How can I sort the data file and then save it back into itself without having to create a temporary file '0' and still have the newline characters that separate each row remain?
Why do you feel creating a temp file is a constraint ?
even sort uses temp files
check out the option -T
Hi
I am using nohup command in script(say nohup ls- ltr > somefile 2>&1 & ). I dont want any kind of output to be displayed on screen. When i tried the above nohup it still gives me some out put on screen like
2991
Done >somefile 2>&1
Please you let me know what is... (3 Replies)
Hi,
When I run the following command in terminal it works. The string TEST is appended to a file silently.
echo TEST | tee -a file.txt &>/dev/null
However, when I paste this same line to a file, say shell1.sh, and use bourne shell .
I run this file in terminal, ./shell1.sh.
However I... (1 Reply)
I am using tar command to append daily database backups on tape. "tar --append " command help me to do this.
But tar --append command does not produce any output on stdout if it succeed.
I want the output for that appended command to a log file.
This log file should contain only the name of the... (0 Replies)
Hi All,
I want to display content on command promt and also write in file.
For that iI ahve to write two sentence
echo "XXXXXXX"
echo "XXXXXXXX" >> 1.txt
Is there any way to write in one echo statement (1 Reply)
I am trying to write a simple script which prints some output, but also saves the same in a logfile.
echo hello
echo hello >> logfile
Is there anyway i Can write single sentence of code and get the same result:
( i am using CSH ) (4 Replies)
Dear All,
./waf --run scratch/myfirst > log.out 2>&1
The above is a command line to redirect the output to a file called log.out.
what is the 2>&1 part for ?
Thank you (2 Replies)
Hello,
I'm new to Unix (working with OS X 10.8.5) and therefore at the beginning of my adventure. If I ask something stupid, then this is not intentional, but simple nescience. :rolleyes:
I have a problem with the redirection of text file content to echo. I was experimenting with redirection... (6 Replies)
Hi,
I have a peculiar issue w.r.t redirecting the command output to a file when using loop.
I am redirecting command output to same file in a series of if condition statements, but if one block of if condition statement writes the log to the file , the subsequent block of if condition... (7 Replies)
Discussion started by: ananan
7 Replies
LEARN ABOUT POSIX
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)