To pass all the arguments on, you have to use $@. If an argument is passed to the function, it is printed as a message. Why would you need that you ask? The function badUsage may or may not make an argument. This is a while loop that uses the getopts function and a so-called optstring—in this case u:d:p:f:—to iterate through the arguments. You can use $1, $2, $3 and so on to access the arguments inside the function. We also have an option to pass input arguments to the bash function. Here, 4 options are used which are ‘i’, ‘n’, ‘m’ and ‘e’ . Arguments could be passed to functions and accessed inside the function as $1, $2 etc. When I do to call the function I just need to pass the values that I want for $1 $2 and so forth. case statement is used … To do the same without quotes, they'd do program -p hello_world -tSu, where the function program itself gets three arguments. – kashyap Apr 24 '17 at 21:57 @kashyap case doesn't loop. Passing Arguments in Bash Functions. You should use getopt or getopts for processing options. badUsage Then there is the function for … (Or if you want to lock yourself to exactly three arguments, $1 to $3.) Create a bash file and add the following script to understand the use of getopts function. Here is an example. 2 - Arguments in bash functions. Put any parameters for a bash function right after the function’s name, separated by whitespace, just like you were invoking any shell script or command. Here’s how to call a function in Bash, with or without arguments. Bash Functions – In this Bash Tutorial, we shall learn about functions in Bash Shell Scripting with the help of syntax and examples.. About Bash Functions. Note: for arguments more than 9 $10 won't work (bash will read it as $10), you need to do ${10}, ${11} and so on. Bash Functions. If you don't modify the argument in any way, there is no need to copy it to a local variable - simply echo "Hello, $1". abc "$@" When using $@, you should (almost) always put it in double-quotes to avoid misparsing of arguments containing spaces or wildcards (see below).This works for multiple arguments. So now about arguments with bash functions. The $@ variable expands to all command-line parameters separated by spaces. Each bash function has its own set of positioned arguments just like that of the main script file. You can pass arguments to the bash function easily by writing them with double quotes after function name separated by space. Passing inputs to a function is no different from passing arguments to a Bash script: function simple_inputs() { echo "This is the first argument [$1]" echo "This is the second argument [$2]" echo "Calling function with $# arguments" } simple_inputs one 'two three' Let’s take a … Function has to be defined in the shell script first, before you can use it. $1 only contains one of them, in both Bash and Zsh. Don’t … ‘getopts’ function is used with while loop to read command line argument options and argument values. Call bash function with arguments. after having the functions above the case it worked, but if I give the two options at a time only the first option is working!!! badUsage "Option/command not recognized." The scope of a local variable limited to function while you can access global variables out of function. It is also portable to all POSIX-compliant shells. 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