I understand that a Here Document will redirect all of the lines between the beginning marker for the here document and the ending marker into the command specified just as if the text were coming from standard input.
I am trying to understand the Here Document with this example:
# Menu file... (3 Replies)
Hello,
I want to know the use of the here document with the << operator.
Tried to go through some books but the concept was not clear.
Please can any1 expalin me this with a simple example.
Thanks,
Rahul. (6 Replies)
Hi :)
how can I use here doc to use ssh?
I am facing a problem with the below script:
#!/bin/bash
ssh hosein@localhost << *
123456
*
"123456" is my password
Thanks (2 Replies)
Plz can somebody give me the shell and perl scripting documents,i need to start the scrpts learning.now i know about the linux commands,but need help in putting the same in the scripting with do,if,while and also using diffrent commands in the scrpipts,pls help.. (3 Replies)
Here is my problem: can we set the variables in the HERE DOCUMENT? I have tried but failed. Any one has good comments please let me know.
#!/bin/csh -f
pbrun -u xmgbrk runshell <<!
@ $num1 = `wc -l /home/tpltp/csh/scripts/who.csh`
echo "$num1"
if ( $num1 > 0 ) then
echo $num1 | tee -a... (1 Reply)
So in my shell i execute:
{ while true; do echo string; sleep 1; done } | read line This waits one second and returns.
But
{ while true; do /bin/echo string; sleep 1; done } | read line continues to run, and doesn't stop until i kill it explicitly.
I have tried this in bash as well as zsh,... (2 Replies)
Bit of a weird one i suppose, i want to use an echo inside an echo... For example...
i have a script that i want to use to take users input and create another script. Inside this script it creates it also needs to use echos...
echo "echo "hello"" >$file
echo "echo "goodbye"" >$file
... (3 Replies)
echo `echo ` doesn't echoes anything. And it's logic. But
echo `echo `echo ` ` does echoes "echo". What's the logic of it? the `echo `echo ` inside of the whole (first) echo, echoes nothing, so the first echo have to echo nothing but echoes "echo"
(too much echoing :P):o (2 Replies)
Can we use a here document inside a here document?
Something like this
ssh user@remotehost << REMOTE
sudo vserver vsernamename enter << VSERVER
perform actions on vserver.
VSERVER
REMOTE (6 Replies)
ssh $USR@$host /bin/bash <<\EOF >> ship-error.txt
awk 'BEGIN{f=0} !f { s=$0; sub(/,.+/, "", s); gsub(//, " ", s); t=(systime()-mktime(s)); if(t<=14400) f=1 } f ' /logs/shiperror.log
EOF
I want to use an echo command within the EOF. Is this possible?
something like this: So that it prints... (3 Replies)
Discussion started by: Deepthz
3 Replies
LEARN ABOUT FREEBSD
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)