Bang prefixing to reverse default actions
Some builtins support a bang prefix, !
, which provides a shorthand negative
action to default behavior. For example, set
defines a variable where as
!set
will undefine a variable.
Sometimes the shortcut will be logical, like a not operator, as is the case
with and
where typically each result has to equal true normally or
false if used in !and
.
Sometimes the shortcut will be more philosophical, such as with config
where
normal operations is to query or set configuration but !config
resets the
configuration to defaults (thus operating the same as config default
).
Please read the respecting commands doc for details on whether it supports a bang prefix and what the behavior of that prefix is.
- Define Variable (
set
): Define a variable (typically local) and set it's value - Logic And Statements (
and
): Returnstrue
orfalse
depending on whether multiple conditions are met - Logic Or Statements (
or
): Returnstrue
orfalse
depending on whether one code-block out of multiple ones supplied is successful or unsuccessful. - Not (
!
): Reads the stdin and exit number from previous process and not's it's condition - Pipeline: Overview of what a "pipeline" is
- Reserved Variables: Special variables reserved by Murex
- Shell Configuration And Settings (
config
): Query or define Murex runtime settings
This document was generated from gen/user-guide/bang-prefix_doc.yaml.