在所有情况下获取脚本或源脚本的“真实路径”:

fullname=$(readlink $0)  # Take care of  symbolic links
dirname=${fullname%/*}       # Get (most of the time) the dirname
realpath=$(dirname $BASH_SOURCE) # TO handle sourced scripts
[ "$realpath" = '.' ] && realpath=${dirname:-.}

下面是要生成的bash脚本(在新创建的“workdir”子目录中，在当前目录的“mytest”中)，该bash脚本将派生另一个脚本，该脚本将调用bash定义的函数....测试了许多方法来启动它们:

#!/bin/bash
##############################################################

ret=0

fullname=$(readlink $0)  # Take care of  symbolic links
dirname=${fullname%/*}       # Get (most of the time) the dirname
realpath=$(dirname $BASH_SOURCE) # TO handle sourced scripts
[ "$realpath" = '.' ] && realpath=${dirname:-.}

fullname_withoutextension=${fullname%.*}

mkdir -p workdir
cat <<'EOD' > workdir/_script_.sh
#!/bin/bash
##############################################################

ret=0

fullname=$(readlink $0)  # Take care of  symbolic links
dirname=${fullname%/*}       # Get (most of the time) the dirname
realpath=$(dirname $BASH_SOURCE) # TO handle sourced scripts
[ "$realpath" = '.' ] && realpath=${dirname:-.}

fullname_withoutextension=${fullname%.*}

echo
echo "# ------------- RESULTS ------------- #"
echo "# path to me (\$0)----------->  ${0}     "
echo "# arguments called with ---->  ${@}     "
echo "# \$1 ----------------------->  $1       "
echo "# \$2 ----------------------->  $2       "
echo "# path to me (\$fullname)---->  ${fullname} "
echo "# parent path(\${0%/*})------>  ${0%/*}  "
echo "# parent path(\$dirname)----->  ${dirname} "
echo "# my name ----\${0##*/}------>  ${0##*/} "
echo "# my source -\${BASH_SOURCE}->  ${BASH_SOURCE} "
echo "# parent path(from BASH_SOURCE) -> $(dirname $BASH_SOURCE)"
echo "# my function name -\${FUNCNAME[0]}------>  ${FUNCNAME[0]}"
echo "# my source or script real path (realpath)------------------>  $realpath"
echo
[ "$realpath" = "workdir" ] || ret=1
[ $ret = 0 ] || echo "*******************************************************"
[ $ret = 0 ] || echo "***********   ERROR  **********************************"
[ $ret = 0 ] || echo "*******************************************************"

show_params () {
        echo
        echo "# --- RESULTS FROM show_params() ---- #"
        echo "# path to me (\$0)----------->  ${0}     "
        echo "# arguments called with ---->  ${@}     "
        echo "# \$1 ----------------------->  $1       "
        echo "# \$2 ----------------------->  $2       "
        echo "# path to me (\$fullname)---->  ${fullname} "
        echo "# parent path(\${0%/*})------>  ${0%/*}  "
        echo "# parent path(\$dirname)----->  ${dirname} "
        echo "# my name ----\${0##*/}------>  ${0##*/} "
        echo "# my source -\${BASH_SOURCE}->  ${BASH_SOURCE} "
        echo "# parent path(from BASH_SOURCE) -> $(dirname $BASH_SOURCE)"
        echo "# my function name -\${FUNCNAME[0]}------>  ${FUNCNAME[0]}"
        echo "# my source or script real path (realpath)------------------>  $realpath"
        echo
        [ "$realpath" = "workdir" ] || ret=1
        [ $ret = 0 ] || echo "*******************************************************"
        [ $ret = 0 ] || echo "***********   ERROR  **********************************"
        [ $ret = 0 ] || echo "*******************************************************"

}
show_params "$@"

EOD

cat workdir/_script_.sh > workdir/_side_by_side_script_sourced.inc

cat <<'EOD' >> workdir/_script_.sh

echo "# . $realpath/_side_by_side_script_sourced.inc 'hello there' 'william'"
. $realpath/_side_by_side_script_sourced.inc 'hello there' 'william'

[ $ret = 0 ] || echo "*******************************************************"
[ $ret = 0 ] || echo "***********   ERROR  **********************************"
[ $ret = 0 ] || echo "*******************************************************"
EOD

chmod +x  workdir/_script_.sh
[ -L _mytest_ ] && rm _mytest_
ln -s workdir/_script_.sh _mytest_

