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 constructed 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
$fooeval y=’$’$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, 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 .