带有OS X的bash脚本绝对路径

有一个 realpath() C函数可以完成这项工作,但在命令行上看不到任何可用的内容。这里有一个快速而肮脏的替代品:

#!/bin/bash

realpath() {
    [[ $1 = /* ]] && echo "$1" || echo "$PWD/${1#./}"
}

realpath "$0"

如果路径以 / . 如果不是,它必须是一个相对路径,因此它会提前 $PWD 到前面去。这个 #./ 零件剥离 ./ 从前面 $1 .

这三个简单的步骤将解决这一问题和许多其他OS X问题:

1. 安装 Homebrew
2. brew install coreutils
3. grealpath .

(3)可改为公正 realpath ,见(2)输出

呃。我发现之前的答案有点欠缺,原因有几个:特别是,它们不能解析多个层次的符号链接,而且它们是非常“bash-y”。虽然最初的问题确实明确要求“bash脚本”,但它也提到了mac os x的类似bsd的非GNU readlink . 所以这里有一个合理的可移植性的尝试(我用bash检查了它作为'sh'和dash),解析任意数量的符号链接;它也应该在路径中使用空格,尽管我不确定是否存在空格(实用程序本身的基名),那么也许,嗯,避免这样做?

#!/bin/sh
realpath() {
  OURPWD=$PWD
  cd "$(dirname "$1")"
  LINK=$(readlink "$(basename "$1")")
  while [ "$LINK" ]; do
    cd "$(dirname "$LINK")"
    LINK=$(readlink "$(basename "$1")")
  done
  REALPATH="$PWD/$(basename "$1")"
  cd "$OURPWD"
  echo "$REALPATH"
}
realpath "$@"

希望这对某人有用。

python解决方案的一个更友好的命令行变体:

python -c "import os; print(os.path.realpath('$1'))"

我正在寻找一个可用于系统配置脚本的解决方案,即在安装自制之前运行。由于缺乏适当的解决方案,我只需将任务卸载到跨平台语言,例如Perl:

script_abspath=$(perl -e 'use Cwd "abs_path"; print abs_path(@ARGV[0])' -- "$0")

通常我们真正想要的是包含目录:

here=$(perl -e 'use File::Basename; use Cwd "abs_path"; print dirname(abs_path(@ARGV[0]));' -- "$0")

因为有一个 realpath 正如其他人指出的那样:

// realpath.c
#include <stdio.h>
#include <stdlib.h>

int main (int argc, char* argv[])
{
  if (argc > 1) {
    for (int argIter = 1; argIter < argc; ++argIter) {
      char *resolved_path_buffer = NULL;
      char *result = realpath(argv[argIter], resolved_path_buffer);

      puts(result);

      if (result != NULL) {
        free(result);
      }
    }
  }

  return 0;
}

Makefile:

#Makefile
OBJ = realpath.o

%.o: %.c
      $(CC) -c -o $@ $< $(CFLAGS)

realpath: $(OBJ)
      gcc -o $@ $^ $(CFLAGS)

然后用编译 make 并与以下对象建立软链接:
ln -s $(pwd)/realpath /usr/local/bin/realpath

使用python获取:

#!/usr/bin/env python
import os
import sys

print(os.path.realpath(sys.argv[1]))

正如你在上面看到的,大约6个月前我拍了一张照片。我完全 忘了它,直到我发现自己又需要类似的东西。我是 完全震惊 我一直在教书 我自己已经花了大约一年的时间集中编写代码了,但我经常觉得 也许在最坏的时候我什么都没学到。

我会删除上面的“解决方案”,但我真的希望它是 在过去的几个月里我真正学到了多少。

但我离题了。我昨天晚上坐下来,把一切都解决了。解释 这些评论应该足够了。如果你想追踪副本,我会继续 继续工作, you can follow this gist. 这可能是你需要的。

#!/bin/sh # dash bash ksh # !zsh (issues). G. Nixon, 12/2013. Public domain.

## 'linkread' or 'fullpath' or (you choose) is a little tool to recursively
## dereference symbolic links (ala 'readlink') until the originating file
## is found. This is effectively the same function provided in stdlib.h as
## 'realpath' and on the command line in GNU 'readlink -f'.

## Neither of these tools, however, are particularly accessible on the many
## systems that do not have the GNU implementation of readlink, nor ship
## with a system compiler (not to mention the requisite knowledge of C).

## This script is written with portability and (to the extent possible, speed)
## in mind, hence the use of printf for echo and case statements where they
## can be substituded for test, though I've had to scale back a bit on that.

## It is (to the best of my knowledge) written in standard POSIX shell, and
## has been tested with bash-as-bin-sh, dash, and ksh93. zsh seems to have
## issues with it, though I'm not sure why; so probably best to avoid for now.

