12-05-2011
echo $var when $var is empty is equivalent to just echo - which prints a blank line...
10 More Discussions You Might Find Interesting
1. UNIX for Advanced & Expert Users
Hi,
I have successfully setup my Samba server on my Sun Solaris 8 Sparc machine. My Win2000 workstation is able to see the unix worstation and its shared directory from Network Neighborhood.
However, the Unix workstation appears as Ip address instead of Hostname on my network neighborhood... (5 Replies)
Discussion started by: champion
5 Replies
2. Shell Programming and Scripting
Hi, I'm a newer for this languages, and I have a log file, which is something like this:
35.75.253.207 - - "GET /products/orgonizer/title.png HTTP/1.1" 200 1555 "-" "Mozilla 1.4"
Now, I want to write a shell code to accoplish like ./XXX.sh -N n
n is a number by user input, the code should... (5 Replies)
Discussion started by: pnxi
5 Replies
3. UNIX for Dummies Questions & Answers
I'am doing a tutorial where a simple calculator was given, then i noticed that you can't actually multiply
this is how i have approached the problem so far. i just need if the user enters "*"
to change it to "/*" ,is it possible? i know that * means the name of the last file in the directory... (8 Replies)
Discussion started by: greekozz
8 Replies
4. Shell Programming and Scripting
i have a script that grep for today date
a=`date +"%F"`--------greps current/today date
wat if suppose i want to grep a date for yesterday...
how to do that using the above format: i,e 2008-01-20 (4 Replies)
Discussion started by: ali560045
4 Replies
5. Shell Programming and Scripting
Hi all,
I am looking to create words from a sentence which adhere to a custom search pattern from my website:
Example:
! +! / += ~
where the terms ! = not, +! = AND NOT, += - and equals and ~ = can be like....
Now here is the issue...i want to split a sentence like the one above on... (1 Reply)
Discussion started by: muay_tb
1 Replies
6. Shell Programming and Scripting
pcn linus> ntpq -p
remote refid st t when poll reach delay offset disp
==============================================================================
+smpnn01 ntpsrv1 2 u 829 1024 377 1.46 0.793 0.85
*smpnn02 ntpsrv1 2 u ... (2 Replies)
Discussion started by: arch12
2 Replies
7. Shell Programming and Scripting
Maybe because its Friday, but I can't get a simple while loop to work!
#!bin/bash
i=0
while
do
echo "Hello"
((i++))
done (17 Replies)
Discussion started by: linuxkid
17 Replies
8. Programming
I'm trying to port some code over to unix Solaris. I'm not really a unix programmer so I'm sure this is something straight-forwards but I'm getting the following:
> g++ -c CTrade.cpp
In file included from CTrade.cpp:1:
stdafx.h:6: warning: `#pragma once' is obsolete
CTrade.cpp:4: iostream: No... (1 Reply)
Discussion started by: achartley
1 Replies
9. Shell Programming and Scripting
Hi, I have a very simple script like below:
for n in 10 20 30
do
for a in 30 40 50 60 70 80
do
for r in 2 3 4 5 6 7
do
m=$((r*a))
count=1
while
do
echo "a = " $a ", m = " $m ", n = " $n
... (2 Replies)
Discussion started by: Dark2Bright
2 Replies
10. Shell Programming and Scripting
Hello;
I need to print two previous lines after searching for a reg exp:
awk '/haywood/'
should produce the following
===================
p9J46THe020804 89922 Tue Oct 18 21:06 MAILER-DAEMON
(host map: lookup (haywood.com): deferred)
... (1 Reply)
Discussion started by: delphys
1 Replies
LEARN ABOUT CENTOS
escape
escape(1) Mail Avenger 0.8.3 escape(1)
NAME
escape - escape shell special characters in a string
SYNOPSIS
escape string
DESCRIPTION
escape prepends a "" character to all shell special characters in string, making it safe to compose a shell command with the result.
EXAMPLES
The following is a contrived example showing how one can unintentionally end up executing the contents of a string:
$ var='; echo gotcha!'
$ eval echo hi $var
hi
gotcha!
$
Using escape, one can avoid executing the contents of $var:
$ eval echo hi `escape "$var"`
hi ; echo gotcha!
$
A less contrived example is passing arguments to Mail Avenger bodytest commands containing possibly unsafe environment variables. For
example, you might write a hypothetical reject_bcc script to reject mail not explicitly addressed to the recipient:
#!/bin/sh
formail -x to -x cc -x resent-to -x resent-cc
| fgrep "$1" > /dev/null
&& exit 0
echo "<$1>.. address does not accept blind carbon copies"
exit 100
To invoke this script, passing it the recipient address as an argument, you would need to put the following in your Mail Avenger rcpt
script:
bodytest reject_bcc `escape "$RECIPIENT"`
SEE ALSO
avenger(1),
The Mail Avenger home page: <http://www.mailavenger.org/>.
BUGS
escape is designed for the Bourne shell, which is what Mail Avenger scripts use. escape might or might not work with other shells.
AUTHOR
David Mazieres
Mail Avenger 0.8.3 2012-04-05 escape(1)