Get list of variables whose name matches a certain pattern

问题

In bash

echo ${!X*}

will print all the names of the variables whose name starts with 'X'.
Is it possible to get the same with an arbitrary pattern, e.g. get all the names of the variables whose name contains an 'X' in any position?

回答1:

Use the builtin command compgen:

compgen -A variable | grep X

回答2:

This should do it:

env | grep ".*X.*"

Edit: sorry, that looks for X in the value too. This version only looks for X in the var name

env | awk -F "=" '{print $1}' | grep ".*X.*"

As Paul points out in the comments, if you're looking for local variables too, env needs to be replaced with set:

set | awk -F "=" '{print $1}' | grep ".*X.*"

回答3:

This will search for X only in variable names and output only matching variable names:

set | grep -oP '^\w*X\w*(?==)'

or for easier editing of searched pattern

set | grep -oP '^\w*(?==)' | grep X

or simply (maybe more easy to remember)

set | cut -d= -f1 | grep X

If you want to match X inside variable names, but output in name=value form, then:

set | grep -P '^\w*X\w*(?==)'

and if you want to match X inside variable names, but output only value, then:

set | grep -P '^\w*X\w*(?==)' | grep -oP '(?<==).*'

回答4:

Easiest might be to do a

printenv |grep D.*=

The only difference is it also prints out the variable's values.

回答5:

env | awk -F= '{if($1 ~ /X/) print $1}'

来源：https://stackoverflow.com/questions/511694/get-list-of-variables-whose-name-matches-a-certain-pattern