OR use backticks based syntax as follows to assign output of a Linux or Unix command to a variable: Do not put any spaces after the equals sign and command must be on right side of =. See how to assign values to shell variables for more information.

Some common examples for Linux, macOS, *BSD and Unix-like systems running bash assign command output to a variable. To store date command output to a variable called now, enter: OR To display back result (or output stored in a variable called $now) use the echo command or printf command:

To assign output of any shell command to variable in bash, use the following command substitution syntax: OR use backticks based syntax as follows to assign output of a Linux or Unix command to a variable: Do not put any spaces after the equals sign and command must be on right side of =.

A shell assignment is a single word, with no space after the equal sign. So what you wrote assigns an empty value to thefile; furthermore, since the assignment is grouped with a command, it makes thefile an environment variable and the assignment is local to that particular command, i.e. only the call to ls sees the assigned value.