break(1p) — Linux manual page

BREAK(1P)                 POSIX Programmer's Manual                BREAK(1P)

PROLOG top

       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 top

       break — exit from for, while, or until loop

SYNOPSIS top

       break [n]

DESCRIPTION top

       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 top

       None.

OPERANDS top

       See the DESCRIPTION.

STDIN top

       Not used.

INPUT FILES top

       None.

ENVIRONMENT VARIABLES top

       None.

ASYNCHRONOUS EVENTS top

       Default.

STDOUT top

       Not used.

STDERR top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES top

       None.

EXTENDED DESCRIPTION top

       None.

EXIT STATUS top

        0    Successful completion.

       >0    The n value was not an unsigned decimal integer greater than or
             equal to 1.

CONSEQUENCES OF ERRORS top

       Default.

       The following sections are informative.

APPLICATION USAGE top

       None.

EXAMPLES top

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

RATIONALE top

       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 POSIX.1‐2008 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 top

       None.

SEE ALSO top

       Section 2.14, Special Built-In Utilities

COPYRIGHT top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                           BREAK(1P)