# STDLIB Variable Function Reference ## Index * [stdlib.var.assert.is_empty](#stdlibvarassertis_empty) * [stdlib.var.assert.is_set](#stdlibvarassertis_set) * [stdlib.var.assert.is_valid_name](#stdlibvarassertis_valid_name) * [stdlib.var.assert.is_valid_with](#stdlibvarassertis_valid_with) * [stdlib.var.global.assert.is_valid_with](#stdlibvarglobalassertis_valid_with) * [stdlib.var.query.is_empty](#stdlibvarqueryis_empty) * [stdlib.var.query.is_set](#stdlibvarqueryis_set) * [stdlib.var.query.is_valid_name](#stdlibvarqueryis_valid_name) * [stdlib.var.query.is_valid_with](#stdlibvarqueryis_valid_with) ### stdlib.var.assert.is_empty Asserts that a variable is an empty value (unset variables, empty arrays, empty associative arrays, empty strings and empty integers). #### Arguments * **$1** (string): The name of the variable to check. #### Exit codes * **0**: If the assertion succeeded. * **1**: If the assertion failed. * **126**: If an invalid argument has been provided. * **127**: If the wrong number of arguments were provided. #### Output on stderr * The error message if the assertion fails. ### stdlib.var.assert.is_set Asserts that a variable is set. #### Arguments * **$1** (string): The name of the variable to check. #### Exit codes * **0**: If the assertion succeeded. * **1**: If the assertion failed. * **126**: If an invalid argument has been provided. * **127**: If the wrong number of arguments were provided. #### Output on stderr * The error message if the assertion fails. ### stdlib.var.assert.is_valid_name Asserts that a string is a valid variable name. #### Arguments * **$1** (string): The string to check. #### Exit codes * **0**: If the assertion succeeded. * **1**: If the assertion failed. * **126**: If an invalid argument has been provided. * **127**: If the wrong number of arguments were provided. #### Output on stderr * The error message if the assertion fails. ### stdlib.var.assert.is_valid_with Asserts a variable's value is valid against a validation function. * STDLIB_VALIDATION_SOURCE_VAR string keyword: An optional variable name that can be used as a source for validation (logging will still attribute the value to the argument provided variable name) (default=""). #### Arguments * **$1** (string): The validation function to run. * **$2** (string): The name of the variable containing the value to perform validation on. * **$3** (string): (optional, default="value") Controls whether the 'name' or 'value' of the variable is passed to the validation function. #### Exit codes * **0**: If the assertion succeeded. * **1**: If the assertion failed. * **125**: If an invalid keyword has been provided. * **126**: If an invalid argument has been provided. * **127**: If the wrong number of arguments were provided. #### Output on stderr * The error message if the assertion fails. ### stdlib.var.global.assert.is_valid_with Asserts a global variable's value is valid against a validation function. * STDLIB_VALIDATION_SOURCE_VAR string keyword: An optional variable name that can be used as a source for validation (logging will still attribute the value to the argument provided variable name) (default=""). #### Arguments * **$1** (string): The validation function to run. * **$2** (string): The name of the global variable containing the value to perform validation on. * **$3** (string): (optional, default="value") Controls whether the 'name' or 'value' of the variable is passed to the validation function. #### Exit codes * **0**: If the global variable passes the validation function. * **1**: If the global variable fails the validation check. * **125**: If an invalid keyword has been provided. * **126**: If an invalid argument has been provided. * **127**: If the wrong number of arguments were provided. #### Output on stderr * The error message if the assertion fails. ### stdlib.var.query.is_empty Checks if a variable is an empty value (unset variables, empty arrays, empty associative arrays, empty strings and empty integers). #### Arguments * **$1** (string): The name of the variable to check. #### Exit codes * **0**: If the variable is an empty value. * **1**: If the variable is not an empty value. * **126**: If an invalid argument has been provided. * **127**: If the wrong number of arguments were provided. ### stdlib.var.query.is_set Checks if a variable is set. #### Arguments * **$1** (string): The name of the variable to check. #### Exit codes * **0**: If the variable is set. * **1**: If the variable is not set. * **126**: If an invalid argument has been provided. * **127**: If the wrong number of arguments were provided. ### stdlib.var.query.is_valid_name Checks if a string is a valid variable name. #### Arguments * **$1** (string): The string to check. #### Exit codes * **0**: If the string is a valid variable name. * **1**: If the string is not a valid variable name. * **126**: If an invalid argument has been provided. * **127**: If the wrong number of arguments were provided. ### stdlib.var.query.is_valid_with Checks if a variable's value is valid against a validation function. * STDLIB_VALIDATION_SOURCE_VAR string keyword: An optional variable name that can be used as a source for validation (default=""). #### Arguments * **$1** (string): The validation function to run. * **$2** (string): The name of the variable containing the value to perform validation on. * **$3** (string): (optional, default="value") Controls whether the 'name' or 'value' of the variable is passed to the validation function. #### Exit codes * **0**: If the variable passes the validation function. * **1**: If the variable fails the validation check. * **125**: If an invalid keyword has been provided. * **126**: If an invalid argument has been provided. * **127**: If the wrong number of arguments were provided.