How to Write Bash If/Else Statements in One Line

How do you write an if statement in a single line in Unix?
How do you write an if-else condition in shell script?
What is in bash if statement?
How do you write an if-else in one line in Python?
What is && in shell script?
What is $? In bash script?
How do you set a variable in bash?
How do you set a variable in Shell?
How do I run a bash script?
How do I get input in bash?
How do you write else in bash?
How do I see condition in bash?

How do you write an if statement in a single line in Unix?

The if case is also much more readable. – jkt123 May 21 '14 at 23:46.
@user3014282: To elaborate Hauke's answer, [ -e /tmp ] && echo 1 ; false ; || echo 2 will print both 1 and 2 . Recasting the same using if ... then ... else ... fi will print only 1 . So && || is not an exact equivalent of the other. –

How do you write an if-else condition in shell script?

Their description with syntax is as follows:

if statement. This block will process if specified condition is true. ...
if-else statement. ...
if..elif..else..fi statement (Else If ladder) ...
if..then..else..if..then..fi..fi..(Nested if) ...
Syntax: case in Pattern 1) Statement 1;; Pattern n) Statement n;; esac. ...
Example 2:

What is in bash if statement?

In Bash, the if statement is part of the conditional constructs of the programming language. The if in a Bash script is a shell keyword that is used to test conditions based on the exit status of a test command. An exit status of zero, and only zero, is a success, i.e. a condition that is true.

How do you write an if-else in one line in Python?

Python if.. elif..else in one line

First of all condition2 is evaluated, if return True then expr2 is returned.
If condition2 returns False then condition1 is evaluated, if return True then expr1 is returned.
If condition1 also returns False then else is executed and expr is returned.

What is && in shell script?

Logical AND operator(&&):

The second command will only execute if the first command has executed successfully i.e, its exit status is zero. This operator can be used to check if the first command has been successfully executed. This is one of the most used commands in the command line. Syntax: command1 && command2.

What is $? In bash script?

$? -The exit status of the last command executed. $0 -The filename of the current script. $# -The number of arguments supplied to a script. $$ -The process number of the current shell.

How do you set a variable in bash?

To create a variable, you just provide a name and value for it. Your variable names should be descriptive and remind you of the value they hold. A variable name cannot start with a number, nor can it contain spaces. It can, however, start with an underscore.

How do you set a variable in Shell?

Unix / Linux - Using Shell Variables

Defining Variables. Variables are defined as follows − variable_name=variable_value. ...
Accessing Values. To access the value stored in a variable, prefix its name with the dollar sign ($) − ...
Read-only Variables. Shell provides a way to mark variables as read-only by using the read-only command. ...
Unsetting Variables.

How do I run a bash script?

Make a Bash Script Executable

1) Create a new text file with a . sh extension. ...
2) Add #!/bin/bash to the top of it. This is necessary for the “make it executable” part.
3) Add lines that you'd normally type at the command line. ...
4) At the command line, run chmod u+x YourScriptFileName.sh. ...
5) Run it whenever you need!

How do I get input in bash?

Example 1:

#!/bin/bash.
# Read the user input.
echo "Enter the user name: "
read first_name.
echo "The Current User Name is $first_name"
echo.
echo "Enter other users'names: "
read name1 name2 name3.

How do you write else in bash?

Following is the syntax of Else If statement in Bash Shell Scripting.
...
Syntax of Bash Else IF – elif.

<expression>	Similar to Bash If statement, you may provide a single condition or multiple conditions after if keyword.
elif	Else If

How do I see condition in bash?

1. Single-bracket syntax

File-based conditions. Allows different kinds of checks on a file. Example: if [ -L symboliclink ]; then. ...
String-based conditions. Allows checks on a string and comparing of strings. Example one: if [ -z "$emptystring" ]; then. ...
Arithmetic (number-based) conditions. Allows comparing integer numbers.