basename

Bash get script file name and location 1

 in Bash  tagged basename / bash / dirname / pwd / readlink / test -L by

The following code will populate the variables SCRIPT_NAME and SCRIPT_DIR with the name of the script currently being execute and the location this script is in:

SCRIPT_NAME=$(basename $(test -L "$0" && readlink "$0" || echo "$0"));
SCRIPT_DIR=$(cd $(dirname "$0") && pwd);

Notes for SCRIPT_NAME:

  • $0 expands to the name of the shell or shell script
  • test -L "$0" checks that input is a file that exists and is a symbolic link
  • && readlink "$0" will be executed if the above statement is true and it will print the resolved symbolic link
  • || echo "$0" will be executed if the test for symbolic link fails
  • finally, basename will strip directory and suffix from whatever is returned from the above statements

Notes for SCRIPT_DIR:

  • Will not resolve the correct folder if the last component of the path is a symbolic link (symlink). It will return the location of the symlink instead of the location of the file the symlink is pointing to
  • cd will return 0 if it successfully navigates to a directory or 1 when it fails to navigate to the directory
  • cd "$( dirname "$0" )" will use dirname to strip the last component from the expanded name and try to navigate to that location
  • if the above cd fails, we get the current location using && pwd. pwd will print name of current/working directory

In case you have a problem with $0, it is overwritten or the above function is called by a child script in another folder you can replace $0 with ${BASH_SOURCE[0]}.

SCRIPT_NAME=$(basename $(test -L "${BASH_SOURCE[0]}" && readlink "${BASH_SOURCE[0]}" || echo "${BASH_SOURCE[0]}"));
SCRIPT_DIR=$(cd $(dirname "${BASH_SOURCE[0]}") && pwd);

Extract filename from full path filename / Get file extension

 in Bash / GNU/Linux / HowTos  tagged basename / extension / filename / path by

The first command strips down the full path filename to the filename only ising the basename command.

filename=$(basename $filenamefullpath)

Afterwards you can see how to extract the file extension from the filename.  There is no need to do this after issuing the above command since this command will just remove everything after the first from right dot (‘.’) — so make sure that the filename you are parsing has a dot or you will end up with wrong results (like the full path or a part of the full path if it contains a dot somewhere).

extension=${filename##*.}

Finally, by issuing the following command you remove everything after the first dot on the right (including).

filename=${filename%.*}