Squashed FATSTAT.LUA code further in case a FAT32 table parser is ever added.

Author: Lethja

demo/xtra/FATSTAT.LUA

@@ -1,9 +1,8 @@
 #!/usr/bin/env lua
 
 H=[[This script shows what blocks are allocated to what files on a FAT12/16 formatted floppy disk image (.IMA).
-The -z option will zero out unallocated clusters. Always backup the IMA before using this tool with the -z option on it.]]
+The -z option will zero out unallocated clusters. Always backup the IMA before using the -z option on it.]]
 if #arg<1 then print(arg[-1].." "..arg[0].." [-z] [FILE...]"..'\n\n'..H)os.exit(1)end
-function A()F={} for _,v in ipairs(arg)do if v=="-z" then Z=true else table.insert(F,v)end end end
 function R16(s,o)local a,b=s:byte(o,o+1)return a+b*256 end
 function R32(s,o)local a,b,c,d=s:byte(o,o+3)return a+b*256+c*65536+d*16777216 end
 function F12(f,o,s)f:seek("set",o)local fd,fat,mc=f:read(s),{},math.floor(s*8/12)
@@ -16,8 +15,9 @@ function FD(ts,rs,nf,sf,rd,sc)
 	local cc=math.floor((ts-rs-(nf*sf)-rd)/sc)
 	if cc<4085 then return 12 elseif cc<65525 then return 16 else return 32 end end
 function CC(fat,sc)
-	local chain,current={},sc
-	while current>=2 and current<0xFF8 do table.insert(chain,current)current=fat[current] end return chain end
+	local h,c={},sc
+	while c>=2 and c<0xFF8 do table.insert(h,c)c=fat[c] end return h
+end
 function FR(c)
 	table.sort(c)local ranges,i={},1
 	while i <=#c do
@@ -30,20 +30,17 @@ function DE(f,o,e,fat)
 	for _=1,e do
 		local en,fb=f:read(32)if not en then break end fb=en:byte(1)if fb==0 then break end
 		if fb~=229 and(en:byte(12)&8)==0 then
-			local n,x=en:sub(1,8):gsub("+$",""),en:sub(9,11):gsub("+$","")n=n..(x~=""and"."..x or"")
-			io.write(string.format("\t%12s: %s\n",n,FR(CC(fat,R16(en,27)))))end end end
+			local n,x=en:sub(1,8):gsub("+$",""),en:sub(9,11):gsub("+$","")
+			io.write(string.format("\t%8s %3s %s\n",n,x,FR(CC(fat,R16(en,27)))))end end end
 function FC(fat,f,st,s)
-	io.write("\n\t  Free Space: ")
-	local free,zero={},string.rep("\0",s)
-	for i=2,#fat do if fat[i]==0 then table.insert(free,i)if Z then local o=st+(i-2)*s f:seek("set",o)f:write(zero)end end end print(FR(free))end
-A()for _,file in ipairs(F)do
-	local f=io.open(file,(Z and"r+b"or"rb"))
-	if f then
-		print(file..":")
-		local boot=f:read(512)assert(boot:sub(1,1):byte()==0xEB or boot:sub(1,1):byte()==0xE9,"Invalid boot sector")
-		local bs,sc,rs,nf,re,ts,sf=R16(boot,12),boot:byte(14),R16(boot,15),boot:byte(17),R16(boot,18),R16(boot,19)or R32(boot,32),R16(boot,23)
-		local rd,fo,fs,ro=math.ceil(re*32/bs),rs*bs,sf*bs,(rs+nf*sf)*bs
-		local ft=FD(ts,rs,nf,sf,rd,bs)
+	local fr,z={},string.rep("\0",s)io.write("\n\tFree Space   ")
+	for i=2,#fat do if fat[i]==0 then table.insert(fr,i)if Z then local o=st+(i-2)*s f:seek("set",o)f:write(z)end end end print(FR(fr))end
+F={}for _,v in ipairs(arg)do if v=="-z" then Z=1 else table.insert(F,v)end end for _,file in ipairs(F)do
+local f=io.open(file,(Z and"r+b"or"rb"))if f then
+	print(file..":")
+	local b,o=f:read(512)o=b:sub(1,1):byte()if o==235 or o==233 then
+		local bs,sc,rs,nf,re,ts,sf=R16(b,12),b:byte(14),R16(b,15),b:byte(17),R16(b,18),R16(b,19)or R32(b,32),R16(b,23)
+		local rd,fo,fs,ro,ft=math.ceil(re*32/bs),rs*bs,sf*bs,(rs+nf*sf)*bs ft=FD(ts,rs,nf,sf,rd,bs)
 		print(string.format("\t       FAT type: FAT%s\n\t   Bytes/sector: %d\n\tSectors/cluster: %d\n\n",ft,bs,sc))
 		local fat=ft==12 and F12(f,fo,fs)or ft==16 and F16(f,fo,fs)or error("Non-FAT type")
-		DE(f,ro,re,fat)FC(fat,f,(rs+(nf*sf)+rd)*bs,sc*bs)f:close()print()end end
+		DE(f,ro,re,fat)FC(fat,f,(rs+(nf*sf)+rd)*bs,sc*bs)end f:close()print()end end