Based on loveborg's excellent python snippet, I wrote this:
#!/bin/sh
# Version of readlink that follows links to the end; good for Mac OS X
for file in "$@"; do
while [ -h "$file" ]; do
l=`readlink $file`
case "$l" in
/*) file="$l";;
*) file=`dirname "$file"`/"$l"
esac
done
#echo $file
python -c "import os,sys; print os.path.abspath(sys.argv[1])" "$file"
done
I don't know if there is a direct bash command to do this, but I usually do
normalDir="`cd "${dirToNormalize}";pwd`"
echo "${normalDir}"
and it works well.
I'm late to the party, but this is the solution I've crafted after reading a bunch of threads like this:
resolve_dir() {
(builtin cd `dirname "${1/#~/$HOME}"`'/'`basename "${1/#~/$HOME}"` 2>/dev/null; if [ $? -eq 0 ]; then pwd; fi)
}
This will resolve the absolute path of $1, play nice with ~, keep symlinks in the path where they are, and it won't mess with your directory stack. It returns the full path or nothing if it doesn't exist. It expects $1 to be a directory and will probably fail if it's not, but that's an easy check to do yourself.
I needed a solution that would do all three:
realpath and readlink -f are addonsNone of the answers had both #1 and #2. I added #3 to save others any further yak-shaving.
#!/bin/bash
P="${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 "$P")"
Here is a short test case with some twisted spaces in the paths to fully exercise the quoting
mkdir -p "/tmp/test/ first path "
mkdir -p "/tmp/test/ second path "
echo "hello" > "/tmp/test/ first path / red .txt "
ln -s "/tmp/test/ first path / red .txt " "/tmp/test/ second path / green .txt "
cd "/tmp/test/ second path "
fullpath " green .txt "
cat " green .txt "
Based on loveborg's excellent python snippet, I wrote this:
#!/bin/sh
# Version of readlink that follows links to the end; good for Mac OS X
for file in "$@"; do
while [ -h "$file" ]; do
l=`readlink $file`
case "$l" in
/*) file="$l";;
*) file=`dirname "$file"`/"$l"
esac
done
#echo $file
python -c "import os,sys; print os.path.abspath(sys.argv[1])" "$file"
done
FILEPATH="file.txt"
echo $(realpath $(dirname $FILEPATH))/$(basename $FILEPATH)
This works even if the file doesn't exist. It does require the directory containing the file to exist.
Try realpath. Below is the source in its entirety, hereby donated to the public domain.
// realpath.c: display the absolute path to a file or directory.
// Adam Liss, August, 2007
// This program is provided "as-is" to the public domain, without express or
// implied warranty, for any non-profit use, provided this notice is maintained.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libgen.h>
#include <limits.h>
static char *s_pMyName;
void usage(void);
int main(int argc, char *argv[])
{
char
sPath[PATH_MAX];
s_pMyName = strdup(basename(argv[0]));
if (argc < 2)
usage();
printf("%s\n", realpath(argv[1], sPath));
return 0;
}
void usage(void)
{
fprintf(stderr, "usage: %s PATH\n", s_pMyName);
exit(1);
}
I discovered today that you can use the stat command to resolve paths.
So for a directory like "~/Documents":
You can run this:
stat -f %N ~/Documents
To get the full path:
/Users/me/Documents
For symlinks, you can use the %Y format option:
stat -f %Y example_symlink
Which might return a result like:
/usr/local/sbin/example_symlink
The formatting options might be different on other versions of *NIX but these worked for me on OSX.
Old question, but there is much simpler way if you are dealing with full path names at the shell level:
abspath="$( cd "$path" && pwd )"
As the cd happens in a subshell it does not impact the main script.
Two variations, supposing your shell built-in commands accept -L and -P, are:
abspath="$( cd -P "$path" && pwd -P )" #physical path with resolved symlinks abspath="$( cd -L "$path" && pwd -L )" #logical path preserving symlinks
Personally, I rarely need this later approach unless I'm fascinated with symbolic links for some reason.
