Linux / Unix: Shell Script Find Out In Which Directory Script File Resides
I need to find out in which directory my bash script resides so that I can read config file called .backup .ignore .target. For example, if my script resides in >/home/foo/script.sh, I need to read /home/foo/.{backup,ignore,target} files.
How do I find out the current directory location and shell script directory location in Bash running on Linux or Unix like operating systems?
You can use any one of the following method to find out the portion of pathname:
basename command – Display filename portion of pathname.
dirname command – Display directory portion of pathname.
Bash parameter substitution.
$0 expands to the name of the shell or shell script.
Examples: Shell script find out which directory the script file resides
The following example display directory path or portion of /home/nixcraft/scripts/foo.sh:
dirname /home/nixcraft/scripts/foo.sh
Sample outputs:
/home/nixcraft/scripts
The following line sets the shell variable i to /home/nixcraft/scripts:
i=dirname /home/nixcraft/scripts/foo.sh
echo $i
OR
i=$(dirname /home/nixcraft/scripts/foo.sh)
echo $i
In bash script use $0 instead of /home/nixcraft/scripts/foo.sh:
#!/bin/bash
script= $0
basename= $(dirname $script)
echo Script name $script resides in $basename directory.
Sample outputs:
Script name /tmp/test.sh resides in /tmp directory.
Using bash shell ${var%pattern} syntax
To Remove from shortest rear (end) pattern use the following syntax:
var=${path%/*}
For example:
x= /Users/nixcraft/scripts/bar.sh
echo ${x%/*}
y= ${x%/*}
echo $y
An updated version of the above script:
#!/bin/bash
# Purpose : Linux / Unix shell script find out which directory this script file resides
# Author : nixCraft <http://www.cyberciti.biz> under GPL v2.x+
# ————————————————————————————-
script= $0
basename= ${script%/*}
config1= ${basename}/.backup
config2= ${basename}/.ignore
config3= ${basename}/.target
echo Script name $script resides in $basename directory.
echo Reading config file $config1 $config2 $config3, please wait…
Run it as:
$ chmod +x /tmp/test.sh
$ /tmp/test.sh
Sample outputs:
Fig.01 Sample run from test.sh
A note about finding physical or real path
You may not get a real physical path and real path may be a symbolic link. To get physical path use realpath command. The realpath command uses the realpath() function to resolve all symbolic links, extra / characters and references to /./ and /../ in path. This is useful for shell scripting and security related applications.
Another recommended option is to use the readlink command to display value of a symbolic link or canonical file name:
#!/bin/bash
# Purpose : Linux / Unix shell script find out which directory this script file resides
# Author : nixCraft <http://www.cyberciti.biz> under GPL v2.x+
# ————————————————————————————-
Who am i? ##
Get real path ##
_script= $(readlink -f ${BASH_SOURCE[0]})
Delete last component from $_script ##
_mydir= $(dirname $_script)
Delete /path/to/dir/ component from $_script ##
_myfile= $(basename $_script)
echo Script : $_script
echo Directory portion of $_script : $_mydir
echo Filename portion of $_script : $_myfile
Save and close the file. Run it as follows:
./demo.bash
cd /home/vivek/
../../tmp/demo.bash
/tmp/demo.bash
Sample outputs:
Fig.02: Finding real path
See also
See man pages for more info – basename(1), dirname(1), bash(1)