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avoiding typo confusion
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Jeff Schaller ♦
Jeff Schaller ♦
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I know that in Bash you can use the syntax

editor = $editor=${new_editor:-/usr/bin/vi}

which will set editor to new_editor if the variable new_editor is not empty and to /usr/bin/vi otherwise. Is it possible to produce similar one-liner, which will set editor to output of some command and to some default value if the output is empty? Something like (only as example, this does not work)

editor=$( $(which emacs) :-/usr/bin/vi )

I know how to do it in several lines of code, but would like to know if an elegant solution exists.

I know that in Bash you can use the syntax

editor = ${new_editor:-/usr/bin/vi}

which will set editor to new_editor if the variable new_editor is not empty and to /usr/bin/vi otherwise. Is it possible to produce similar one-liner, which will set editor to output of some command and to some default value if the output is empty? Something like (only as example, this does not work)

editor=$( $(which emacs) :-/usr/bin/vi )

I know how to do it in several lines of code, but would like to know if an elegant solution exists.

I know that in Bash you can use the syntax

editor=${new_editor:-/usr/bin/vi}

which will set editor to new_editor if the variable new_editor is not empty and to /usr/bin/vi otherwise. Is it possible to produce similar one-liner, which will set editor to output of some command and to some default value if the output is empty? Something like (only as example, this does not work)

editor=$( $(which emacs) :-/usr/bin/vi )

I know how to do it in several lines of code, but would like to know if an elegant solution exists.

edited body
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anon
anon

I know that in Bash you can use the syntax

editor = ${new_editor:-/usr/bin/vi}

which will set editor to new_editor if the variable new_editor is not empty and to /usr/bin/vi otherwise. Is it possible to produce similar one-liner, which will set editor to output of some command and to some default value if the output is empty? Something like (only as example, this does not work)

editor=$( $(which emacs) :-/usr/bin/vi )

I know how to do it in several lines of code, but would like to know if an elegangelegant solution exists.

I know that in Bash you can use the syntax

editor = ${new_editor:-/usr/bin/vi}

which will set editor to new_editor if the variable new_editor is not empty and to /usr/bin/vi otherwise. Is it possible to produce similar one-liner, which will set editor to output of some command and to some default value if the output is empty? Something like (only as example, this does not work)

editor=$( $(which emacs) :-/usr/bin/vi )

I know how to do it in several lines of code, but would like to know if an elegang solution exists.

I know that in Bash you can use the syntax

editor = ${new_editor:-/usr/bin/vi}

which will set editor to new_editor if the variable new_editor is not empty and to /usr/bin/vi otherwise. Is it possible to produce similar one-liner, which will set editor to output of some command and to some default value if the output is empty? Something like (only as example, this does not work)

editor=$( $(which emacs) :-/usr/bin/vi )

I know how to do it in several lines of code, but would like to know if an elegant solution exists.

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John Smith
John Smith
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bash one-liner: set variable to output of command or to default value if output is empty

I know that in Bash you can use the syntax

editor = ${new_editor:-/usr/bin/vi}

which will set editor to new_editor if the variable new_editor is not empty and to /usr/bin/vi otherwise. Is it possible to produce similar one-liner, which will set editor to output of some command and to some default value if the output is empty? Something like (only as example, this does not work)

editor=$( $(which emacs) :-/usr/bin/vi )

I know how to do it in several lines of code, but would like to know if an elegang solution exists.