FYI: variation on obtaining the starting directory of a script which works even if the script changes it's current directory later on.
name0="$(basename "$0")"; #base name of script dir0="$( cd "$( dirname "$0" )" && pwd )"; #absolute starting dir
The use of CD assures you always have the absolute directory, even if the script is run by commands such as ./script.sh which, without the cd/pwd, often gives just .. Useless if the script does a cd later on.
I know this is an ancient question. I'm still offering an alternative. Recently I met the same issue and found no existing and portable command to do that. So I wrote the following shell script which includes a function that can do the trick.
#! /bin/sh
function normalize {
local rc=0
local ret
if [ $# -gt 0 ] ; then
# invalid
if [ "x`echo $1 | grep -E '^/\.\.'`" != "x" ] ; then
echo $1
return -1
fi
# convert to absolute path
if [ "x`echo $1 | grep -E '^\/'`" == "x" ] ; then
normalize "`pwd`/$1"
return $?
fi
ret=`echo $1 | sed 's;/\.\($\|/\);/;g' | sed 's;/[^/]*[^/.]\+[^/]*/\.\.\($\|/\);/;g'`
else
read line
normalize "$line"
return $?
fi
if [ "x`echo $ret | grep -E '/\.\.?(/|$)'`" != "x" ] ; then
ret=`normalize "$ret"`
rc=$?
fi
echo "$ret"
return $rc
}
https://gist.github.com/bestofsong/8830bdf3e5eb9461d27313c3c282868c
The problem with realpath is that it is not available on BSD (or OSX for that matter). Here is a simple recipe extracted from a rather old (2009) article from Linux Journal, that is quite portable:
function normpath() {
# Remove all /./ sequences.
local path=${1//\/.\//\/}
# Remove dir/.. sequences.
while [[ $path =~ ([^/][^/]*/\.\./) ]]; do
path=${path/${BASH_REMATCH[0]}/}
done
echo $path
}
Notice this variant also does not require the path to exist.
Not exactly an answer but perhaps a follow-up question (original question was not explicit):
readlink is fine if you actually want to follow symlinks. But there is also a use case for merely normalizing ./ and ../ and // sequences, which can be done purely syntactically, without canonicalizing symlinks. readlink is no good for this, and neither is realpath.
for f in $paths; do (cd $f; pwd); done
works for existing paths, but breaks for others.
A sed script would seem to be a good bet, except that you cannot iteratively replace sequences (/foo/bar/baz/../.. -> /foo/bar/.. -> /foo) without using something like Perl, which is not safe to assume on all systems, or using some ugly loop to compare the output of sed to its input.
FWIW, a one-liner using Java (JDK 6+):
jrunscript -e 'for (var i = 0; i < arguments.length; i++) {println(new java.io.File(new java.io.File(arguments[i]).toURI().normalize()))}' $paths
A simple solution using node.js:
#!/usr/bin/env node
process.stdout.write(require('path').resolve(process.argv[2]));
Use the readlink utility from the coreutils package.
MY_PATH=$(readlink -f "$0")
FILEPATH="file.txt"
echo $(realpath $(dirname $FILEPATH))/$(basename $FILEPATH)
This works even if the file doesn't exist. It does require the directory containing the file to exist.
The problem with realpath is that it is not available on BSD (or OSX for that matter). Here is a simple recipe extracted from a rather old (2009) article from Linux Journal, that is quite portable:
function normpath() {
# Remove all /./ sequences.
local path=${1//\/.\//\/}
# Remove dir/.. sequences.
while [[ $path =~ ([^/][^/]*/\.\./) ]]; do
path=${path/${BASH_REMATCH[0]}/}
done
echo $path
}
Notice this variant also does not require the path to exist.
Try realpath. Below is the source in its entirety, hereby donated to the public domain.
// 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);
}
My recent solution was:
pushd foo/bar/..
dir=`pwd`
popd
Based on the answer of Tim Whitcomb.
My recent solution was:
pushd foo/bar/..
dir=`pwd`
popd
Based on the answer of Tim Whitcomb.
