$ string=${string,,} $ string=${string~} $ echo "$string" A few words To turn off adeclareattribute, use+. For example,declare +c string. This affects subsequent assignments and not the current value. Thedeclareoptions change the attribute of the variable, but not the contents. The re...
Use regex on a stringThe result of bash's regex matching can be used to replace sed for a large number of use-cases.CAVEAT: This is one of the few platform dependent bash features. bash will use whatever regex engine is installed on the user's system. Stick to POSIX regex features if...
Change a string to lowercaseCAVEAT: Requires bash 4+Example Function:lower() { # Usage: lower "string" printf '%s\n' "${1,,}" }Example Usage:$ lower "HELLO" hello $ lower "HeLlO" hello $ lower "hello" helloChange a string to uppercaseCAVEAT: Requires bash 4+...
You can change the case of the string very easily by using tr command. To define uppercase, you can use [:upper:] or [A-Z] and to define lowercase you can define [:lower:] or [a-z]. The `tr` command can be used in the following way to convert any string from uppercase to ...
The-rflag makesreadonly_varread-only. Attempting to change it will result in an error. Once set, it cannot be changed. 3.2. Force a Variable to Be an Integer (-i) Bash will treat the variable as a number and do calculations automatically. ...
Note:Although it is possible to use[a-z]to denote a lowercase character range, uppercase characters are trapped as well on someLinux distributions. 3. Save the file and close the text editor. 4. Change permissions to make the script executable: ...
as the ability to clear the screen or scroll backward. The -d option does not otherwise change the behavior of less on a dumb termi‐ nal. -Dxcolor or --color=xcolor [MS-DOS only] Sets the color of the text displayed. x is a single character which selects the type of text whose ...
#Declare a function to return a string value function ret_strdata() { #Initialize the variable with string value return_str="Learn bash programming with LinuxHint" } #Declare a function to read argument value function calculate_area() { #Read the passed argument value local radius=$1 area=...
There is no in array operator in bash to check if an array contains a value. Instead, to check if a bash array contains a value you will need to test the values in the array by using a bash conditional expression with the binary operator =~. The string to the right of the operator...
To test this, attempt to change the variable's value to a string of characters. declare testvar="example"Copy Usethe echo commandto see the value of the variable. echo $testvarCopy The output shows the value of zero (0): The value of a variable can also be the result of a mathemati...