CODEWITHSUNDEEP
bashshellalias
Em Ae
Em Ae

Reputation: 8704

Create shell alias with value from current path

I want to create a shell alias which would run

command ew --constantswitch --anotherconstantswitch <name>

Now the value name needs to be extracted from the current path. the current path looks like this

[username@path-to-shell-xxxxxxxx]/path/to/directory/with/name%

How can I create an alias such that when I run aliasX it will

  1. Extract the name from current path (which is last value of the prompt)
  2. Add this path to the command above and execute.

Upvotes: 1

Views: 749

Answers (2)

iBug
iBug

Reputation: 37227

An alias may not be competent for the job, but a function surely do. Try this code:

myfunc() {
  command ew --constantswitch --anotherconstantswitch "${PWD##*/}"
}

The trick is ${PWD##*/}. You know the automatic variable $PWD is exactly what you get when you run pwd, as well as Bash's builtin string substitution ${var##pattern} that removes pattern from the left of the variable with maximum match. So ${PWD##*/} removes everything except the name after the last slash, which as you described is what you're looking for.

In practice, a function is more versatile than an alias. If you still need to add extra arguments to the command, append "$@" to the end of the command inside the function, so any argument that you pass to the function will be forwarded to the command.

Upvotes: 7

Benjamin W.
Benjamin W.

Reputation: 52112

Since you're not trying to do anything involving arguments, an alias is actually possible:

alias aliasX='echo "${PWD##*/}"'

This will print the current directory name when you use aliasX. Or, using your example:

alias aliasX='command ew --constantswitch --anotherconstantswitch "${PWD##*/}"'

Notice that the alias must be in single quotes or $PWD will expand when you define it instead of when you use it.

For anything slightly more complex, you should use a function instead of an alias, as shown in iBug's answer.

Upvotes: 2

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