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How to convert upper case string to lower case in Bash?
What is the Bash command I can use to convert an upper-case string to lower-case and vice-versa? Thank you. If the string is already stored in a variable you can use bash ‘s parameter expansion, specifially $ {parameter,,pattern} (available since bash 4.0), where parameter is the name of your variable and pattern is ommitted:
When to use lower case or upper case?
Lower case should be used for local variables for ease of typing (speed / no shift key). Upper case is used to help readability by separating the words within a name. Code with single-word local variable names (which should be common) are fast and easy to type.
Why do we use lowercase for variable names?
That naming convention is often used when people want to be able to give a variable the same name as its type. For example: Some languages even enforce that capitalization. This prevents having to use annoying variable names like MyEmployee, CurrentEmployee, EmployeeVar, etc.
Why do I need to store my Bash output in variables?
Sorry, there is a loong answer, but as bash is a shell, where the main goal is to run other unix commands and react to resut code and/or output, ( commands are often piped filter, etc… ). Storing command output in variables is something basic and fundamental.
How are variables and command substitution used in Bash?
Bash variables and command substitution Using variables to refer to data, including the results of a command. An essential feature of programming is the ability to use a name or a label to refer to some other quantity: such as a value, or a command. This is commonly referred to as variables.
How to convert a string to a string in Bash?
$ string=”Hello, World!” $ echo $string Hello, World! $ echo $ {string,,} hello, world! Note that this does not change the value of the variable, only the output. To change the variable you have to assign the new value: $ echo $string Hello, World! $ string=$ {string,,} $ echo $string hello, world! $ echo $ {string^^} HELLO, WORLD!
Which is the first character in a string in Bash?
Here, the first character is compared with ‘l’ and ‘h’ by the last two commands. In the following example, $language variable is used to store a text value and the third command is used to covert the first character of each word of the string to uppercase where the first character is ‘p’.