The code in miku's answer has absolutely nothing to do with the bash builtintrue, nor/bin/true, nor any other flavor of thetruecommand. In this case,trueis nothing more than a simple character string, and no call to thetruecommand/builtin is ever made, neither by the variable assignment...
unset name:取消已定义变量的属性和值,只读变量除外。 Unset values and attributes of shell variables and functions. 使用示例 #!/bin/bash echo "Set a custom function - func1" echo func1 () { echo This is a function. } echo "Lists the function body." echo "===" declare -f echo echo ...
linuxconfig.org/how-to-use-arrays-in-bash-script I think these are the most common cases when you declare variables. Please notice also, that in a function,declaremakes the variable local (in the function) without any name, it lists all variables (in the active shell) declare Finally, you...
Bash variables can have more than one value. To assign multiple values to a single bash variable, convert it to an array by typing: declare -a testvarCopy If the variable had a value before conversion, that value is now the first element of the array, with the index number0. To check...
+r option does not work; that is stripping a variabl of its readonly attribute is not allowed in bash -a make NAME indexed array -A make NAME associative array -g create global variables when used in a shell function, When used in function "declare" makes NAME local, as with th "loc...
Learn the syntax and use of the Bash declare statement with examples. Master variable declaration and attributes in Bash scripting.
In the normal case, when you write a shell script that only has one or two functions in it, and there's no shadowing of global variables with local variables by the same name, everything works as you expect. I'll let you and Chet hammer out what to do in the more complex cases....
The > intent is that functions be able to declare global variables with > attributes if they desire. It doesn't change the scoping rules or > variable resolution behavior. > > A global var can always be declared out of a func (usually at the beginning of the script) so what's the ...
declare -x PROFILE_ONLY_VARIABLES="ARCH ELIBC IUSE_IMPLICIT KERNEL USE_EXPAND_IMPLICIT USE_EXPAND_UNPREFIXED USE_EXPAND_VALUES_ARCH USE_EXPAND_VALUES_ELIBC USE_EXPAND_VALUES_KERNEL" declare -- PROPERTIES="" declare -x PYTHONDONTWRITEBYTECODE="1" declare -x PYTHON_SINGLE_TARGET="" ...
Oil does not print the definition of variables for declare -p. The script ble.sh uses declare -p to save states of scalar variables and arrays (saved=$(declare -p foo bar)) which will be later used to restore the states by eval (eval -- ...