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What does ampersand mean in Linux?
An ampersand does the same thing as a semicolon or newline in that it indicates the end of a command, but it causes Bash to execute the command asynchronously. That means Bash will run it in the background and run the next command immediately after, without waiting for the former to end.
What does double ampersand do in Linux?
Linux Double Ampersand (&&) The command shell interprets the && as the logical AND. When using this command, the second command will be executed only when the first one has been succcefully executed.
What does the semicolon mean in Linux?
(;)
Linux Semicolon (;) you can put two or more commands on the same line separated by the semicolon. All the arguments before (;) will be treated as a separate command from all the arguments after the (;). All the commands will be executed sequentially waiting for each command to finish before starting the new one.
What does disown do in Linux?
In the Unix shells ksh, bash, fish and zsh, the disown builtin command is used to remove jobs from the job table, or to mark jobs so that a SIGHUP signal is not sent to them if the parent shell receives it (e.g. if the user logs out).
How to use ampersand in a command line?
So, if you had heard the term before and wondered what they were, there you go. As usual, there are more ways to use the ampersand within a command line, many of which have nothing to do with pushing processes into the background.
What does ampersand mean at the end of a shell line?
The functional part of sys-snap.sh (when you look at it’s contents with something like the less command) is the Shebang. On the first line you will probably find one of: or similar. In basic terms, a the command after the #! (such as /bin/sh) is ran and the contents of the rest of the script file is fed to it a line at a time.
Why do I need ampersand and & in Linux?
But if that turns out to be a lot of data, it could tie up your terminal for hours. pushes the process to the background courtesy of the final &. This frees you to continue working on the same terminal or even to close the terminal and still let the process finish up.
Is the name of SYS-snap.sh arbitrary?
As to the name of sys-snap.sh, under unix file names are arbitrary (with a couple of exceptions like dynamic loader files). There is no requirement for them to have specific file extentions to make them run as a shell script, invoke other commands such as perl or php etc.