What is the exit status of a command substitution?

What is the exit status of a command substitution?

If one of the expansions contained a command substitution, the exit status of the command is the exit status of the last command substitution performed. Quoting from BASHFAQ/002:

What does exit status mean in Linux shell?

Every Linux or Unix command executed by the shell script or user has an exit status. Exit status is an integer number. 0 exit status means the command was successful without any errors. A non-zero (1-255 values) exit status means command was a failure.

How to get the exit code of a command?

You need to use a particular shell variable called $? to get the exit status of the previously executed command. To print $? variable use the echo command or printf command: echo $? printf ‘%dn’ $? From the above outputs, it is clear that the exit code is 0 indicates that date command was successful.

What do the exit codes in Bash mean?

Exit Codes With Special Meanings Exit status Description 1 Catchall for general errors 2 Misuse of shell builtins (according to B 126 Command invoked cannot execute 127 Command not found

What’s the exit code for the assignment to ATO?

# Prints 0 causes the exit code for the assignment to ato be returned which is 0. EDIT: Quoting from the manual: If one of the expansions contained a command substitution, the exit status of the command is the exit status of the last command substitution performed.

How to tell the exit code of a variable?

When you say: a=$(false) # false fails; the output of false is stored in the variable a the output produced by the command falseis stored in the variable a. Moreover, the exit code is the same as produced by the command. help falsewould tell: false: false Return an unsuccessful result. Exit Status: Always fails.

How is the output of a command replaced in Bash?

Upon executing a command as $(command)allows the output of the command to replace itself. When you say: a=$(false) # false fails; the output of false is stored in the variable a the output produced by the command falseis stored in the variable a.