How do I return a value from a shell script?

How do I return a value from a shell script?

A function may return a value in one of four different ways:

1. Change the state of a variable or variables.
2. Use the exit command to end the shell script.
3. Use the return command to end the function, and return the supplied value to the calling section of the shell script.

How do I return in bash?

When a bash function completes, its return value is the status of the last statement executed in the function, 0 for success and non-zero decimal number in the 1 – 255 range for failure. The return status can be specified by using the return keyword, and it is assigned to the variable $? .

What is $_ in shell script?

$_ (dollar underscore) is another special bash parameter and used to reference the absolute file name of the shell or bash script which is being executed as specified in the argument list. This bash parameter is also used to hold the name of mail file while checking emails.

What is return code in shell script?

What is an exit code in the UNIX or Linux shell? An exit code, or sometimes known as a return code, is the code returned to a parent process by an executable. On POSIX systems the standard exit code is 0 for success and any number from 1 to 255 for anything else.

How do you return a string from a function in shell script?

This is a way of returning string value from a bash function.

1. function F1() { retval=’I like programming’ } retval=’I hate programming’
2. function F2() { local retval=’Using BASH Function’ echo “$retval” }
3. function F3() { local arg1=$1. if [[ $arg1 != “” ]]; then.
4. function F4() { echo ‘Bash Return Statement’ return 35. } F4.

What is return in bash?

Function Return A bash function can return a value via its exit status after execution. By default, a function returns the exit code from the last executed command inside the function. It will stop the function execution once it is called. You can use the return builtin command to return an arbitrary number instead.

What does $? Mean?

$? = was last command successful. Answer is 0 which means ‘yes’. https://stackoverflow.com/questions/12741710/what-does-mean-in-a-shell-script/17010905#17010905. answered Jun 9 ’13 at 14:59.

What does $! Mean in bash?

Actually, these variables were inherited by bash from the Bourne shell. $$ means current PID. $! is the PID of the last program your shell ran in the background (e.g. myprog & )

What is exit code in C?

exit() Terminate the program: The exit() function is used to terminate program execution and to return to the operating system. The return code “0” exits a program without any error message, but other codes indicate that the system can handle the error messages.

What is a return code in Linux?

An exit code, or sometimes known as a return code, is the code returned to a parent process by an executable. On POSIX systems the standard exit code is 0 for success and any number from 1 to 255 for anything else. If exit codes are not set the exit code will be the exit code of the last run command.