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 semicolon do in shell script?
A semicolon or ampersand ( ; or & ) in a shell script is a command terminator. You can’t use it if it doesn’t follow a command. ; means “run the preceding command in the foreground” and & means “run the preceding command in the background”. A newline in a shell script is a “weak” command terminator.
Is semicolon mandatory in bash script?
The double semicolon is also useful as it leaves no ambiguity in the code. It is required as it is used at the end of each clause as required by the bash syntax in order to parse the command correctly. It is only used in case constructs to indicate that the end of an alternative.
What semicolon means in bash?
When the shell sees a semicolon (;) on a command line, it’s treated as a command separator — basically like pressing the ENTER key to execute a command. You’ll see all of them on the same command line and they’ll be grouped together in the history list (Section 30.7). …
What is the effect of putting a semicolon at the end of a single simple command or a complex command for example will the output of the following commands be different ?$ Who am I who am I?
The Semicolon lets the compiler know that it’s reached the end of a command. Semicolon is often used to delimit one bit of C++ source code, indicating it’s intentionally separated from the respective code.
What is && in bash?
4 Answers. “&&” is used to chain commands together, such that the next command is run if and only if the preceding command exited without errors (or, more accurately, exits with a return code of 0).
Can you use three semicolons in one sentence?
In this context, it’d be ok to use multiple ones in the list but not ok to use them to link sentences (this being the general rule – let me flesh this one out below).
How do bash scripts work?
A Bash script is a plain text file which contains a series of commands. These commands are a mixture of commands we would normally type ouselves on the command line (such as ls or cp for example) and commands we could type on the command line but generally wouldn’t (you’ll discover these over the next few pages).
What is the use of & in Linux?
The & makes the command run in the background. From man bash : If a command is terminated by the control operator &, the shell executes the command in the background in a subshell. The shell does not wait for the command to finish, and the return status is 0.
What are bash commands?
Bash (AKA Bourne Again Shell) is a type of interpreter that processes shell commands. A shell interpreter takes commands in plain text format and calls Operating System services to do something. For example, ls command lists the files and folders in a directory. Bash is the improved version of Sh (Bourne Shell).
What does P mean in bash?
The -p option in bash and ksh is related to security. It is used to prevent the shell reading user-controlled files.