Hi
First apologies if this has been raised before.
I've got the following in a ksh script:
if ]
For some reason this does not work. But if I remove the double square brackets to:
if
This works.
I thought ksh supported the ]. Or is there more to it?
Thanks in advance. (3 Replies)
Hi,
I just came across an interesting shell script syntax like the one below:
] && (trap 'rm -rf ${WORK_DIR}/*.$$; echo "\n\nInterrupted !!\n\n"; exit 4' 1 2 3 15)
Can someone please explain the code snippet above?
The trap command bit is fine but ] && is the hazy part.
Generally we use an... (2 Replies)
Hello,
Can someone please explain to me the following line,
] && break
I do not understand why two test square brackets are used.
Thanks,
Shantanu
---------- Post updated at 03:38 PM ---------- Previous update was at 03:35 PM ----------
And, also why there's a $ before (echo $c |... (5 Replies)
hi guys,
i'm writing a script that looks for a unquie id in a file and replaces a string between two square brackets on the same line as the unquie id:
.......
.......
0001 zz 43242 replace this text] name
0002 sd 65466 UK] country
.......
.......
how can i find line with id 0001... (6 Replies)
Hi All,
I have a text file which looks like this:
computer programming
systems engineering
I want to get rid of these square brackets and also the text that is inside these brackets. So that my final text file looks like this:
computer programming
systems engineering
I am using... (3 Replies)
Hi frieds, I don't understand the difference between single square bracket and double square brackets in a IF condition.
Ex.
if ;
then
RETURNJOB=1
else
RETURNJOB=0
fi
It run, but this
if ];
then
RETURNJOB=1
else
RETURNJOB=0
fi (4 Replies)
Hello all,
I have the following problem:
$ cat infile
this is spam and i need this too
this is spam and i need this too
$ perl -nwe '$_ =~ /]+ \]+)\]\]*\]? (\+)$/; print "$1 - $2\n";' infile
i need this - too
i need this - and i need this too
I am not sure how many occurences of... (13 Replies)
Hi All,
Hope you all are doing good. Yesterday in my project i came across a scenario which i can not guess why it was working in one region and why it was not in another region. Please find my issue below.
I am using AIX version 6.0 of UNIX in my project, in shell scripting i have the... (1 Reply)
Discussion started by: mad man
1 Replies
LEARN ABOUT CENTOS
shell-quote
SHELL-QUOTE(1) User Contributed Perl Documentation SHELL-QUOTE(1)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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)