NAME

break - exit from for, while, or until loop

SYNOPSIS

break [n]

DESCRIPTION

The break utility shall exit from the smallest enclosing for, while, or until loop, if any; or from the nth enclosing loop if n is specified. The value of n is an unsigned decimal integer greater than or equal to 1. The default shall be equivalent to n=1. If n is greater than the number of enclosing loops, the outermost enclosing loop shall be exited. Execution shall continue with the command immediately following the loop.

OPTIONS

None.

OPERANDS

See the DESCRIPTION.

STDIN

Not used.

INPUT FILES

None.

ENVIRONMENT VARIABLES

None.

ASYNCHRONOUS EVENTS

Default.

STDOUT

Not used.

STDERR

The standard error shall be used only for diagnostic messages.

OUTPUT FILES

None.

EXTENDED DESCRIPTION

None.

EXIT STATUS

 0

Successful completion.

>0

The n value was not an unsigned decimal integer greater than or equal to 1.

CONSEQUENCES OF ERRORS

Default.

APPLICATION USAGE

None.

EXAMPLES

for i in * do
    if test -d "$i" then break fi done

RATIONALE

In early proposals, consideration was given to expanding the syntax of break and continue to refer to a label associated with the appropriate loop as a preferable alternative to the n method. However, this volume of IEEE Std 1003.1-2001 does reserve the name space of command names ending with a colon. It is anticipated that a future implementation could take advantage of this and provide something like:

outofloop: for i in a b c d e
do
    for j in 0 1 2 3 4 5 6 7 8 9
    do
        if test -r "${i}${j}"
        then break outofloop
        fi
    done
done

and that this might be standardized after implementation experience is achieved.

FUTURE DIRECTIONS

None.

SEE ALSO

Special Built-In Utilities

CHANGE HISTORY

Issue 6

IEEE Std 1003.1-2001/Cor 1-2002, item XCU/TC1/D6/5 is applied so that the reference page sections use terms as described in the Utility Description Defaults ( Utility Description Defaults ). No change in behavior is intended.