04-27-2010
If there is no command line argument and if STDIN is not redirected (file or pipe), the program should exit and output a usage message. The script is meant to behave like a normal UNIX command line utility. I appreciate you taking the time to help pravin27.
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nohup(1) General Commands Manual nohup(1)
NAME
nohup - run a command immune to hangups
SYNOPSIS
command [arguments]
DESCRIPTION
executes command with hangups and quits ignored. If output is not redirected by the user, both standard output and standard error are sent
to If is not writable in the current directory, output is redirected to otherwise, fails. If a file is created, the file's permission bits
will be set to
If output from is redirected to a terminal, or is not redirected at all, the output is sent to
EXTERNAL INFLUENCES
Environment Variables
determines the language in which messages are displayed.
If is not specified in the environment or is set to the empty string, the value of is used as a default for each unspecified or empty vari-
able. If is not specified or is set to the empty string, a default of "C" (see lang(5)) is used instead of
If any internationalization variable contains an invalid setting, behaves as if all internationalization variables are set to "C". See
environ(5).
International Code Set Support
Single- and multi-byte character code sets are supported.
EXAMPLES
It is frequently desirable to apply to pipelines or lists of commands. This can be done only by placing pipelines and command lists in a
single file, called a shell script. To run the script using
features apply to the entire contents of file. If the shell script file is to be executed often, the need to type can be eliminated by
setting execute permission on file. The script can also be run in the background with interrupts ignored (see sh(1)):
file typically contains normal keyboard command sequences that one would want to continue running in case the terminal disconnects, such
as:
WARNINGS
Be careful to place punctuation properly. For example, in the command form:
applies only to command1. To correct the problem, use the command form:
Be careful of where standard error is redirected. The following command may put error messages on tape, making it unreadable:
whereas
puts the error messages into file
EXIT STATUS
The following exit values are returned:
The command specified by
command was found but could not be invoked
An error occurred in the nohup utility or the specified
command could not be found
Otherwise, the exit status of nohup will be that of the command specified.
SEE ALSO
chmod(1), nice(1), sh(1), signal(5).
STANDARDS CONFORMANCE
nohup(1)