setsid

setsid is a command in Unix and Unix-like operating systems that runs a program in a new session. The command calls fork() if it is already a process group leader. Otherwise, it executes a program in the current process. This behavior can be overridden using the --fork option

Here is an example of how to use setsid:

setsid [options] program [arguments]

In this command, program is the process you want to run. The [arguments] are optional parameters for the program [^Source 0^].

There are several options you can use with setsid:

• -c, --ctty: Set the controlling terminal to the current one.
• -f, --fork: Always create a new process.
• -w, --wait: Wait for the execution of the program to end, and return the exit status of this program as the exit status of setsid.
• -V, --version: Display version information and exit.
• -h, --help: Display help text and exit [^Source 0^].

Here is an example of using these options:

sudo setsid -c ./add.sh

In this example, the current terminal is set to be the controlling terminal. If the process takes some time to execute, you can use the -w option to wait for it to finish and get the exit value:

setsid -w ./add.sh

Remember that setsid creates a new session if the calling process is not a process group leader. The calling process becomes the leader of the new session and also becomes the process group leader of a new process group in the session [^Source 2^].