Shell - Get the absolute path of a file

 

zzh@ZZHPC:~/aaa$ cat a.sh
echo ${BASH_SOURCE[0]}
abpath=$(realpath ${BASH_SOURCE[0]})
echo $abpath
dir=$(dirname $abpath)
echo $dir

 

zzh@ZZHPC:~/aaa$ ./a.sh
./a.sh
/home/zzh/aaa/a.sh
/home/zzh/aaa