set or unset options and positional parameters
|
-e When this option is on, if a simple command fails for any of the reasons listed in Consequences of
Shell Errors or returns an exit status value >0, and is not part of the compound list following a
while, until, or if keyword, and is not a part of an AND or OR list, and is not a pipeline
preceded by the ! reserved word, then the shell shall immediately exit.
|
-u The shell shall write a message to standard error when it tries to expand a variable that is not
set and immediately exit. An interactive shell shall not exit.
|
-x The shell shall write to standard error a trace for each command after it expands the command and
before it executes it. It is unspecified whether the command that turns tracing off is traced.
|
-o Write the current settings of the options to standard output in an unspecified format.
+o Write the current option settings to standard output in a format that is suitable for reinput to
the shell as commands that achieve the same options settings.
|
-f The shell shall disable pathname expansion.
|
-a When this option is on, the export attribute shall be set for each variable to which an assignment
is performed; see the Base Definitions volume of IEEE Std 1003.1-2001, Section 4.21, Variable
Assignment. If the assignment precedes a utility name in a command, the export attribute shall not
persist in the current execution environment after the utility completes, with the exception that
preceding one of the special built-in utilities causes the export attribute to persist after the
built-in has completed. If the assignment does not precede a utility name in the command, or if
the assignment is a result of the operation of the getopts or read utilities, the export attribute
shall persist until the variable is unset.
|