wait(1) 							   User Commands							   wait(1)

NAME

       wait - await process completion

SYNOPSIS

   /bin/sh
       wait [pid]...

   /bin/jsh /bin/ksh /usr/xpg4/bin/sh
       wait [pid]...

       wait [% jobid...]

   /bin/csh
       wait

   ksh93
       wait [job...]

DESCRIPTION

       The  shell itself executes wait, without creating a new process. If you get the error message cannot fork,too many processes, try using the
       wait command to clean up your background processes. If this doesn't help, the system process table is probably full or you  have  too  many
       active  foreground  processes.  There  is a limit to the number of process IDs associated with your login, and to the number the system can
       keep track of.

       Not all the processes of a pipeline with three or more stages are children of the shell, and thus cannot be waited for.

   /bin/sh, /bin/jsh
       Wait for your background process whose process ID is pid and report its termination status. If pid is omitted, all your	shell's  currently
       active background processes are waited for and the return code is 0. The wait utility accepts a job identifier, when Job Control is enabled
       (jsh), and the argument, jobid, is preceded by a percent sign (%).

       If pid is not an active process ID, the wait utility returns immediately and the return code is 0.

   csh
       Wait for your background processes.

   ksh
       When an asynchronous list is started by the shell, the process ID of the last command in each element  of  the  asynchronous  list  becomes
       known in the current shell execution environment.

       If  the	wait utility is invoked with no operands, it waits until all process IDs known to the invoking shell have terminated and exit with
       an exit status of 0.

       If one or more pid or jobid operands are specified that represent known process IDs (or jobids), the wait utility waits until all  of  them
       have  terminated. If one or more pid or jobid operands are specified that represent unknown process IDs (or jobids), wait treats them as if
       they were known process IDs (or jobids) that exited with exit status 127. The exit status returned by the wait utility is the  exit  status
       of the process requested by the last pid or jobid operand.

       The known process IDs are applicable only for invocations of wait in the current shell execution environment.

   ksh93
       wait  with  no  operands, waits until all jobs known to the invoking shell have terminated. If one or more job operands are specified, wait
       waits until all of them have completed. Each job can be specified as one of the following:

       number	   number refers to a process ID.

       -number	   number refers to a process group ID.

       %number	   number refers to a job number

       %string	   Refers to a job whose name begins with string

       %?string    Refers to a job whose name contains string

       %+	   Refers to the current job
       %%

       %-	   Refers to the previous job

       If one ore more job operands is a process id or process group id not known by the current shell environment, wait treats each of them as if
       it were a process that exited with status 127.

OPERANDS

       The following operands are supported:

       pid	The unsigned decimal integer process ID of a command, for which the utility is to wait for the termination.

       jobid	A  job	control  job ID that identifies a background process group to be waited for. The job control job ID notation is applicable
		only for invocations of wait in the current shell execution environment, and only on systems supporting the job control option.

USAGE

       On most implementations, wait is a shell built-in. If it is called in a subshell or separate utility execution environment, such as one	of
       the following,

	 (wait)
	 nohup wait ...
	 find . -exec wait ... ;

       it returns immediately because there is no known process IDs to wait for in those environments.

EXAMPLES

       Example 1 Using A Script To Identify The Termination Signal

       Although the exact value used when a process is terminated by a signal is unspecified, if it is known that a signal terminated a process, a
       script can still reliably figure out which signal is using kill, as shown by the following (/bin/ksh and /usr/xpg4/bin/sh):

	 sleep 1000&
	 pid=$!
	 kill -kill $pid
	 wait $pid
	 echo $pid was terminated by a SIG$(kill -l $(($?-128))) signal.

       Example 2 Returning The Exit Status Of A Process

       If the following sequence of commands is run in less than 31 seconds (/bin/ksh and /usr/xpg4/bin/sh):

	 sleep 257 | sleep 31 &

	 jobs -l %%

       then either of the following commands returns the exit status of the second sleep in the pipeline:

	 wait <pid of sleep 31>
	 wait %%

ENVIRONMENT VARIABLES

       See environ(5) for descriptions of the following environment variables that affect the execution of wait: LANG, LC_ALL,	LC_CTYPE,  LC_MES-
       SAGES, and NLSPATH.

EXIT STATUS

   ksh93
       The following exit values are returned by the wait built-in in ksh93:

       0      wait was invoked with no operands. All processes known by the invoking process have terminated.

       127    job is a process id or process group id that is unknown to the current shell environment.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Committed 		   |
       +-----------------------------+-----------------------------+
       |Standard		     |See standards(5). 	   |
       +-----------------------------+-----------------------------+

SEE ALSO

       csh(1), jobs(1), ksh(1), ksh93(1), sh(1), attributes(5), environ(5), standards(5)

SunOS 5.11							    13 Mar 2008 							   wait(1)