File Name of Bash Script

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Fish Shell is preferred to Bash/Zsh. The following content is for Bash/Zsh only.

Do NOT get into this messy shit if you can avoid it! Use Python script instead if you can.
If you want to reliably get the name of a Bash script, it is recommended that you run the Bash script as an executable script instead of source it in.
There are 2 ways ($0 and ${BASH_SOURCE[0]}) to get the file name of a Bash script. ${BASH_SOURCE[0]} is a more robust way and is preferred.

Get File Name Without Parent Directory¶

https://stackoverflow.com/questions/3362920/get-just-the-filename-from-a-path-in-a-bash-script/3362952

!basename /scripts/sys/etc.sh

etc.sh

Get File Name and Extensions¶

%%bash

FILE="example.tar.gz"
echo "${FILE%%.*}"

echo "${FILE%.*}"

echo "${FILE#*.}"

echo "${FILE##*.}"

example
example.tar
tar.gz
gz

`$0` vs `${BASH_SOURCE[0]}`¶

The example below shows that ${BASH_SOURCE[0]} is more robust than $0 and is preferred.

# print the content of a Bash script a.sh
!cat bash-file-name/a.sh | highlight -O ansi

#!/bin/bash

echo '$0: '$0
echo '$(readlink -f $0): '$(readlink -f $0)
echo '${BASH_SOURCE[0]}: '${BASH_SOURCE[0]}
echo ' $(readlink -f ${BASH_SOURCE[0]}): '$(readlink -f ${BASH_SOURCE[0]})

Running the Bash script as an executable script.

!bash-file-name/a.sh

$0: bash-file-name/a.sh
$(readlink -f $0): /workspace/blog/misc/content/bash-file-name/a.sh
${BASH_SOURCE[0]}: bash-file-name/a.sh
 $(readlink -f ${BASH_SOURCE[0]}): /workspace/blog/misc/content/bash-file-name/a.sh

Source in the Bash script.

%%bash

source bash-file-name/a.sh

$0: bash
$(readlink -f $0): /workspace/blog/misc/content/bash
${BASH_SOURCE[0]}: bash-file-name/a.sh
 $(readlink -f ${BASH_SOURCE[0]}): /workspace/blog/misc/content/bash-file-name/a.sh

On Symbolic Links¶

Both $0 and ${BASH_SOURCE[0]} work on symbolic links. You can use readlink to get the raw path of the file.

# create a symbolic link to a.sh as b.sh
!ln -svf $(realpath bash-file-name/a.sh) bash-file-name/b.sh

'bash-file-name/b.sh' -> '/workspace/blog/misc/content/bash-file-name/a.sh'

!bash-file-name/b.sh

$0: bash-file-name/b.sh
$(readlink -f $0): /workspace/blog/misc/content/bash-file-name/a.sh
${BASH_SOURCE[0]}: bash-file-name/b.sh
 $(readlink -f ${BASH_SOURCE[0]}): /workspace/blog/misc/content/bash-file-name/a.sh

%%bash

source bash-file-name/b.sh

$0: bash
$(readlink -f $0): /workspace/blog/misc/content/bash
${BASH_SOURCE[0]}: bash-file-name/b.sh
 $(readlink -f ${BASH_SOURCE[0]}): /workspace/blog/misc/content/bash-file-name/a.sh

Running from Another Script¶

# c.sh runs a.sh
!cat bash-file-name/c.sh | highlight -O ansi

#!/bin/bash

source bash-file-name/a.sh
bash-file-name/a.sh
echo ${BASH_SOURCE[0]}

!bash-file-name/c.sh

$0: bash-file-name/c.sh
$(readlink -f $0): /workspace/blog/misc/content/bash-file-name/c.sh
${BASH_SOURCE[0]}: bash-file-name/a.sh
 $(readlink -f ${BASH_SOURCE[0]}): /workspace/blog/misc/content/bash-file-name/a.sh
$0: bash-file-name/a.sh
$(readlink -f $0): /workspace/blog/misc/content/bash-file-name/a.sh
${BASH_SOURCE[0]}: bash-file-name/a.sh
 $(readlink -f ${BASH_SOURCE[0]}): /workspace/blog/misc/content/bash-file-name/a.sh
bash-file-name/c.sh

%%bash

bash-file-name/c.sh

$0: bash-file-name/c.sh
$(readlink -f $0): /workspace/blog/misc/content/bash-file-name/c.sh
${BASH_SOURCE[0]}: bash-file-name/a.sh
 $(readlink -f ${BASH_SOURCE[0]}): /workspace/blog/misc/content/bash-file-name/a.sh
$0: bash-file-name/a.sh
$(readlink -f $0): /workspace/blog/misc/content/bash-file-name/a.sh
${BASH_SOURCE[0]}: bash-file-name/a.sh
 $(readlink -f ${BASH_SOURCE[0]}): /workspace/blog/misc/content/bash-file-name/a.sh
bash-file-name/c.sh