delete lines:
FFLAGS += -funroll-loops
FFLAGS += -fexpensive-optimizations
FFLAGS += -ffast-math     LD=lgfortran 
LDFLAGS:=-lgfortran


See http://sioseis.ucsd.edu