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



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

NAME
       eval - construct command by concatenating arguments

SYNOPSIS
       eval [argument ...]

DESCRIPTION
       The  eval utility shall construct a command by concatenating arguments together, separating each with a <space>. The con-
       structed command shall be read and executed by the shell.

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
       If there are no arguments, or only null arguments, eval shall return a zero exit status; otherwise, it shall  return  the
       exit status of the command defined by the string of concatenated arguments separated by <space>s.

CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.

APPLICATION USAGE
       None.

EXAMPLES
              foo=10 x=foo
              y='$'$x
              echo $y
              $foo
              eval y='$'$x
              echo $y
              10

RATIONALE
       None.

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,  Copy-
       right (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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                      EVAL(1P)