Signal Processing Post: 8125

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Top Forums UNIX for Dummies Questions & Answers Signal Processing Post 8125 by sanjay92 on Friday 5th of October 2001 05:24:59 PM

10-05-2001

sanjay92

Guest

Hello Perderabo,
---------------------------------------------------
"
I know that my method leaves a sleep process running if the timed command completes in time. I think that's harmless. It will be reaped by init when it exits. That's the only real cost of a very easily coded solution. Capturing and killing that last pid will drive script back up in complexity.
"
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Does sleep process creates any kind of overhead for the unix system.

When I execute the following command (sleep 30; echo hello) &
, it create the two processes one is the shell process and the other is sleep process and the sleep process pid is always 1 greater than the shell process pid. Is it always true ?.

sanjay92

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wait

wait(1) 						      General Commands Manual							   wait(1)

NAME

       wait - await process completion

SYNOPSIS

       [pid]

DESCRIPTION

       If  no argument is specified, waits until all processes (started with of the current shell have completed, and reports on abnormal termina-
       tions.  If a numeric argument pid is given and is the process ID of a background process, waits until that process has  completed.   Other-
       wise, if pid is not a background process, exits without waiting for any processes to complete.

       Because the system call must be executed in the parent process, the shell itself executes without creating a new process (see wait(2)).

   Command-Line Arguments
       supports the following command line arguments:

	      The unsigned decimal integer process
			  ID of a command, whose termination is to wait for.

WARNINGS

       Some processes in a 2-or-more-stage pipeline may not be children of the shell, and thus cannot be waited for.

SEE ALSO

       csh(1), ksh(1), sh-posix(1), sh(1), wait(2).

STANDARDS CONFORMANCE

																	   wait(1)