v1.3

README.md

@@ -176,6 +176,8 @@ libc6-amd64_2.27-3ubuntu1_i386.so
 
 - v1.2 -- Updata install.sh. Now the installation can be finished in seconds.
 
+- v1.3 -- fix a bug about local libc with symbolic link. Thanks to [f0110vv3r](https://github.com/f0110vv3r)
+
 ### more
 - Though it works perfect on [libc-databases](https://github.com/niklasb/libc-database) now(*Alpha-v1.0*). But I'm not sure whether it works well on other libcs so issues are welcome.
 

install.sh

@@ -3,6 +3,6 @@ wget -q https://raw.githubusercontent.com/0x01f/main_arena_offset/master/main_ar
 sudo mv main_arena /usr/local/bin/main_arena
 sudo chmod +x /usr/local/bin/main_arena
 echo "Done! Enjoy it!"
-echo "Usage:"
+echo -n "Usage:"
 echo -e "\033[0;35m$\033[0m \033[01;31mmain_arena\033[0m \033[1;32myour_libc_path\033[0m"
 echo "Star it on github <https://github.com/0x01f/main_arena_offset> if you like it."

main_arena

@@ -2,8 +2,8 @@
 # set -eux
 
 :<<DESCRIPTION
-	This is a simple script to get main_arena offset of a given libc.
-	Usage: main_arena your_libc
+	This is a simple shell script to get main_arena offset of a given libc.
+	Usage: $ main_arena your_libc
 	avaiable on <https://github.com/0x01f/main_arena_offset>
 DESCRIPTION
 
@@ -58,17 +58,24 @@ function printInfo()
 getOffset
 function getOffset()
 {
-	mallocHook=$(objdump -j .data -d $1|grep __malloc_hook@ |cut -d " " -f 1)
+	libc=$1
+	# deal with local libc(in case of symbolic link)
+	if [[ $(file $libc) =~ "symbolic link" ]]
+	then
+		libc=$(dirname $libc)"/"$(readlink $libc)
+	fi
+
+	mallocHook=$(objdump -j .data -d $libc|grep __malloc_hook@ |cut -d " " -f 1)
 	let mallocHook=16#$mallocHook
 	# 32-bit
-	if [[ $(file $1) =~ "32-bit" ]]
+	if [[ $(file $libc) =~ "32-bit" ]]
 	then
 		let mainArena=($mallocHook+0x18)
 		printInfo "$mallocHook" $mainArena
 	fi
 
 	# 64-bit
-	reallocHook=$(objdump -j .data -d $1|grep __realloc_hook@ |cut -d " " -f 1)
+	reallocHook=$(objdump -j .data -d $libc|grep __realloc_hook@ |cut -d " " -f 1)
 	let reallocHook=16#$reallocHook
 	((offset=$mallocHook-$reallocHook))
 
@@ -77,6 +84,6 @@ function getOffset()
 }
 
 :<<get_result
-	get result.
+	get result by calling getOffset.
 get_result
 getOffset $1