Fileglob (things like '*.txt') is not an argument. The shell expands it to all files matching a pattern and then all these files become arguments to a command.
Look at:
and you can see what really echo gets as arguments.
And how avoid? In your example - just use "cp". In more realistic example - call a function with necessary arguments at the front of argument list and work with optional arguments using standard shell technique - $@ array, for loop, shift builtin.
I have written a script which does a following functions:-
1) Check a area if it is mounted or not
2) If the area is not mounted it will prompt the user to mount the are.
3) Once the area is mounted and the option is given as Y or y
the script continues...
My question is will the below... (2 Replies)
hi,
how can i can pass the value of unixformat to date/time? and how can i retrieve the day/month/year from a date?
thanks a lot for your help
ps:i using php (1 Reply)
I use FreeBSD,and use signal,like follows:
signal(SIGHUP,sig_hup);
signal(SIGIO,sig_io);
when I run call following code,it can run,but I find a puzzled question,it should print some information,such as printf("execute main()") will print execute main(),but in fact,printf fuction print... (2 Replies)
I am trying to copy a folder which contains a list of C executables.
It takes 2 mins for completion,where as the entire script takes only 3 more minutes for other process.
Is there a way to copy the folder faster so that the performance of the script will improve? (2 Replies)
Hello again,
Am having an issue now with getting a simple grep command to work within a function..
The function is as below...
function findRecord() {
output=grep "001" recordDatabase
echo $output
}
At the moment the "001"... (3 Replies)
Hi All,
I am new to Unix , there i am facing one problem with sleep command. that is ..
in while loop i have defined sleep function ..
my condition is like this
while #i knew this is infinite loop
do
sleep 200
echo "hello "
done.
this condition will never become .. true... (3 Replies)
Hello, and here's my problem:
I can't get my function to do what I want. When I call my function get_from_A_to_F I give it an argument $remainder. I want my function to substitute a number higher than 9 to a specific letter. If the argument is equal to 10 than it should change it to "A".... (8 Replies)
I am new to this forum. I have a script which randomly throws error.Following are steps followed in this script:
Generate Term file
Remove previous term and rpt files from utility directory.
copy term file to utility directory
call sql to generate rpt file using term file as input
copy the... (4 Replies)
Hi i have a script that check pings and i use flock to so the script wont run
multipul times :
its not the whole script but this is the idea :
(
flock -x -w 3 200 || exit 1
/usr/sbin/fping -c$count -i$interval -a $hosts > $FILE1 2>&1
) 200>/var/lock/.myscript.exclusivelock
now i... (4 Replies)
Hi guys and gals...
I am writing a piece of code that is dash compliant and came across this error.
I have put it in the OSX section as that is what I am using.
I have no idea what the 'dash' version is but was installed about 6 months ago.
MBP, OSX 10.12.6, default terminal running dash on... (4 Replies)
Discussion started by: wisecracker
4 Replies
LEARN ABOUT CENTOS
shell-quote
SHELL-QUOTE(1) User Contributed Perl Documentation SHELL-QUOTE(1)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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)