svcadm(1M) 을 검색하려면 섹션에서 1M 을 선택하고, 맨페이지명에 svcadm을 입력하고 검색을 누른다.
nohup
Name
nohup - run a command immune to hangups
Synopsis
/usr/bin/nohup command [argument]...
/usr/bin/nohup -p [-Fa] pid [pid]...
/usr/bin/nohup -g [-Fa] gpid [gpid]...
/usr/xpg4/bin/nohup command [argument]...
Description
The nohup utility invokes the named command with the argu-
ments supplied. When the command is invoked, nohup arranges
for the SIGHUP signal to be ignored by the process.
When invoked with the -p or -g flags, nohup arranges for
processes already running as identified by a list of process
IDs or a list of process group IDs to become immune to hang-
ups.
The nohup utility can be used when it is known that command
takes a long time to run and the user wants to log out of
the terminal. When a shell exits, the system sends its chil-
dren SIGHUP signals, which by default cause them to be
killed. All stopped, running, and background jobs ignores
SIGHUP and continue running, if their invocation is preceded
by the nohup command or if the process programmatically has
chosen to ignore SIGHUP.
The nohup utility causes processes to ignore SIGHUP but does
not in any way protect those processes from other signals.
Since modern shells sometimes send signals other than SIGHUP
upon logout, it is possible for jobs running under
/usr/bin/nohup to be killed when the controlling shell
exits.
/usr/bin/nohup
Processes run by /usr/bin/nohup
are immune to SIGHUP (hangup) and
SIGQUIT (quit) signals.
/usr/bin/nohup -p [-Fa]
Processes specified by ID are
made immune to SIGHUP and
SIGQUIT, and all output to the
controlling terminal is
redirected to nohup.out. If -F is
specified, nohup forces control
of each process. If -a is speci-
fied, nohup changes the signal
disposition of SIGHUP and SIGQUIT
even if the process has installed
a handler for either signal.
/usr/bin/nohup -g [-Fa]
Every process in the same process
group as the processes specified
by ID are made immune to SIGHUP
and SIGQUIT, and all output to
the controlling terminal is
redirected to nohup.out. If -F is
specified, nohup forces control
of each process. If -a is speci-
fied, nohup changes the signal
disposition of SIGHUP and SIGQUIT
even if the process has installed
a handler for either signal.
/usr/xpg4/bin/nohup
Processes run by
/usr/xpg4/bin/nohup are immune to
SIGHUP.
The nohup utility does not
arrange to make processes immune
to a SIGTERM (terminate) signal,
so unless they arrange to be
immune to SIGTERM or the shell
makes them immune to SIGTERM,
they receive it.
If nohup.out is not writable in
the current directory, output is
redirected to $HOME/nohup.out. If
a file is created, the file has
read and write permission (600.
See chmod(1). If the standard
error is a terminal, it is
redirected to the standard out-
put, otherwise it is not
redirected. The priority of the
process run by nohup is not
altered.
Options
The following options are supported:
-a
Always changes the signal disposition of target
processes. This option is valid only when specified
with -p or -g.
-F
Force. Grabs the target processes even if another pro-
cess has control. This option is valid only when
specified with -p or -g.
-g
Operates on a list of process groups. This option is
not valid with -p.
-p
Operates on a list of processes. This option is not
valid with -g.
Operands
The following operands are supported:
pid
A decimal process ID to be manipulated by nohup
-p.
pgid
A decimal process group ID to be manipulated by
nohup -g.
command
The name of a command that is to be invoked. If
the command operand names any of the special
shell_builtins(1) utilities, the results are
undefined.
argument
Any string to be supplied as an argument when
invoking the command operand.
Usage
Caution should be exercised when using the -F flag. Imposing
two controlling processes on one victim process can lead to
chaos. Safety is assured only if the primary controlling
process, typically a debugger, has stopped the victim pro-
cess and the primary controlling process is doing nothing at
the moment of application of the proc tool in question.
Examples
Example 1 Applying nohup to Pipelines or Command Lists
It is frequently desirable to apply nohup to pipelines or
lists of commands. This can be done only by placing pipe-
lines and command lists in a single file, called a shell
script. One can then issue:
example$ nohup sh file
and the nohup applies to everything in file. If the shell
script file is to be executed often, then the need to type
sh can be eliminated by giving file execute permission.
Add an ampersand and the contents of file are run in the
background with interrupts also ignored (see sh(1)):
example$ nohup file &
Example 2 Applying nohup -p to a Process
example$ long_running_command &
example$ nohup -p `pgrep long_running_command`
Example 3 Applying nohup -g to a Process Group
example$ make &
example$ ps -o sid -p $$
SID
81079
example$ nohup -g `pgrep -s 81079 make`
Environment Variables
See environ(5) for descriptions of the following environment
variables that affect the execution of nohup: LANG, LC_ALL,
LC_CTYPE, LC_MESSAGES, PATH, NLSPATH, and PATH.
HOME
Determine the path name of the user's home direc-
tory: if the output file nohup.out cannot be created
in the current directory, the nohup command uses the
directory named by HOME to create the file.
Exit Status
The following exit values are returned:
126
command was found but could not be invoked.
127
An error occurred in nohup, or command could not be
found
Otherwise, the exit values of nohup are those of the command
operand.
Files
nohup.out
The output file of the nohup execution if
standard output is a terminal and if the
current directory is writable.
$HOME/nohup.out
The output file of the nohup execution if
standard output is a terminal and if the
current directory is not writable.
Attributes
See attributes(5) for descriptions of the following attri-
butes:
/usr/bin/nohup
tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) ATTRI-
BUTE TYPEATTRIBUTE VALUE _ Availabilitysystem/core-os _
CSIEnabled
/usr/xpg4/bin/nohup
tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) ATTRI-
BUTE TYPEATTRIBUTE VALUE _ Availabilitysystem/xopen/xcu4 _
CSIEnabled _ Interface StabilityCommitted _ StandardSee
standards(5).
See Also
bash(1), batch(1), chmod(1), csh(1), disown(1), ksh88(1),
nice(1), pgrep(1), proc(1), ps(1), sh(1), shell_builtins(1),
setpgrp(1), signal(3C), proc(4), attributes(5), environ(5),
standards(5)
Warnings
If you are running the Korn shell (ksh88(1)) as your login
shell, and have nohup'ed jobs running when you attempt to
log out, you are warned with the message:
You have jobs running.
You need to log out a second time to actually log out. How-
ever, your background jobs continues to run.
Notes
The C-shell (csh(1)) has a built-in command nohup that pro-
vides immunity from SIGHUP, but does not redirect output to
nohup.out. Commands executed with `&' are automatically
immune to HUP signals while in the background.
nohup does not recognize command sequences. In the case of
the following command,
example$ nohup command1; command2
the nohup utility applies only to command1. The command,
example$ nohup (command1; command2)
is syntactically incorrect.