Variable gets auto updated after function execution Post: 303036761

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Top Forums UNIX for Beginners Questions & Answers Variable gets auto updated after function execution Post 303036761 by MadeInGermany on Wednesday 10th of July 2019 03:38:44 PM

07-10-2019

Registered User

grep -q might not work with all grep versions. What is your OS?

Code:

tail -f $UMPath/data/nirvana.log | while read line
do
done

Several problems with that.
The pipe forces the while-do-done block into a sub shell.

While the return should work an exit can produces different results, dependent on the shell. BTW what shell and OS do you use?
Your main problem: changes on variables are not copied back to the main shell.

Then, if the sub shell terminates, it sends a SIGPIPE to the tail -f that hopefully terminates.
The following eliminates some problems

Code:

# Watch the log file for the initialization string
getline()
{
# use the portable printf in favor of echo -e
printf "\nNow watching nirvana log for the Started Nirvana Realm string"
# tail -f will hopefully terminate
tail -f $UMPath/data/nirvana.log |
# the pipe forces the while-do-done into a sub shell:
# variables are not returned but a return value should work
while read line
do
    case "$line" in
    *"Realm Server Startup sequence completed"*)
        printf "\nFound: %s\n\n" "$line"
        return 0
    ;;
    *"Server shutdown"*)
        printf "\nFound: %\n\n" "$line"
        return 1
    ;;
    esac
done
}
# act on the return value
if getline
then
    echo "UM is now up and running"
else
    echo "UM failed to start. Please check"
    rval=1
fi
exit $rval

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LEARN ABOUT X11R4

xkbsetautoresetcontrols

XkbSetAutoResetControls(3)					   XKB FUNCTIONS					XkbSetAutoResetControls(3)

NAME

       XkbSetAutoResetControls - Changes the current values of the AutoReset control attributes

SYNOPSIS

       Bool XkbSetAutoResetControls ( dpy, changes, auto_ctrls, auto_values )
	     Display * dpy ;
	     unsigned int  changes ;
	     unsigned int * auto_ctrls ;
	     unsigned int * auto_values ;

ARGUMENTS

       - dpy  connection to X server

       - changes
	      controls for which to change auto-reset values

       - auto_ctrls
	      controls from changes that should auto reset

       - auto_values
	      1 bit => auto-reset on

DESCRIPTION

       XkbSetAutoResetControls	changes the auto-reset status and associated auto-reset values for the controls selected by changes.  For any con-
       trol selected by changes, if the corresponding bit is set in auto_ctrls, the control is configured to auto-reset when the client exits.	If
       the  corresponding  bit	in  auto_values is on, the control is turned on when the client exits; if zero, the control is turned off when the
       client exits. For any control selected by changes, if the corresponding bit is not set in auto_ctrls, the  control  is  configured  to  not
       reset when the client exits.

       For example:

       To leave the auto-reset controls for StickyKeys the way they are:

	    ok = XkbSetAutoResetControls(dpy, 0, 0, 0);

       To change the auto-reset controls so that StickyKeys are unaffected when the
       client exits:

	    ok = XkbSetAutoResetControls(dpy, XkbStickyKeysMask, 0, 0);

       To change the auto-reset controls so that StickyKeys are turned off when the
       client exits:

	    ok = XkbSetAutoResetControls(dpy, XkbStickyKeysMask, XkbStickyKeysMask, 0);

       To change the auto-reset controls so that StickyKeys are turned on when the
       client exits:

	    ok = XkbSetAutoResetControls(dpy, XkbStickyKeysMask, XkbStickyKeysMask,
       XkbStickyKeysMask);

       XkbSetAutoResetControls	backfills auto_ctrls and auto_values with the auto-reset controls for this particular client. Note that all of the
       bits are valid in the returned values, not just the ones selected in the changes mask.

X Version 11							   libX11 1.2.1 					XkbSetAutoResetControls(3)

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