if VAR is already set (and not null), will be reset with its own value; else will be set to "default_value". In your case, you can put 0 for this value.
Another less elegant but maybe more clear way is:
I am writing a shell script that executes another script by fetching it over the network and piping its contents into sh (ftp -o - $script | sh; or wget -O - |sh). Since this bypasses putting the script on the filesystem, this means I can't source the script directly (using . ), but rather it... (1 Reply)
hi all
i have joined new to the group.
i have set an variable in my bashrc file.
.bashrc
PROGHOME=/home/braf/braf/prog
export PROGHOME
but while using it in my shell script its path is not taken and i had to explicitly give the export command to set the path.
in my script... (8 Replies)
Hello guys.
In my script, i have the following code:
echo "The tarfile contains these directorys"
tar -tf file.tar > tarlist.txt
cat tarlist | awk -F/ '{print $1 "/" $2}' | nl
echo "Enter path of the directory you want to extract or just press enter to extract everything: "
read path... (1 Reply)
Can someone tell me why I'm getting error when I try to run this?
#!/bin/csh -f
source ~/.cshrc
#
set SQLPLUS = ${ORACLE_HOME}/bin/sqlplus
#
set count=`$SQLPLUS -s ${DB_LOGIN} << END
select count(1) from put_groups where group_name='PC' and description='EOD_EVENT' and serial_number=1;... (7 Replies)
first of all, thanks to all on this board, it has been a huge resource to answer most of my questions!
I am stuck on something that should really be simple, and was looking for some help.. I am using KSH on solaris and working on a script to move containers from server to server. Where i am... (4 Replies)
I have a shell script I want to run that will set environment variables based on the value of an input variable submitted when the shell script is called. For example:
$ mgenv.sh prod
This would set environment variables for prod
$ mgenv.sh test
This would set environment variables... (1 Reply)
I am working on a perl script that is used to update a list of hosts to a certain file but I am having an issue when I try to perform a check to make sure the user enters valid information. The following is what I have currently written for the script:
IPINPUT:
print "Enter IP Address: ";... (2 Replies)
greetings,
i have a sh script that calls a python script. the sh script sets an env variable BIN:
export BIN=bin64i need to get that BIN variable's value and use it within this python script. anyone know how to do this? thanx in advance. (5 Replies)
Hi,
Will following set up work in bash script? I've got errors if assigning following binary command to a variable. But on the other hand, COMMAND="ls" works. Any explanation please? How can I assign binary command to a variable COMMAND then I can just call ${COMMAND}?
COMMAND="rsync"... (3 Replies)
Discussion started by: hce
3 Replies
LEARN ABOUT CENTOS
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)