# ------------- CALLED ------------- #

called_by () {
        echo '=========================================================================='
        echo " Called by : " "$@"
        echo '=========================================================================='
        eval "$@"
}

called_by bash _mytest_
called_by ./_mytest_

called_by bash workdir/_script_.sh
called_by workdir/_script_.sh
called_by . workdir/_script_.sh


# ------------- RESULTS ------------- #

echo
echo
[ $ret = 0 ] || echo "*******************************************************"
[ $ret = 0 ] || echo "***********   ERROR  **********************************"
[ $ret = 0 ] || echo "*******************************************************"
echo
[ $ret = 0 ] && echo ".... location of scripts (\$realpath) should always be equal to $realpath, for all test cases at date".
echo

# ------------- END ------------- #

me=`basename "$0"`

对于读取symlink1，这通常不是你想要的(你通常不想以这种方式迷惑用户)，尝试:

me="$(basename "$(test -L "$0" && readlink "$0" || echo "$0")")"

在我看来，这会产生令人困惑的输出。“我跑了foo.sh，但它说我跑了bar.sh!?”一定是虫子!”此外，使用不同名称的符号链接的目的之一是根据其名称提供不同的功能(例如某些平台上的gzip和gunzip)。

1也就是说，为了解析符号链接，当用户执行foo.sh时，它实际上是一个到bar.sh的符号链接，你希望使用解析的名称bar.sh而不是foo.sh。

使用bash >= 3，以下工作:

$ ./s
0 is: ./s
BASH_SOURCE is: ./s
$ . ./s
0 is: bash
BASH_SOURCE is: ./s

$ cat s
#!/bin/bash

printf '$0 is: %s\n$BASH_SOURCE is: %s\n' "$0" "$BASH_SOURCE"

# ------------- SCRIPT ------------- #

#!/bin/bash

echo
echo "# arguments called with ---->  ${@}     "
echo "# \$1 ---------------------->  $1       "
echo "# \$2 ---------------------->  $2       "
echo "# path to me --------------->  ${0}     "
echo "# parent path -------------->  ${0%/*}  "
echo "# my name ------------------>  ${0##*/} "
echo
exit

# ------------- CALLED ------------- #

# Notice on the next line, the first argument is called within double, 
# and single quotes, since it contains two words

$  /misc/shell_scripts/check_root/show_parms.sh "'hello there'" "'william'"

# ------------- RESULTS ------------- #

# arguments called with --->  'hello there' 'william'
# $1 ---------------------->  'hello there'
# $2 ---------------------->  'william'
# path to me -------------->  /misc/shell_scripts/check_root/show_parms.sh
# parent path ------------->  /misc/shell_scripts/check_root
# my name ----------------->  show_parms.sh

# ------------- END ------------- #

我发现这一行总是有效的，无论文件是源文件还是作为脚本运行。

echo "${BASH_SOURCE[${#BASH_SOURCE[@]} - 1]}"

如果你想遵循符号链接，在上面得到的路径上使用readlink，递归或非递归。

单行程序工作的原因可以通过使用BASH_SOURCE环境变量及其关联的FUNCNAME来解释。

BASH_SOURCE An array variable whose members are the source filenames where the corresponding shell function names in the FUNCNAME array variable are defined. The shell function ${FUNCNAME[$i]} is defined in the file ${BASH_SOURCE[$i]} and called from ${BASH_SOURCE[$i+1]}. FUNCNAME An array variable containing the names of all shell functions currently in the execution call stack. The element with index 0 is the name of any currently-executing shell function. The bottom-most element (the one with the highest index) is "main". This variable exists only when a shell function is executing. Assignments to FUNCNAME have no effect and return an error status. If FUNCNAME is unset, it loses its special properties, even if it is subsequently reset. This variable can be used with BASH_LINENO and BASH_SOURCE. Each element of FUNCNAME has corresponding elements in BASH_LINENO and BASH_SOURCE to describe the call stack. For instance, ${FUNCNAME[$i]} was called from the file ${BASH_SOURCE[$i+1]} at line number ${BASH_LINENO[$i]}. The caller builtin displays the current call stack using this information.

[来源:Bash手册]

以下是我从Dimitre Radoulov的回答中得到的灵感(顺便说一下，我给他的回答投了赞)。

script="$BASH_SOURCE"
[ -z "$BASH_SOURCE" ] && script="$0"

echo "Called $script with $# argument(s)"

不管你如何调用你的脚本

. path/to/script.sh

or

./path/to/script.sh