Talkative, and a bit late answer. I need to write one since I'm stuck on older RHEL4/5. I handles absolute and relative links, and simplifies //, /./ and somedir/../ entries.
test -x /usr/bin/readlink || readlink () {
echo $(/bin/ls -l $1 | /bin/cut -d'>' -f 2)
}
test -x /usr/bin/realpath || realpath () {
local PATH=/bin:/usr/bin
local inputpath=$1
local changemade=1
while [ $changemade -ne 0 ]
do
changemade=0
local realpath=""
local token=
for token in ${inputpath//\// }
do
case $token in
""|".") # noop
;;
"..") # up one directory
changemade=1
realpath=$(dirname $realpath)
;;
*)
if [ -h $realpath/$token ]
then
changemade=1
target=`readlink $realpath/$token`
if [ "${target:0:1}" = '/' ]
then
realpath=$target
else
realpath="$realpath/$target"
fi
else
realpath="$realpath/$token"
fi
;;
esac
done
inputpath=$realpath
done
echo $realpath
}
mkdir -p /tmp/bar
(cd /tmp ; ln -s /tmp/bar foo; ln -s ../.././usr /tmp/bar/link2usr)
echo `realpath /tmp/foo`
As Adam Liss noted realpath is not bundled with every distribution. Which is a shame, because it is the best solution. The provided source code is great, and I will probably start using it now. Here is what I have been using until now, which I share here just for completeness:
get_abs_path() {
local PARENT_DIR=$(dirname "$1")
cd "$PARENT_DIR"
local ABS_PATH="$(pwd)"/"$(basename "$1")"
cd - >/dev/null
echo "$ABS_PATH"
}
If you want it to resolve symlinks, just replace pwd with pwd -P.
readlink is the bash standard for obtaining the absolute path. It also has the advantage of returning empty strings if paths or a path doesn't exist (given the flags to do so).
To get the absolute path to a directory that may or may not exist, but who's parents do exist, use:
abspath=$(readlink -f $path)
To get the absolute path to a directory that must exist along with all parents:
abspath=$(readlink -e $path)
To canonicalise the given path and follow symlinks if they happen to exist, but otherwise ignore missing directories and just return the path anyway, it's:
abspath=$(readlink -m $path)
The only downside is that readlink will follow links. If you do not want to follow links, you can use this alternative convention:
abspath=$(cd ${path%/*} && echo $PWD/${path##*/})
That will chdir to the directory part of $path and print the current directory along with the file part of $path. If it fails to chdir, you get an empty string and an error on stderr.
A simple solution using node.js:
#!/usr/bin/env node
process.stdout.write(require('path').resolve(process.argv[2]));
I made a builtin-only function to handle this with a focus on highest possible performance (for fun). It does not resolve symlinks, so it is basically the same as realpath -sm.
## A bash-only mimic of `realpath -sm`.
## Give it path[s] as argument[s] and it will convert them to clean absolute paths
abspath () {
${*+false} && { >&2 echo $FUNCNAME: missing operand; return 1; };
local c s p IFS='/'; ## path chunk, absolute path, input path, IFS for splitting paths into chunks
local -i r=0; ## return value
for p in "$@"; do
case "$p" in ## Check for leading backslashes, identify relative/absolute path
'') ((r|=1)); continue;;
//[!/]*) >&2 echo "paths =~ ^//[^/]* are impl-defined; not my problem"; ((r|=2)); continue;;
/*) ;;
*) p="$PWD/$p";; ## Prepend the current directory to form an absolute path
esac
s='';
for c in $p; do ## Let IFS split the path at '/'s
case $c in ### NOTE: IFS is '/'; so no quotes needed here
''|.) ;; ## Skip duplicate '/'s and '/./'s
..) s="${s%/*}";; ## Trim the previous addition to the absolute path string
*) s+=/$c;; ### NOTE: No quotes here intentionally. They make no difference, it seems
esac;
done;
echo "${s:-/}"; ## If xpg_echo is set, use `echo -E` or `printf $'%s\n'` instead
done
return $r;
}
Note: This function does not handle paths starting with //, as exactly two double slashes at the start of a path are implementation-defined behavior. However, it handles /, ///, and so on just fine.
