It makes no sense to put a background statement in backticks, is the problem. How could it possibly set the variable until the process completes? So it either it fills the variable with a blank and puts the program in the background, or waits anyway. Neither gets you what you want.
You could replace the sleep with :, which will cause it to just loop forever until either condition breaks the loop. This will cause 100% CPU usage while it's waiting for the timeout. If you run your script with 'nice ./script.sh' that may be tolerable.
Since it needs to be POSIX you'll have to replace my math statement too.
I have a command which will run fine in a unix command prompt. Can you tell how to interprete this command inside perl script......
The command is :
perl -pe 's/(\|333\}.*)\}$/$1|1.6}/' FIA.txt
This will search for the number 333 and appends 1.6 at the end of that line....... (1 Reply)
I'm new to Linux. I have a bash script that invokes an executable. I'd like use the SCRIPT command inside the script and exit out of the script command after it writes to the file. Does this make sense? Below is an example of the contents of my script.
#BEGIN SCRIPT
script typescript... (6 Replies)
Hi everyone,
when executing this command in unix:
echo "WM7 Fatal Alerts:", $(cat query1.txt) > a.csvIt works fine, but running this command in a shell script gives an error saying that there's a syntax error.
here is content of my script:
tdbsrvr$ vi hc.sh
"hc.sh" 22 lines, 509... (4 Replies)
Hi All,
Is there any way to monitor a command inside shell script ? I have a script inside which I have a tar command which zips around 200GB data.
tar zcvf $Bckp_Dir/$Box-BaseBackup-$Day.tar.gz * --exclude 'dbserver_logs/*' --exclude postmaster.pid --exclude 'pg_xlog/*'
I want to... (3 Replies)
Hi,
I have a script file in server A. Inside the script file, I first have a ssh command that will connect to a remote server B. In the same script file itself, I have a sequence of commands that has to be run in server B. I am embedding these commands in the script file that I have in server A.... (2 Replies)
hii,,
I am trying to automate jira. during my scripting using bash script, in the terminal i got the terminal message like this:
"Configure which ports JIRA will use.
JIRA requires two TCP ports that are not being used by any other
applications on this machine. The HTTP port is where you... (1 Reply)
Hi ,
DIR1 has only one file with .txt extension , trying to get the size of that file using the following script
#!/bin/ksh
foldr_1="/etc/DIR1"
#echo "$foldr_1"
sze_fdr1=$(ls -ltr foldr_1/*.txt |awk '{ print $5 }')
echo "$sze_fdr1"
After executing the above script getting... (1 Reply)
hi,
how can i know whether a command inside an sftp script has failed or not?
i have a sftp expect script
#!/usr/bin/expect
spawn /usr/bin/sftp abc@ftp.abc.com
expect "sftp>"
send "cd dir\r"
expect "sftp>"
send "mput abc.txt\r"
expect "sftp>"
send "mput def.xls\r"
expect "sftp>"... (5 Replies)
My script needs to take a folder path to the location of a C program, and run the program until the user selects exit in his C program. The script needs to create a transcript to a text file while the C program is running.
Creating a transcript can be easily done with the script command but it... (2 Replies)
Discussion started by: syntax_eror
2 Replies
LEARN ABOUT SUSE
while
while(n) Tcl Built-In Commands while(n)
__________________________________________________________________________________________________________________________________________________NAME
while - Execute script repeatedly as long as a condition is met
SYNOPSIS
while test body
_________________________________________________________________DESCRIPTION
The while command evaluates test as an expression (in the same way that expr evaluates its argument). The value of the expression must a
proper boolean value; if it is a true value then body is executed by passing it to the Tcl interpreter. Once body has been executed then
test is evaluated again, and the process repeats until eventually test evaluates to a false boolean value. Continue commands may be exe-
cuted inside body to terminate the current iteration of the loop, and break commands may be executed inside body to cause immediate termi-
nation of the while command. The while command always returns an empty string.
Note: test should almost always be enclosed in braces. If not, variable substitutions will be made before the while command starts execut-
ing, which means that variable changes made by the loop body will not be considered in the expression. This is likely to result in an
infinite loop. If test is enclosed in braces, variable substitutions are delayed until the expression is evaluated (before each loop iter-
ation), so changes in the variables will be visible. For an example, try the following script with and without the braces around $x<10:
set x 0
while {$x<10} {
puts "x is $x"
incr x
}
EXAMPLE
Read lines from a channel until we get to the end of the stream, and print them out with a line-number prepended:
set lineCount 0
while {[gets $chan line] >= 0} {
puts "[incr lineCount]: $line"
}
SEE ALSO
break(n), continue(n), for(n), foreach(n)
KEYWORDS
boolean value, loop, test, while
Tcl while(n)