but you can also read there (and many other sources):
Quote:
The eval command can be risky, and normally should be avoided when there exists a reasonable alternative. An eval $COMMANDS executes the contents of COMMANDS, which may contain such unpleasant surprises as rm -rf *. Running an eval on unfamiliar code written by persons unknown is living dangerously.
Greetings,
I am wrapping the monitoring commands like vmstat, sar, iostat and call via arguments
I want ./unix_stats.sh -v vmstat -p <SEC> -d <Duration>
to give vmstat values, and similarly iostat etc.,.
Also if I give ./unix_stats.sh -v vmstat -i iostat -p <SEC> -d <Duration> should give... (4 Replies)
Hi All,
My query is as below:
Am basically writing a parser script.
My input file has got some variables which are populated by the calling program.
callig program:
fun1("cat","dog","cow")
input.*
argument first
argument second
I want to write a script that should give me... (4 Replies)
Hi All,
i have script like below..
echo "1) first option"
echo ""
echo "2) second option"
echo ""
echo "*) please enter the correct option"
read select
case $select in
1) echo "first option selected"
;;
2) echo "second option selected"
;;
*) echo "please enter the correct... (4 Replies)
Hi all
I have got a file digits.data containing the following data
1 3 4
2 4 9
7 3 1
7 3 10
I am writing a script that will pass an argument from C-shell to nawk command. But it seems the values in the nawk comman does not get set. the program does not print no values out. Here is the... (2 Replies)
Hello all,
New to C and I'm trying to write a program which can run a unix command. Would like to have the option of giving the user the ability to enter arguments e.g for "ls" be able to run "ls -l".
I would appreciate any help.
Thanks
#include <stdio.h>
#include <unistd.h>
#include... (3 Replies)
Hi all:
I'm trying to pass an argument to a command but it's being difficult.
#!/bin/bash
set -xv
if ; then
echo "More than 1 argument entered"
echo "Please enter a month using 3 character names, ie, Jan, Mar, Apr, Dec" && exit 1
fi
if ; then
echo "Please enter a month using... (2 Replies)
Hi,
I have a script that is scheduled with cron and runs every night. The cron part looks like this:
00 20 * * 0,1,2,3,4,5,6 /usr/local/bin/BACKUP TBTARM HOT DELETE
My issue is with the 3rd parameter. Somewhere in the script, i want to tell the script to delete some files if the 3rd... (7 Replies)
How to pass the alphabet character as a argument in case and in if block?
ex:
c=$1
if a-z ]]
then
echo "alphabet"
case $1 in
a-z) echo "the value is a alphabet"
edit by bakunin: please use CODE-tags. We REALLY mean it. (9 Replies)
Hi,
I have a .pcap.gz file and I would like to initially gzip it and then pass the resulting .pcap filename as an argument to a piped tool; the right-hand tool is not standardized linux tool but a custom one that strictly requires the string name of a given .pcap file in order for the pcap file... (2 Replies)
I am trying to pass a second argument like so:
if ] then
export ARG2=$2
else
message "Second argument not specified: USAGE - $PROGRAM_NAME ARG1 ARG2"
checkerror -e 2 -m "Please specify if it is a history or weekly (H or W) extract in the 2nd argument"
fi
however, it always goes... (4 Replies)
Discussion started by: MIA651
4 Replies
LEARN ABOUT CENTOS
shell-quote
SHELL-QUOTE(1) User Contributed Perl Documentation SHELL-QUOTE(1)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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 v5.16.3 2010-06-11 SHELL-QUOTE(1)