This function seems to handle all edge cases properly, but there might still be some out there that I haven't dealt with.
Performance Note: when called with thousands of arguments, abspath runs about 10x slower than realpath -sm; when called with a single argument, abspath runs >110x faster than realpath -sm on my machine, mostly due to not needing to execute a new program every time.
readlink is the bash standard for obtaining the absolute path. It also has the advantage of returning empty strings if paths or a path doesn't exist (given the flags to do so).
To get the absolute path to a directory that may or may not exist, but who's parents do exist, use:
abspath=$(readlink -f $path)
To get the absolute path to a directory that must exist along with all parents:
abspath=$(readlink -e $path)
To canonicalise the given path and follow symlinks if they happen to exist, but otherwise ignore missing directories and just return the path anyway, it's:
abspath=$(readlink -m $path)
The only downside is that readlink will follow links. If you do not want to follow links, you can use this alternative convention:
abspath=$(cd ${path%/*} && echo $PWD/${path##*/})
That will chdir to the directory part of $path and print the current directory along with the file part of $path. If it fails to chdir, you get an empty string and an error on stderr.
I don't know if there is a direct bash command to do this, but I usually do
normalDir="`cd "${dirToNormalize}";pwd`"
echo "${normalDir}"
and it works well.
I needed a solution that would do all three:
realpath and readlink -f are addonsNone of the answers had both #1 and #2. I added #3 to save others any further yak-shaving.
#!/bin/bash
P="${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 "$P")"
Here is a short test case with some twisted spaces in the paths to fully exercise the quoting
mkdir -p "/tmp/test/ first path "
mkdir -p "/tmp/test/ second path "
echo "hello" > "/tmp/test/ first path / red .txt "
ln -s "/tmp/test/ first path / red .txt " "/tmp/test/ second path / green .txt "
cd "/tmp/test/ second path "
fullpath " green .txt "
cat " green .txt "
As Adam Liss noted realpath is not bundled with every distribution. Which is a shame, because it is the best solution. The provided source code is great, and I will probably start using it now. Here is what I have been using until now, which I share here just for completeness:
get_abs_path() {
local PARENT_DIR=$(dirname "$1")
cd "$PARENT_DIR"
local ABS_PATH="$(pwd)"/"$(basename "$1")"
cd - >/dev/null
echo "$ABS_PATH"
}
If you want it to resolve symlinks, just replace pwd with pwd -P.
Try our new Bash library product realpath-lib that we have placed on GitHub for free and unencumbered use. It's thoroughly documented and makes a great learning tool.
It resolves local, relative and absolute paths and doesn't have any dependencies except Bash 4+; so it should work just about anywhere. It's free, clean, simple and instructive.
You can do:
get_realpath <absolute|relative|symlink|local file path>
This function is the core of the library:
function get_realpath() {
if [[ -f "$1" ]]
then
# file *must* exist
if cd "$(echo "${1%/*}")" &>/dev/null
then
# file *may* not be local
# exception is ./file.ext
# try 'cd .; cd -;' *works!*
local tmppwd="$PWD"
cd - &>/dev/null
else
# file *must* be local
local tmppwd="$PWD"
fi
else
# file *cannot* exist
return 1 # failure
fi
# reassemble realpath
echo "$tmppwd"/"${1##*/}"
return 0 # success
}
It also contains functions to get_dirname, get_filename, get_ stemname and validate_path. Try it across platforms, and help to improve it.
A portable and reliable solution is to use python, which is preinstalled pretty much everywhere (including Darwin). You have two options:
abspath returns an absolute path but does not resolve symlinks:
python -c "import os,sys; print(os.path.abspath(sys.argv[1]))" path/to/file
realpath returns an absolute path and in doing so resolves symlinks, generating a canonical path:
python -c "import os,sys; print(os.path.realpath(sys.argv[1]))" path/to/file
In each case, path/to/file can be either a relative or absolute path.
Based on @Andre's answer, I might have a slightly better version, in case someone is after a loop-free, completely string-manipulation based solution. It is also useful for those who don't want to dereference any symlinks, which is the downside of using realpath or readlink -f.
