It is good practise to issue a wait statement after the start of all the background processes to stop the parent shell from exiting before all of its children have finished.
Hello Everybody,
Please help.
I was trying to automate the use of a third-party given shell script. The script is written to be used at run-time to collect a few variables to be provided by the user through key board, in the fashion as below:
./runcommand
please provide a file name to... (6 Replies)
Scenario:
I have two PCs (named as A & B) which would send some traps to my third PC (named as C).
In PC C, I have to write a shell script such that it should accept the datas from both the PC-A & B parallely.
So my question is, is it possible to have two different child threads/tasks... (2 Replies)
Hello everyone,
I have two types of files in a directory:
*.txt
*.info
I have a perl script that uses these two files as arguments, and produces a result file:
perl myScript.pl abc.txt abc.xml
How can I run this script (in a "for" loop , looping through both types of files)... (4 Replies)
hi,
i have folder backup and it contains 3 sub-directories , i want to compare
/backup/1 with /recover/1 and /backup/2 with /recover/2 etc .
parallelly with using shell scripting .
pls help me
thanks (2 Replies)
I would like to call a function called CIRCLE which is further beind called by other function but in a loop that CIRCLE fuction is being called. And this CIRCLE function starts another process which takes 3 hours to complete again, if i put that process in nohup &, I can go to the next command... (2 Replies)
the scenario is -
If I pass 3 three arguments( run time) , it should list all .txt files from a path to temp file
if I pass 2 arguments ( run time) , it should list all .csv files from the same path to another temp file
the above scenario should be handled in single code and also I dont know ... (2 Replies)
I need to run a local shell script on a remote machine. I am able to achieve that by executing the command
> ssh -qtt user@host < test.sh
However, when I try to pass arguments to test.sh it fails.
Any pointers would be appreciated. (7 Replies)
Hi ,
I have 4 scripts example script1,script2,script3,script4 .
I have to run script1,script2 and script3 parallely since this 3 scripts dont have dependencies .
Once script1,script2 and script3 got completed successfully , I have to trigger script4.
Can someone help me on this how to... (10 Replies)
Hi,
I need to write a Shell Script wherein i will connect to a DB2 Database and run multiple DB procedures. I know how to do in a way where procedures will be called one after the other, like when first procedure finishes, second will be executed.
But what i want is to run them at the same time... (11 Replies)
Discussion started by: Neelkanth
11 Replies
LEARN ABOUT MOJAVE
tcl_waitpid
Tcl_DetachPids(3) Tcl Library Procedures Tcl_DetachPids(3)__________________________________________________________________________________________________________________________________________________NAME
Tcl_DetachPids, Tcl_ReapDetachedProcs, Tcl_WaitPid - manage child processes in background
SYNOPSIS
#include <tcl.h>
Tcl_DetachPids(numPids, pidPtr)
Tcl_ReapDetachedProcs()
Tcl_Pid
Tcl_WaitPid(pid, statusPtr, options)
ARGUMENTS
int numPids (in) Number of process ids contained in the array pointed to by pidPtr.
int *pidPtr (in) Address of array containing numPids process ids.
Tcl_Pid pid (in) The id of the process (pipe) to wait for.
int *statusPtr (out) The result of waiting on a process (pipe). Either 0 or ECHILD.
int options (in) The options controlling the wait. WNOHANG specifies not to wait when checking the process.
_________________________________________________________________DESCRIPTION
Tcl_DetachPids and Tcl_ReapDetachedProcs provide a mechanism for managing subprocesses that are running in background. These procedures
are needed because the parent of a process must eventually invoke the waitpid kernel call (or one of a few other similar kernel calls) to
wait for the child to exit. Until the parent waits for the child, the child's state cannot be completely reclaimed by the system. If a
parent continually creates children and doesn't wait on them, the system's process table will eventually overflow, even if all the children
have exited.
Tcl_DetachPids may be called to ask Tcl to take responsibility for one or more processes whose process ids are contained in the pidPtr
array passed as argument. The caller presumably has started these processes running in background and does not want to have to deal with
them again.
Tcl_ReapDetachedProcs invokes the waitpid kernel call on each of the background processes so that its state can be cleaned up if it has
exited. If the process has not exited yet, Tcl_ReapDetachedProcs does not wait for it to exit; it will check again the next time it is
invoked. Tcl automatically calls Tcl_ReapDetachedProcs each time the exec command is executed, so in most cases it is not necessary for
any code outside of Tcl to invoke Tcl_ReapDetachedProcs. However, if you call Tcl_DetachPids in situations where the exec command may
never get executed, you may wish to call Tcl_ReapDetachedProcs from time to time so that background processes can be cleaned up.
Tcl_WaitPid is a thin wrapper around the facilities provided by the operating system to wait on the end of a spawned process and to check a
whether spawned process is still running. It is used by Tcl_ReapDetachedProcs and the channel system to portably access the operating sys-
tem.
KEYWORDS
background, child, detach, process, wait
TclTcl_DetachPids(3)