如果你已经安装了coreutils包，你通常可以使用readlink -f relative_file_name来检索绝对符号链接(解析所有符号链接)。

类似于@ernest-a的答案，但不影响$OLDPWD或定义一个新函数，您可以触发一个子shell (cd <path>;pwd)

$ pwd
/etc/apache2
$ cd ../cups 
$ cd -
/etc/apache2
$ (cd ~/..; pwd)
/Users
$ cd -
/etc/cups

如果你在Mac OS X上使用bash，它既没有realpath也没有readlink可以打印绝对路径，你可以选择编写自己的版本来打印它。 这是我的实现:

(纯bash)

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[*]}"
)
}

(用呆呆的)

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)
}

例子:

$ abspath I/am/.//..//the/./god/../of///.././war
/Users/leon/I/the/war

这是来自所有其他解决方案的链式解决方案，例如，当realpath失败时，要么是因为没有安装它，要么是因为它带着错误代码退出，那么，将尝试下一个解决方案，直到它获得正确的路径。

#!/bin/bash

function getabsolutepath() {
    local target;
    local changedir;
    local basedir;
    local firstattempt;

    target="${1}";
    if [ "$target" == "." ];
    then
        printf "%s" "$(pwd)";

    elif [ "$target" == ".." ];
    then
        printf "%s" "$(dirname "$(pwd)")";

    else
        changedir="$(dirname "${target}")" && basedir="$(basename "${target}")" && firstattempt="$(cd "${changedir}" && pwd)" && printf "%s/%s" "${firstattempt}" "${basedir}" && return 0;
        firstattempt="$(readlink -f "${target}")" && printf "%s" "${firstattempt}" && return 0;
        firstattempt="$(realpath "${target}")" && printf "%s" "${firstattempt}" && return 0;

        # If everything fails... TRHOW PYTHON ON IT!!!
        local fullpath;
        local pythoninterpreter;
        local pythonexecutables;
        local pythonlocations;

        pythoninterpreter="python";
        declare -a pythonlocations=("/usr/bin" "/bin");
        declare -a pythonexecutables=("python" "python2" "python3");

        for path in "${pythonlocations[@]}";
        do
            for executable in "${pythonexecutables[@]}";
            do
                fullpath="${path}/${executable}";

                if [[ -f "${fullpath}" ]];
                then
                    # printf "Found ${fullpath}\\n";
                    pythoninterpreter="${fullpath}";
                    break;
                fi;
            done;

            if [[ "${pythoninterpreter}" != "python" ]];
            then
                # printf "Breaking... ${pythoninterpreter}\\n"
                break;
            fi;
        done;

        firstattempt="$(${pythoninterpreter} -c "import os, sys; print( os.path.abspath( sys.argv[1] ) );" "${target}")" && printf "%s" "${firstattempt}" && return 0;
        # printf "Error: Could not determine the absolute path!\\n";
        return 1;
    fi
}

printf "\\nResults:\\n%s\\nExit: %s\\n" "$(getabsolutepath "./asdfasdf/ asdfasdf")" "${?}"

对@ernest-a相当不错的版本的改进:

absolute_path() {
    cd "$(dirname "$1")"
    case $(basename $1) in
        ..) echo "$(dirname $(pwd))";;
        .)  echo "$(pwd)";;
        *)  echo "$(pwd)/$(basename $1)";;
    esac
}

这正确地处理了路径的最后一个元素是..，在这种情况下，@ernest-a的答案中的“$(pwd)/$(basename“$1”)”将通过作为accurate_sub_path/spurious_subdirectory/…

恕我直言，最好的解决方案是在这里发布的:https://stackoverflow.com/a/3373298/9724628。

它确实需要python才能工作，但它似乎涵盖了所有或大部分边缘情况，是非常可移植的解决方案。

通过解析符号链接:

python -c "import os,sys; print(os.path.realpath(sys.argv[1]))" path/to/file

或者没有它:

python -c "import os,sys; print(os.path.abspath(sys.argv[1]))" path/to/file