例子:
absolute="/foo/bar"
current="/foo/baz/foo"
# Magic
relative="../../bar"
我如何创造魔法(希望不是太复杂的代码…)?
例子:
absolute="/foo/bar"
current="/foo/baz/foo"
# Magic
relative="../../bar"
我如何创造魔法(希望不是太复杂的代码…)?
当前回答
test.sh:
#!/bin/bash
cd /home/ubuntu
touch blah
TEST=/home/ubuntu/.//blah
echo TEST=$TEST
TMP=$(readlink -e "$TEST")
echo TMP=$TMP
REL=${TMP#$(pwd)/}
echo REL=$REL
测试:
$ ./test.sh
TEST=/home/ubuntu/.//blah
TMP=/home/ubuntu/blah
REL=blah
其他回答
下面是一个shell脚本,它可以在不调用其他程序的情况下完成:
#! /bin/env bash
#bash script to find the relative path between two directories
mydir=${0%/}
mydir=${0%/*}
creadlink="$mydir/creadlink"
shopt -s extglob
relpath_ () {
path1=$("$creadlink" "$1")
path2=$("$creadlink" "$2")
orig1=$path1
path1=${path1%/}/
path2=${path2%/}/
while :; do
if test ! "$path1"; then
break
fi
part1=${path2#$path1}
if test "${part1#/}" = "$part1"; then
path1=${path1%/*}
continue
fi
if test "${path2#$path1}" = "$path2"; then
path1=${path1%/*}
continue
fi
break
done
part1=$path1
path1=${orig1#$part1}
depth=${path1//+([^\/])/..}
path1=${path2#$path1}
path1=${depth}${path2#$part1}
path1=${path1##+(\/)}
path1=${path1%/}
if test ! "$path1"; then
path1=.
fi
printf "$path1"
}
relpath_test () {
res=$(relpath_ /path1/to/dir1 /path1/to/dir2 )
expected='../dir2'
test_results "$res" "$expected"
res=$(relpath_ / /path1/to/dir2 )
expected='path1/to/dir2'
test_results "$res" "$expected"
res=$(relpath_ /path1/to/dir2 / )
expected='../../..'
test_results "$res" "$expected"
res=$(relpath_ / / )
expected='.'
test_results "$res" "$expected"
res=$(relpath_ /path/to/dir2/dir3 /path/to/dir1/dir4/dir4a )
expected='../../dir1/dir4/dir4a'
test_results "$res" "$expected"
res=$(relpath_ /path/to/dir1/dir4/dir4a /path/to/dir2/dir3 )
expected='../../../dir2/dir3'
test_results "$res" "$expected"
#res=$(relpath_ . /path/to/dir2/dir3 )
#expected='../../../dir2/dir3'
#test_results "$res" "$expected"
}
test_results () {
if test ! "$1" = "$2"; then
printf 'failed!\nresult:\nX%sX\nexpected:\nX%sX\n\n' "$@"
fi
}
#relpath_test
来源:http://www.ynform.org/w/Pub/Relpath
假设您已经安装了:bash、pwd、dirname、echo;relpath是
#!/bin/bash
s=$(cd ${1%%/};pwd); d=$(cd $2;pwd); b=; while [ "${d#$s/}" == "${d}" ]
do s=$(dirname $s);b="../${b}"; done; echo ${b}${d#$s/}
我从pini和其他一些想法中得到了答案
注意:这要求两个路径都是现有文件夹。文件将无法工作。
这个答案并没有解决问题的Bash部分,但是因为我试图使用这个问题中的答案在Emacs中实现这个功能,所以我就把它扔到那里。
Emacs实际上有一个开箱即用的函数:
ELISP> (file-relative-name "/a/b/c" "/a/b/c")
"."
ELISP> (file-relative-name "/a/b/c" "/a/b")
"c"
ELISP> (file-relative-name "/a/b/c" "/c/b")
"../../a/b/c"
我猜这个也可以…(自带内置测试):)
好吧,预计会有一些开销,但我们在这里做的是伯恩壳!;)
#!/bin/sh
#
# Finding the relative path to a certain file ($2), given the absolute path ($1)
# (available here too http://pastebin.com/tWWqA8aB)
#
relpath () {
local FROM="$1"
local TO="`dirname $2`"
local FILE="`basename $2`"
local DEBUG="$3"
local FROMREL=""
local FROMUP="$FROM"
while [ "$FROMUP" != "/" ]; do
local TOUP="$TO"
local TOREL=""
while [ "$TOUP" != "/" ]; do
[ -z "$DEBUG" ] || echo 1>&2 "$DEBUG$FROMUP =?= $TOUP"
if [ "$FROMUP" = "$TOUP" ]; then
echo "${FROMREL:-.}/$TOREL${TOREL:+/}$FILE"
return 0
fi
TOREL="`basename $TOUP`${TOREL:+/}$TOREL"
TOUP="`dirname $TOUP`"
done
FROMREL="..${FROMREL:+/}$FROMREL"
FROMUP="`dirname $FROMUP`"
done
echo "${FROMREL:-.}${TOREL:+/}$TOREL/$FILE"
return 0
}
relpathshow () {
echo " - target $2"
echo " from $1"
echo " ------"
echo " => `relpath $1 $2 ' '`"
echo ""
}
# If given 2 arguments, do as said...
if [ -n "$2" ]; then
relpath $1 $2
# If only one given, then assume current directory
elif [ -n "$1" ]; then
relpath `pwd` $1
# Otherwise perform a set of built-in tests to confirm the validity of the method! ;)
else
relpathshow /usr/share/emacs22/site-lisp/emacs-goodies-el \
/usr/share/emacs22/site-lisp/emacs-goodies-el/filladapt.el
relpathshow /usr/share/emacs23/site-lisp/emacs-goodies-el \
/usr/share/emacs22/site-lisp/emacs-goodies-el/filladapt.el
relpathshow /usr/bin \
/usr/share/emacs22/site-lisp/emacs-goodies-el/filladapt.el
relpathshow /usr/bin \
/usr/share/emacs22/site-lisp/emacs-goodies-el/filladapt.el
relpathshow /usr/bin/share/emacs22/site-lisp/emacs-goodies-el \
/etc/motd
relpathshow / \
/initrd.img
fi
我使用的macOS默认情况下没有realpath命令,所以我做了一个纯bash函数来计算它。
#!/bin/bash
##
# print a relative path from "source folder" to "target file"
#
# params:
# $1 - target file, can be a relative path or an absolute path.
# $2 - source folder, can be a relative path or an absolute path.
#
# test:
# $ mkdir -p ~/A/B/C/D; touch ~/A/B/C/D/testfile.txt; touch ~/A/B/testfile.txt
#
# $ getRelativePath ~/A/B/C/D/testfile.txt ~/A/B
# $ C/D/testfile.txt
#
# $ getRelativePath ~/A/B/testfile.txt ~/A/B/C
# $ ../testfile.txt
#
# $ getRelativePath ~/A/B/testfile.txt /
# $ home/bunnier/A/B/testfile.txt
#
function getRelativePath(){
local targetFilename=$(basename $1)
local targetFolder=$(cd $(dirname $1);pwd) # absolute target folder path
local currentFolder=$(cd $2;pwd) # absulute source folder
local result=.
while [ "$currentFolder" != "$targetFolder" ];do
if [[ "$targetFolder" =~ "$currentFolder"* ]];then
pointSegment=${targetFolder#$currentFolder}
result=$result/${pointSegment#/}
break
fi
result="$result"/..
currentFolder=$(dirname $currentFolder)
done
result=$result/$targetFilename
echo ${result#./}
}