Hi ,
I am having one situation in which I need to run some simple unix commands after doing "chroot" command in a shell script. Which in turn creates a new shell.
So scenario is that
- I need to have one shell script which is ran as a part of crontab
- in this shell script I need to do a... (2 Replies)
I need to know these UNIX Shell Commands with the appropriate parameters.
List the files in current directory beginning with extension .har. (% ls .har)
View text file "hosts.copy" which spans multiple screens.
Execute the batch file "tapeeject.bat"
Copy all files from current... (2 Replies)
Hi,
I know that to create a pdf file I can use the txt2pdf command.
But if I would change an existing pdf file, by inserting lines in particular positions of this file, what can I use? And How? (3 Replies)
When my script deals with large input files like 22Gb or 18 GB the basic commands like sort or join fails when run from inside the shell scripts. Can there be any specific reason for this?
For e.g.
sort -u -t "," -k1,1 a.csv > a.csv.uniq"
sort -u -t "," -k1,1 b.csv > b.csv.uniq"
The... (3 Replies)
Hello.
I found a Unix script on this site that calculates a date that is 2 months earlier from today. I'm using that script and writing the value to a file called 2monthsago.txt. I want to use that value in another script. Below is my attempt at doing that and the results.
My Script:
... (1 Reply)
can you help me to create a phone book with add, delete, modify with first name, last name, middle name, phone no(multiple ph no), address, email address, notes or comments to store about the contact and groups that hold for the contact..
i am new to this linux environment. please guide me.
... (1 Reply)
Hello, ive recently finished university and im working as an assistant teacher in a secondary school. ive been given the objective t o give the students an assignment with a simple shell program in C/C++ with the support for several commands the Shell must also have the ability of processing... (1 Reply)
My webpage is hosted from perlscript(homepage.pl), i want to add piece of html code in the footer of the homepage. I simply pasted the html code at the end of the perl script as below...
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close(OUTSQL);
... (4 Replies)
Hello. I need help trying to create a script in UNIX to do the following steps. I don't know which commands to input to achieve this.
1. In a directory tree, I want to duplicate all .txt files into the same directory, so 2 of each file exists in each directory where there is a .txt file
... (4 Replies)
Hi,
I wrote a simple script, which will call other scripts or run commands on a UNIX server. my script has multiple steps/commands with some delay in between.
I usually get some email notifications after the successful execution of each step.
**My intention is to get email alerts when it is... (5 Replies)
Discussion started by: System Admin 77
5 Replies
LEARN ABOUT REDHAT
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
}
SEE ALSO
break(n), continue(n), for(n), foreach(n)
KEYWORDS
boolean value, loop, test, while
Tcl while(n)