1. #!/bin/bash -> #! /bin/sh
the bash shell is not found on all unixes; on my OpenBSD box it's in
/usr/local/bin/bash. /bin/sh is found everywhere and is the de-facto standard
it works just as well with this script as GNU bash. The space after #!
makes the script also work on some very old BSD systems.
#i updated this one

2. GNU head (from textutils) has additional features that are not defined
in POSIX, so most ordinary unix head utilities don't understand the -c
option. seq (from GNU sh-utils) is mostly found on Linux. i've included
installation instructions for the open-source BSD's.

3. md5sum is known on BSD as md5
#this is not used anymore

unfortunately, there is no easy way to test for the existence of the different
programs. I tried

head_prog=`whereis ghead || whereis head` # ghead = GNU head

but whereis isn't standardized either. which also doesn't work, since it
includes errors (foo: Command not found) in stdout, and i was too lazy
to find a work-around. the way configure scripts search for
programs is excessive and would make this script much longer. So people
will have to set the {head,seq,md4}_prog variables by hand if something
doesn't work :(

--
chris / memeater / xwrits / memwrits

--- ree.orig	Sun Dec 30 07:44:25 2001
+++ ree	Sun Dec 30 07:49:22 2001
@@ -1,9 +1,24 @@
-#!/bin/bash
+#! /bin/sh
 
 #rom extension extractor (ported to shell from the pascal version of 1997)
 #extracts system, scsi, video bios
 #gurkan@linuks.mine.nu, www.linuks.mine.nu
 
+# You need the GNU sh-utils and textutils for this to work.
+# They come with most (all?) Linux distros; BSD users will have to install
+# from the ports/pkgsrc system.
+#
+# FreeBSD, OpenBSD: /usr/ports/misc/sh-utils , /usr/ports/textproc/textutils
+# NetBSD: /usr/pkgsrc/sysutils/sh-utils , /usr/pkgsrc/textproc/textutils
+#
+# Also, you may need to run this script as root, depending on /dev/mem's
+# file permissions.
+
+# choose the utilities which work best for you
+md5_prog=md5sum # or: md5 (BSD)
+seq_prog=seq # or: gseq (BSD, others)
+head_prog=head # or: ghead (BSD, others)
+
 #scan from c0000 - f0000 in 512 byte blocks
 #U4{l}{code}
 #l*512=length of the code including headers
@@ -12,9 +27,9 @@
 start=`echo $start/512|bc`
 last=`echo "ibase=16;F0000"|bc`
 last=`echo $last/512|bc`
-for a in `seq $start 1 $last`; do
-    b=`dd if=/dev/mem skip=$a count=1 2>/dev/null |head -c2`
-    md5=`echo $b |md5sum`
+for a in `$seq_prog $start 1 $last`; do
+    b=`dd if=/dev/mem skip=$a count=1 2>/dev/null |$head_prog -c2`
+    md5=`echo $b |$md5_prog`
     if [ "$md5" = "7c77a5106b9621d1e49f8f9542d7ef80" ]; then
 	file=`echo "obase=16; $a*512"|bc |tr [A-Z] [a-z]`
 	size=`dd if=/dev/mem skip=$a count=1 2>/dev/null |tail -c+3`