The problem - save for what Don Cragun already explained - "$$" is short for "the PID of the current process" and interpreted by the shell that way. YOu can test that with the following script:
Start this script and from another terminal do:
substituting "<PID>" with the displayed number. You will see that the shell process has exactly this process number. (Stop the script with "CTRL-C" afterwards.)
So, even if you would manage to assign the value to such an ill-named variable you would have no possibility to retrieve it from there because any time you write "$$" it will be translated to the PID. If you want to simply have the "$$" in the output you can use "\" to escape the "$":
I am trying to write a script that prompts users for date and time, then process the gzip file into awk. During the ksh part of the script another file is created and needs to be processed with a different set of pattern matches then I need to combine the two in the end. I'm stuck at the part... (6 Replies)
Hello, I know how to join multiple files using the cat function. I want to do something a little more advanced. Basically I want to put the filename in the first column...
One thing to note is that the file is tab delimited.
e.g.
file1.txt
joe 1 4 5 6 7 3
manny 2 3 4 5 6 7
... (4 Replies)
Hi all,
I have a list of xml file. I need to split the files to a different files when see the <ko> tag.
The list of filename are
B20090908.1100-20090908.1200_CDMA=1,NO=2,SITE=3.xml
B20090908.1200-20090908.1300_CDMA=1,NO=2,SITE=3.xml
B20090908.1300-20090908.1400_CDMA=1,NO=2,SITE=3.xml
... (3 Replies)
Good afternoon,
I have been searching the web, and these forums for help. I will try my best to explain the issue, and what my desired results are.
I am doing queries in MYSQL, and need the output to be sent to a file. That file needs to have things with the same ID on the same line. To... (14 Replies)
Hi,
I generated many figures in .png format (approximately 120). Right now I need to pair the figures on a single page so that the files with the same file name (i.e. jack) that end with .matrix.png are placed on the left and .cdt.png is on the right (so jack.matrix.png with jack.cdt.png... (6 Replies)
Hi All,
Thanks in Advance
I am working on a shell script. I need some assistance.
My Requirement:
1) There are some set of files in a directory like given below
OTP_UFSC_20120530000000_acc.csv
OTP_UFSC_20120530000000_faf.csv
OTP_UFSC_20120530000000_prom.csv... (0 Replies)
Hi All,
Thanks in Advance
I am working on a shell script. I need some assistance.
My code:
if
then
set "subscriber" "promplan" "mapping" "dedicatedaccount" "faflistSub" "faflistAcc" "accumulator"\
"pam_account";
for i in 1 2 3 4 5 6 7 8;... (0 Replies)
I already manage to get the output that i want.. but wat if removing all the pipes and convert it 1 liner with less pipes. My command below can get the ouput that i want. i just want to remove the pipes or less pipes.
#cat file1
us-west-2a running i-3397a421... (2 Replies)
What are the steps you need to take when you put an old HD in a new computer? I just did this. Every time it makes it to the windows boot screen then restarts. I have a bunch of old engineering software that is not compatible with the newer versions of windows. I figured this out after I bought... (6 Replies)
Discussion started by: cokedude
6 Replies
LEARN ABOUT ULTRIX
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)