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eval(1) [linux man page]

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

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 Technol- ogy -- 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 EVAL(P)

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EXIT(P) 						     POSIX Programmer's Manual							   EXIT(P)

NAME
exit - cause the shell to exit SYNOPSIS
exit [n] DESCRIPTION
The exit utility shall cause the shell to exit with the exit status specified by the unsigned decimal integer n. If n is specified, but its value is not between 0 and 255 inclusively, the exit status is undefined. A trap on EXIT shall be executed before the shell terminates, except when the exit utility is invoked in that trap itself, in which case the shell shall exit immediately. 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
The exit status shall be n, if specified. Otherwise, the value shall be the exit value of the last command executed, or zero if no command was executed. When exit is executed in a trap action, the last command is considered to be the command that executed immediately preceding the trap action. CONSEQUENCES OF ERRORS
Default. The following sections are informative. APPLICATION USAGE
None. EXAMPLES
Exit with a true value: exit 0 Exit with a false value: exit 1 RATIONALE
As explained in other sections, certain exit status values have been reserved for special uses and should be used by applications only for those purposes: 126 A file to be executed was found, but it was not an executable utility. 127 A utility to be executed was not found. >128 A command was interrupted by a signal. 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 Technol- ogy -- 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 EXIT(P)

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