It works on bash versions 3.2.25 and higher.
shopt -s extglob
normalise_path() {
local path="$1"
# get rid of /../ example: /one/../two to /two
path="${path//\/*([!\/])\/\.\./}"
# get rid of /./ and //* example: /one/.///two to /one/two
path="${path//@(\/\.\/|\/+(\/))//}"
# remove the last '/.'
echo "${path%%/.}"
}
$ normalise_path /home/codemedic/../codemedic////.config
/home/codemedic/.config
I don't know if there is a direct bash command to do this, but I usually do
normalDir="`cd "${dirToNormalize}";pwd`"
echo "${normalDir}"
and it works well.
Use the readlink utility from the coreutils package.
MY_PATH=$(readlink -f "$0")
Talkative, and a bit late answer. I need to write one since I'm stuck on older RHEL4/5. I handles absolute and relative links, and simplifies //, /./ and somedir/../ entries.
test -x /usr/bin/readlink || readlink () {
echo $(/bin/ls -l $1 | /bin/cut -d'>' -f 2)
}
test -x /usr/bin/realpath || realpath () {
local PATH=/bin:/usr/bin
local inputpath=$1
local changemade=1
while [ $changemade -ne 0 ]
do
changemade=0
local realpath=""
local token=
for token in ${inputpath//\// }
do
case $token in
""|".") # noop
;;
"..") # up one directory
changemade=1
realpath=$(dirname $realpath)
;;
*)
if [ -h $realpath/$token ]
then
changemade=1
target=`readlink $realpath/$token`
if [ "${target:0:1}" = '/' ]
then
realpath=$target
else
realpath="$realpath/$target"
fi
else
realpath="$realpath/$token"
fi
;;
esac
done
inputpath=$realpath
done
echo $realpath
}
mkdir -p /tmp/bar
(cd /tmp ; ln -s /tmp/bar foo; ln -s ../.././usr /tmp/bar/link2usr)
echo `realpath /tmp/foo`
A portable and reliable solution is to use python, which is preinstalled pretty much everywhere (including Darwin). You have two options:
abspath returns an absolute path but does not resolve symlinks:
python -c "import os,sys; print(os.path.abspath(sys.argv[1]))" path/to/file
realpath returns an absolute path and in doing so resolves symlinks, generating a canonical path:
python -c "import os,sys; print(os.path.realpath(sys.argv[1]))" path/to/file
In each case, path/to/file can be either a relative or absolute path.
Not exactly an answer but perhaps a follow-up question (original question was not explicit):
readlink is fine if you actually want to follow symlinks. But there is also a use case for merely normalizing ./ and ../ and // sequences, which can be done purely syntactically, without canonicalizing symlinks. readlink is no good for this, and neither is realpath.
for f in $paths; do (cd $f; pwd); done
works for existing paths, but breaks for others.
A sed script would seem to be a good bet, except that you cannot iteratively replace sequences (/foo/bar/baz/../.. -> /foo/bar/.. -> /foo) without using something like Perl, which is not safe to assume on all systems, or using some ugly loop to compare the output of sed to its input.
FWIW, a one-liner using Java (JDK 6+):
jrunscript -e 'for (var i = 0; i < arguments.length; i++) {println(new java.io.File(new java.io.File(arguments[i]).toURI().normalize()))}' $paths
Try our new Bash library product realpath-lib that we have placed on GitHub for free and unencumbered use. It's thoroughly documented and makes a great learning tool.
It resolves local, relative and absolute paths and doesn't have any dependencies except Bash 4+; so it should work just about anywhere. It's free, clean, simple and instructive.
You can do:
get_realpath <absolute|relative|symlink|local file path>
This function is the core of the library:
function get_realpath() {
if [[ -f "$1" ]]
then
# file *must* exist
if cd "$(echo "${1%/*}")" &>/dev/null
then
# file *may* not be local
# exception is ./file.ext
# try 'cd .; cd -;' *works!*
local tmppwd="$PWD"
cd - &>/dev/null
else
# file *must* be local
local tmppwd="$PWD"
fi
else
# file *cannot* exist
return 1 # failure
fi
# reassemble realpath
echo "$tmppwd"/"${1##*/}"
return 0 # success
}
It also contains functions to get_dirname, get_filename, get_ stemname and validate_path. Try it across platforms, and help to improve it.
