BREAK(P) POSIX Programmer s Manual BREAK(P)

PROLOG This manual page is part of the POSIX Programmer s Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

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.

The following sections are informative.

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

COPYRIGHT Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group 2003 BREAK(P)