## Particularly useful (in fact, the reason I wrote this) is the fact that
## it can be used within a shell script to find the path of the script itself.
## (I am sure the shell knows this already; but most likely for the sake of
## security it is not made readily available. The implementation of "$0"
## specificies that the $0 must be the location of **last** symbolic link in
## a chain, or wherever it resides in the path.) This can be used for some
## ...interesting things, like self-duplicating and self-modifiying scripts.

## Currently supported are three errors: whether the file specified exists
## (ala ENOENT), whether its target exists/is accessible; and the special
## case of when a sybolic link references itself "foo -> foo": a common error
## for beginners, since 'ln' does not produce an error if the order of link
## and target are reversed on the command line. (See POSIX signal ELOOP.)

## It would probably be rather simple to write to use this as a basis for
## a pure shell implementation of the 'symlinks' util included with Linux.

## As an aside, the amount of code below **completely** belies the amount
## effort it took to get this right -- but I guess that's coding for you.

##===-------------------------------------------------------------------===##

for argv; do :; done # Last parameter on command line, for options parsing.

## Error messages. Use functions so that we can sub in when the error occurs.

recurses(){ printf "Self-referential:\n\t$argv ->\n\t$argv\n" ;}
dangling(){ printf "Broken symlink:\n\t$argv ->\n\t"$(readlink "$argv")"\n" ;}
errnoent(){ printf "No such file: "$@"\n" ;} # Borrow a horrible signal name.

# Probably best not to install as 'pathfull', if you can avoid it.

pathfull(){ cd "$(dirname "$@")"; link="$(readlink "$(basename "$@")")"

## 'test and 'ls' report different status for bad symlinks, so we use this.

 if [ ! -e "$@" ]; then if $(ls -d "$@" 2>/dev/null) 2>/dev/null;  then
    errnoent 1>&2; exit 1; elif [ ! -e "$@" -a "$link" = "$@" ];   then
    recurses 1>&2; exit 1; elif [ ! -e "$@" ] && [ ! -z "$link" ]; then
    dangling 1>&2; exit 1; fi
 fi

## Not a link, but there might be one in the path, so 'cd' and 'pwd'.

 if [ -z "$link" ]; then if [ "$(dirname "$@" | cut -c1)" = '/' ]; then
   printf "$@\n"; exit 0; else printf "$(pwd)/$(basename "$@")\n"; fi; exit 0
 fi

## Walk the symlinks back to the origin. Calls itself recursivly as needed.

 while [ "$link" ]; do
   cd "$(dirname "$link")"; newlink="$(readlink "$(basename "$link")")"
   case "$newlink" in
    "$link") dangling 1>&2 && exit 1                                       ;;
         '') printf "$(pwd)/$(basename "$link")\n"; exit 0                 ;;
          *) link="$newlink" && pathfull "$link"                           ;;
   esac
 done
 printf "$(pwd)/$(basename "$newlink")\n"
}

## Demo. Install somewhere deep in the filesystem, then symlink somewhere 
## else, symlink again (maybe with a different name) elsewhere, and link
## back into the directory you started in (or something.) The absolute path
## of the script will always be reported in the usage, along with "$0".

if [ -z "$argv" ]; then scriptname="$(pathfull "$0")"

# Yay ANSI l33t codes! Fancy.
 printf "\n\033[3mfrom/as: \033[4m$0\033[0m\n\n\033[1mUSAGE:\033[0m   "
 printf "\033[4m$scriptname\033[24m [ link | file | dir ]\n\n         "
 printf "Recursive readlink for the authoritative file, symlink after "
 printf "symlink.\n\n\n         \033[4m$scriptname\033[24m\n\n        "
 printf " From within an invocation of a script, locate the script's "
 printf "own file\n         (no matter where it has been linked or "
 printf "from where it is being called).\n\n"

else pathfull "$@"
fi

Mac OS X的realpath

realpath() {
    path=`eval echo "$1"`
    folder=$(dirname "$path")
    echo $(cd "$folder"; pwd)/$(basename "$path"); 
}

具有相关路径的示例:

realpath "../scripts/test.sh"

主文件夹示例

realpath "~/Test/../Test/scripts/test.sh"

基于与评论者的沟通,我同意这是非常困难的,没有繁琐的方式来实现一个真正的路径行为完全相同的Ubuntu。

但下面的版本,可以处理角箱的最佳答案,不能满足我对MacBook的日常需求。将此代码放入~/.bashrc并记住:

• arg只能是1个文件或目录,没有通配符
• 目录或文件名中没有空格
• 至少存在文件或目录的父目录
• 请随意使用。…/东西,这些是安全的

    # 1. if is a dir, try cd and pwd
    # 2. if is a file, try cd its parent and concat dir+file
    realpath() {
     [ "$1" = "" ] && return 1

     dir=`dirname "$1"`
     file=`basename "$1"`

     last=`pwd`

     [ -d "$dir" ] && cd $dir || return 1
     if [ -d "$file" ];
     then
       # case 1
       cd $file && pwd || return 1
     else
       # case 2
       echo `pwd`/$file | sed 's/\/\//\//g'
     fi

     cd $last
    }