public/subjects/devops/custom-ls

custom-ls

Instructions

Create the script custom-ls.sh which will create an alias custom-ls.

The alias custom-ls:

• shows the file details in long list format.
• does not list group information.
• does not ignore entries starting with ..
• prints the allocated size of each file, in blocks.
• sorts by file size, largest first.

Expected behavior:

$ custom-ls
error: command not found: custom-ls
$ ./custom-ls.sh
$ custom-ls .
total ...
7784 -rw-r--r--  1 <user>  3983261 Dec 17 22:02 .file1 # just an example
3064 -rw-r--r--  1 <user>  1566444 Dec 17 22:12 file2 # just an example
$

Hints

An alias is a shortcut that references a command. An alias replaces a string that invokes a command in the Linux shell with another user-defined string.

alias command instructs the shell to replace one string with another string while executing the commands.

$ alias testcmd="echo 01school"
$ testcmd
01school
$ alias
testcmd='echo 01school'
<...>
$

However, this update alias gets removed after closing the working environment.

To create and add aliases permanently to your bash shell on Linux and Unix-like systems:

1- Edit the ~/.bashrc:

vi ~/.bashrc
# or #
nano ~/.bashrc

2- Append your bash alias, For example append:

alias testcmd="echo 01school"

3- Save and close the file. 4- Activate alias

source ~/.bashrc

unalias unalias removes each alias name from the current shell execution environment.

$ alias
testcmd='echo 01school'
<...>
$ unalias testcmd
$ alias
<...>
$

You have to use Man or Google to know more about commands flags, in order to solve this exercise! Google and Man will be your friends!

References

alias command in linux with examples. man ls.