I still can not grasp benefits of using
What's the point?
According to the man page of OS X i found in the net "-n" prevents the mv command to overwrite already existing files. That means: if you have files A, B and C and you do a
you will end up with three files again, B, C and D (the former A). Whereas, when you issue:
you will end up with only two files: B (the former A) and C. The original B will be wiped out. This may sometimes be the desired result, but sometimes it may not. To guard against accidentally wiping out a file you might want to keep is the reason "-n" exists.
i'm using SunOS 5.7 and I know theres a ls option for seeing what kind of files are in a directory. I was wondering if there was a ls option that could see if the files are txt or files that can be opened in vi (1 Reply)
How can I use the 'ps' command to view current sessions but only for a given process/user, with the -u parm?
In older versions of Unix, this used to work, but not in Sun Solaris.
Thanks (4 Replies)
Running HP 11.31 on a HP3600. But when I log in as a user the who command works but if I use an option like "who -m" I get nothing. Any thoughts on what is causing this problem. (11 Replies)
Hi,
what is the meaning of -n option before the grep command ?
grep command searches for the specified string in the file tmp_crontab.txt
but what does -n mean ?
With Regards (1 Reply)
Hi Friends,
I could see following oracle process in the glance command. i see nothing running in the database although. I tried google it but no success. Another team ,which needs all the processes on the server is complaining. Can someone help me what exactly are these sessions/ how to ... (1 Reply)
I am just learning shell scripting and already I found out I have the bad habit of thinking that it is similar to php or c.
I learned some basics and now encountered this problem:
On shell it is possible to type:
$ date --date="2009-10-10 09:08:34"
Sat Oct 10 09:08:34 CEST 2009
... (2 Replies)
Dear all,
I want to execute fsck command,can i execute fsck command without any option
asking for more confidence.
Thanks and Regards
Monoj Das (1 Reply)
Hi folks,
I totally dislike asking questions in forums but this one eats up to much of my time I need to spend on other topics.
I have a shell-script in which I call a terminal.
I want to invoke bash inside the terminal and print a message inside bash with aid of a here document.
See... (7 Replies)
Discussion started by: bluntroller
7 Replies
LEARN ABOUT DEBIAN
shell-quote
SHELL-QUOTE(1p) User Contributed Perl Documentation SHELL-QUOTE(1p)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$SHELL -c". This doesn't work as intended:
ssh host touch 'hi there' # fails
It creates 2 files, hi and there. Instead, do this:
cmd=`shell-quote touch 'hi there'`
ssh host "$cmd"
This gives you just 1 file, hi there.
process find output
It's not ordinarily possible to process an arbitrary list of files output by find with a shell script. Anything you put in $IFS to
split up the output could legitimately be in a file's name. Here's how you can do it using shell-quote:
eval set -- `find -type f -print0 | xargs -0 shell-quote --`
debug shell scripts
shell-quote is better than echo for debugging shell scripts.
debug() {
[ -z "$debug" ] || shell-quote "debug:" "$@"
}
With echo you can't tell the difference between "debug 'foo bar'" and "debug foo bar", but with shell-quote you can.
save a command for later
shell-quote can be used to build up a shell command to run later. Say you want the user to be able to give you switches for a command
you're going to run. If you don't want the switches to be re-evaluated by the shell (which is usually a good idea, else there are
things the user can't pass through), you can do something like this:
user_switches=
while [ $# != 0 ]
do
case x$1 in
x--pass-through)
[ $# -gt 1 ] || die "need an argument for $1"
user_switches="$user_switches "`shell-quote -- "$2"`
shift;;
# process other switches
esac
shift
done
# later
eval "shell-quote some-command $user_switches my args"
OPTIONS --debug
Turn debugging on.
--help
Show the usage message and die.
--version
Show the version number and exit.
AVAILABILITY
The code is licensed under the GNU GPL. Check http://www.argon.org/~roderick/ or CPAN for updated versions.
AUTHOR
Roderick Schertler <roderick@argon.org>
perl v5.8.4 2005-05-03 SHELL-QUOTE(1p)