如果您使用的是Mac OS X上的bash既不具有真实路径存在也没有了它的readlink可以打印的绝对路径，你可以有选择，只能自己编码的版本进行打印。这是我的实现：
（纯扑）
abspath(){
local thePath
if [[ ! "$1" =~ ^/ ]];then
thePath="$PWD/$1"
else
thePath="$1"
fi
echo "$thePath"|(
IFS=/
read -a parr
declare -a outp
for i in "${parr[@]}";do
case "$i" in
''|.) continue ;;
..)
len=${#outp[@]}
if ((len==0));then
continue
else
unset outp[$((len-1))]
fi
;;
*)
len=${#outp[@]}
outp[$len]="$i"
;;
esac
done
echo /"${outp[*]}"
)
}
（使用gawk）
abspath_gawk() {
if [[ -n "$1" ]];then
echo $1|gawk '{
if(substr($0,1,1) != "/"){
path = ENVIRON["PWD"]"/"$0
} else path = $0
split(path, a, "/")
n = asorti(a, b,"@ind_num_asc")
for(i in a){
if(a[i]=="" || a[i]=="."){
delete a[i]
}
}
n = asorti(a, b, "@ind_num_asc")
m = 0
while(m!=n){
m = n
for(i=1;i<=n;i++){
if(a[b[i]]==".."){
if(b[i-1] in a){
delete a[b[i-1]]
delete a[b[i]]
n = asorti(a, b, "@ind_num_asc")
break
} else exit 1
}
}
}
n = asorti(a, b, "@ind_num_asc")
if(n==0){
printf "/"
} else {
for(i=1;i<=n;i++){
printf "/"a[b[i]]
}
}
}'
fi
}
（纯bsd awk）
#!/usr/bin/env awk -f
function abspath(path, i,j,n,a,b,back,out){
if(substr(path,1,1) != "/"){
path = ENVIRON["PWD"]"/"path
}
split(path, a, "/")
n = length(a)
for(i=1;i<=n;i++){
if(a[i]==""||a[i]=="."){
continue
}
a[++j]=a[i]
}
for(i=j+1;i<=n;i++){
delete a[i]
}
j=0
for(i=length(a);i>=1;i--){
if(back==0){
if(a[i]==".."){
back++
continue
} else {
b[++j]=a[i]
}
} else {
if(a[i]==".."){
back++
continue
} else {
back--
continue
}
}
}
if(length(b)==0){
return "/"
} else {
for(i=length(b);i>=1;i--){
out=out"/"b[i]
}
return out
}
}
BEGIN{
if(ARGC>1){
for(k=1;k<ARGC;k++){
print abspath(ARGV[k])
}
exit
}
}
{
print abspath($0)
}
例：
$ abspath I/am/.//..//the/./god/../of///.././war
/Users/leon/I/the/war