I discovered today that you can use the stat command to resolve paths.
So for a directory like "~/Documents":
You can run this:
stat -f %N ~/Documents
To get the full path:
/Users/me/Documents
For symlinks, you can use the %Y format option:
stat -f %Y example_symlink
Which might return a result like:
/usr/local/sbin/example_symlink
The formatting options might be different on other versions of *NIX but these worked for me on OSX.
Try realpath. Below is the source in its entirety, hereby donated to the public domain.
// 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);
}
I know this is an ancient question. I'm still offering an alternative. Recently I met the same issue and found no existing and portable command to do that. So I wrote the following shell script which includes a function that can do the trick.
#! /bin/sh
function normalize {
local rc=0
local ret
if [ $# -gt 0 ] ; then
# invalid
if [ "x`echo $1 | grep -E '^/\.\.'`" != "x" ] ; then
echo $1
return -1
fi
# convert to absolute path
if [ "x`echo $1 | grep -E '^\/'`" == "x" ] ; then
normalize "`pwd`/$1"
return $?
fi
ret=`echo $1 | sed 's;/\.\($\|/\);/;g' | sed 's;/[^/]*[^/.]\+[^/]*/\.\.\($\|/\);/;g'`
else
read line
normalize "$line"
return $?
fi
if [ "x`echo $ret | grep -E '/\.\.?(/|$)'`" != "x" ] ; then
ret=`normalize "$ret"`
rc=$?
fi
echo "$ret"
return $rc
}
https://gist.github.com/bestofsong/8830bdf3e5eb9461d27313c3c282868c
Based on @Andre's answer, I might have a slightly better version, in case someone is after a loop-free, completely string-manipulation based solution. It is also useful for those who don't want to dereference any symlinks, which is the downside of using realpath or readlink -f.
It works on bash versions 3.2.25 and higher.
shopt -s extglob
normalise_path() {
local path="$1"
# get rid of /../ example: /one/../two to /two
path="${path//\/*([!\/])\/\.\./}"
# get rid of /./ and //* example: /one/.///two to /one/two
path="${path//@(\/\.\/|\/+(\/))//}"
# remove the last '/.'
echo "${path%%/.}"
}
$ normalise_path /home/codemedic/../codemedic////.config
/home/codemedic/.config
Old question, but there is much simpler way if you are dealing with full path names at the shell level:
abspath="$( cd "$path" && pwd )"
As the cd happens in a subshell it does not impact the main script.
Two variations, supposing your shell built-in commands accept -L and -P, are:
abspath="$( cd -P "$path" && pwd -P )" #physical path with resolved symlinks abspath="$( cd -L "$path" && pwd -L )" #logical path preserving symlinks
Personally, I rarely need this later approach unless I'm fascinated with symbolic links for some reason.
FYI: variation on obtaining the starting directory of a script which works even if the script changes it's current directory later on.
name0="$(basename "$0")"; #base name of script dir0="$( cd "$( dirname "$0" )" && pwd )"; #absolute starting dir
The use of CD assures you always have the absolute directory, even if the script is run by commands such as ./script.sh which, without the cd/pwd, often gives just .. Useless if the script does a cd later on.
I'm late to the party, but this is the solution I've crafted after reading a bunch of threads like this:
resolve_dir() {
(builtin cd `dirname "${1/#~/$HOME}"`'/'`basename "${1/#~/$HOME}"` 2>/dev/null; if [ $? -eq 0 ]; then pwd; fi)
}
This will resolve the absolute path of $1, play nice with ~, keep symlinks in the path where they are, and it won't mess with your directory stack. It returns the full path or nothing if it doesn't exist. It expects $1 to be a directory and will probably fail if it's not, but that's an easy check to do yourself.
Source: Stackoverflow.com