不完全是一个答案，但可能是一个后续问题(最初的问题不明确):

如果你真的想遵循符号链接，Readlink是很好的。但也有一个用例仅仅是正常化。/和../和//序列，这可以纯语法地完成，而不需要规范化符号链接。Readlink做不到这一点，realpath也不行。

for f in $paths; do (cd $f; pwd); done

适用于现有路径，但不适用于其他路径。

sed脚本似乎是一个不错的选择，除了不能迭代地替换序列(/foo/bar/baz/../..)- > / foo / bar / . .-> /foo)没有使用像Perl这样的东西，这在所有系统上都是不安全的，或者使用一些丑陋的循环来比较sed的输出和它的输入。

FWIW，使用Java (JDK 6+)的一行程序:

jrunscript -e 'for (var i = 0; i < arguments.length; i++) {println(new java.io.File(new java.io.File(arguments[i]).toURI().normalize()))}' $paths

我需要一个同时满足这三点的解决方案:

在普通mac上工作。realpath和readlink -f是插件 解决符号链接 有错误处理

没有一个人的答案同时包含了第一条和第二条。我加了第三条是为了让其他人不用再剃牦牛了。

#!/bin/bash

P="${1?Specify a file path}"

[ -e "$P" ] || { echo "File does not exist: $P"; exit 1; }

while [ -h "$P" ] ; do
    ls="$(ls -ld "$P")"
    link="$(expr "$ls" : '.*-> \(.*\)$')"
    expr "$link" : '/.*' > /dev/null &&
        P="$link" ||
        P="$(dirname "$P")/$link"
done
echo "$(cd "$(dirname "$P")"; pwd)/$(basename "$P")"

下面是一个简短的测试用例，在路径中有一些扭曲的空格，以充分练习引用

mkdir -p "/tmp/test/ first path "
mkdir -p "/tmp/test/ second path "
echo "hello" > "/tmp/test/ first path / red .txt "
ln -s "/tmp/test/ first path / red .txt " "/tmp/test/ second path / green .txt "

cd  "/tmp/test/ second path "
fullpath " green .txt "
cat " green .txt "

如果你只想规范化一个路径，不管是否存在，不涉及文件系统，不解析任何链接，也不使用外部utils，这里有一个从Python的posixpath.normpath转换而来的纯Bash函数。

#!/usr/bin/env bash

# Normalize path, eliminating double slashes, etc.
# Usage: new_path="$(normpath "${old_path}")"
# Translated from Python's posixpath.normpath:
# https://github.com/python/cpython/blob/master/Lib/posixpath.py#L337
normpath() {
  local IFS=/ initial_slashes='' comp comps=()
  if [[ $1 == /* ]]; then
    initial_slashes='/'
    [[ $1 == //* && $1 != ///* ]] && initial_slashes='//'
  fi
  for comp in $1; do
    [[ -z ${comp} || ${comp} == '.' ]] && continue
    if [[ ${comp} != '..' || (-z ${initial_slashes} && ${#comps[@]} -eq 0) || (\
      ${#comps[@]} -gt 0 && ${comps[-1]} == '..') ]]; then
      comps+=("${comp}")
    elif ((${#comps[@]})); then
      unset 'comps[-1]'
    fi
  done
  comp="${initial_slashes}${comps[*]}"
  printf '%s\n' "${comp:-.}"
}

例子:

new_path="$(normpath '/foo/bar/..')"
echo "${new_path}"
# /foo

normpath "relative/path/with trailing slashs////"
# relative/path/with trailing slashs

normpath "////a/../lot/././/mess////./here/./../"
# /lot/mess

normpath ""
# .
# (empty path resolved to dot)

Personally, I cannot understand why Shell, a language often used for manipulating files, doesn't offer basic functions to deal with paths. In python, we have nice libraries like os.path or pathlib, which offers a whole bunch of tools to extract filename, extension, basename, path segments, split or join paths, to get absolute or normalized paths, to determine relations between paths, to do everything without much brain. And they take care of edge cases, and they're reliable. In Shell, to do any of these, either we call external executables, or we have to reinvent wheels with these extremely rudimentary and arcane syntaxes...

realpath试试。以下是全文来源，特此捐赠给公众领域。

// realpath.c: display the absolute path to a file or directory.
// Adam Liss, August, 2007
// This program is provided "as-is" to the public domain, without express or
// implied warranty, for any non-profit use, provided this notice is maintained.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libgen.h>   
#include <limits.h>

static char *s_pMyName;
void usage(void);

int main(int argc, char *argv[])
{
    char
        sPath[PATH_MAX];


    s_pMyName = strdup(basename(argv[0]));

    if (argc < 2)
        usage();

    printf("%s\n", realpath(argv[1], sPath));
    return 0;
}    

void usage(void)
{
    fprintf(stderr, "usage: %s PATH\n", s_pMyName);
    exit(1);
}

我不知道是否有直接的bash命令可以做到这一点，但我通常会这样做

normalDir="`cd "${dirToNormalize}";pwd`"
echo "${normalDir}"

而且效果很好。

如果您想要从路径中删除部分文件名，“dirname”和“basename”是您的朋友，“realpath”也很方便。

dirname /foo/bar/baz 
# /foo/bar 
basename /foo/bar/baz
# baz
dirname $( dirname  /foo/bar/baz  ) 
# /foo 
realpath ../foo
# ../foo: No such file or directory
realpath /tmp/../tmp/../tmp
# /tmp

realpath替代品

如果您的shell不支持realpath，您可以尝试

readlink -f /path/here/.. 

Also

readlink -m /path/there/../../ 

工作原理与

realpath -s /path/here/../../

在这种情况下，路径不需要存在就可以被规范化。