Hi All,
I search the forum for my query, Glad that got solution to it. But i really want to understand how does this command work.
sed -e ':a' -e 's/\("*\),\(*"\)/\1~\2/;ta'
Basically it is replacing all the comma(,) characters in between quotes with a tilde.
Specially what does ':a' ,... (2 Replies)
Hi Guys,
I like to know if i have a process which triggers 10 different child processes.
How to identify out of the 11 processes running which is the parent process and what are the child process?
And if i kill the parent process will the child process be killed.. if not is there a way to... (2 Replies)
I am trying to create a basic script that converts an Oracle script into a Sybase script.
The only things im changing are Datatypes and the to_char and to_date functions.
I am not really 100% sure of the way it works. I have tried running the functions through a loop to replace each word line... (6 Replies)
hi
i was moving a file from one directory to another with the following cmmand
mv /home/hsghh/dfd/parent/file.txt .
while doing so i i accidently
mv /home/hsghh/dfd/dfd .
although i gave ctrl c and terminate the move command some of the file are missing in the parent directory and... (1 Reply)
Hi
I have a questions related 2 commands : 'du' and 'ls'.
Why is the difference between output of 'du' and 'ls' cmd's ?
Command 'du' :
------------------
jakubn@server1 /home/jakubn $ du -s *
4 engine.ksh
1331 scripts
'du -s *' ---> shows block count size on disk (512 Bytes... (5 Replies)
After running nm command on any object file from out put can we get to know that wheather a symbol is a call to a function or definition of function ?
I am searching a class and function definitions inside many .so files.
I have 3 files which contain the symbol but I don't know wheather they... (2 Replies)
Hi Friends,
I need a small help in understanding the below sed command.
$ cat t4.txt
1 root 1 58 0 888K 368K sleep 4:06 0.00% init
1 root 1 58 0 888K 368K sleep 4:06 0.00% init last
$ sed 's/*$//' t4.txt
1 root 1 58 0 888K ... (3 Replies)
I have the following line of code that works wonders. I just don't completely understand it as I am just starting to learn regex. Can you help me understand exactly what is happening here?
find . -type f | grep -v '^\.$' | sed 's!\.\/!!' (4 Replies)
Hi,
can some one suggest me,how "sed" is managed to delete the second field here.
Any explanation on , how the below code is working would be appreciated.
sed 's/^\(*\)::/\1::/' /etc/passwd
sed 's/*:/:/2' /etc/passwd (14 Replies)
Hi Guys,
Could you please kindly explain what exactly the below SED command will do ?
I am quite confused and i assumed that,
sed 's/*$/ /'
1. It will remove tab and extra spaces .. with single space.
The issue is if it is removing tab then it should be Î right ..
please assist.... (3 Replies)
Discussion started by: Nandy
3 Replies
LEARN ABOUT BSD
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)