I have method that should receive string, but it does not work as intended
receive_string()
{
local string=$1
echo "$string"
}
When I call it I get unrelated error.
receive_string "Catch a string my friend!"
Returns:
4: local: friend!: bad variable name
Instead of
Catch a string my friend!
What is the problem, and how to solve it?
The problem is that variable expansion is literal in bash, so
local string=$1 will behave as local string=Catch a string my friend!.
It is a good practice to enclose between double quotes your string variables, so they don't separate during expansion. Try this:
local string="$1"
It won't add quotes to your string and it will keep it together.
About the ! specific behavior, check KamilCuk's answer.
You are not running your script with bash. You are running your script under dash shell. The behavior does not happen on bash - in bash the command local is very specially handled like ex. export and arguments have same semantics as on assignment. Most probably the shebang of your script is #!/bin/sh and sh is linked to dash on your system. Use shebang with bash to run bash.
local string=$1
is expanding $1 so it becomes:
local string=Catch a string my friend!
which creates a variable string with value Catch, empty variables a string and my and friend! is invalid variable value.
As always, quote variable expansion.
local string="$1"
Research when to quote variables in shell. Check your scripts with http://shellcheck.net
Side note: the ! in "something!" triggers history expansion in bash. In bash when in interactive shell with history expansion enabled, you would put it ex. in single quotes "something"'!'.
