could you please explain the below code
need to know the significance of 2, will it look for 2ns field with delimiter
In sed, s is the substitute command. In this case, it is telling sed to change a space to a space followed by a double quote, and the 2 says to make the change to the 2nd occurrence of space on the input line.
This User Gave Thanks to Don Cragun For This Post:
Hi,
I need some advise on treating non printable chars over ascii value 126
Case 1 :
On some fields in the text , I need to retiain then 'as-is' and load to a database.I understand it also depends on database codepage.
but i just wanna know how do i ensure it do not change while loading... (1 Reply)
Hi,
I'm looking for a script that receives the traps from a windows machine and treate them. For exemple just write a line in a file on UNIX server. Can you help me ?
Thank you. (2 Replies)
I have a file list.txt which has a list of file names with spaces between the file names like
/emptydir/file 1
how do i browse through the list.txt displaying the filenames. Almost all the file names in list.txt have space between them.This file list.txt is formed by using the find statement to... (5 Replies)
Is there a way to treat a string as date and compare it to the current date?
lets assum inpu lik
$ cat myfile
Name Last login
**************************
Sara 2/13/2012
kalpeer 2/15/2012
ygemici 2/14/2012
we want to display the name who logged in during the last #... (4 Replies)
Hi, I need to display the last column value in the below o/p.
sam2 PS 03/10/11 0 441
Unable to get o/p with this awk code
awk -F"+" '{ print $4 }' pwdchk.txt
I need to display 441(in this eg.) and also accept it as a variable to treat it with if condition and take a decision.... (1 Reply)
I'm trying to write a bash script to perform basic arithmetic operations but I want to run a comparison on the arguments first to check that they're a number greater than zero.
I want an error to pop up if the arguments args aren't >= 0 so I have:
if ! ]; then
echo "bad number: $1"
fi
... (14 Replies)
Hi, awk seem to be acting differently in Unix and Linux when it comes to formatting. This is making it difficult to migrate scripts.
for example:
UNIX:
echo "123" |awk '{printf ("%05s\n" ,$1)}'
00123
echo "123" |awk '{printf ("%05d\n" ,$1)}'
00123
echo "S12" |awk '{printf ("%05s\n"... (9 Replies)
Greetings Experts,
We are migrating from AIX to RHEL Linux. I have created a script to verify and report the NULLs and SPACEs in the key columns and duplicates on key combination of "|" delimited set of big files. Following is the code that was successfully running in AIX.
awk -F "|" 'BEGIN {... (5 Replies)
Hello there
I'd like to make a copy of 2nd column and have it printed in place of column 1. Remaining columns are needed as it.
test data:
ProbeSet GeneSymbol X22565285 X22566285
ILMN_1050008 MYOCD 6.577 7.395
ILMN_1050014 GPRC6A 6.595 6.668
ILMN_1050017 ... (2 Replies)
Discussion started by: genome
2 Replies
LEARN ABOUT CENTOS
shell-quote
SHELL-QUOTE(1) User Contributed Perl Documentation SHELL-QUOTE(1)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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)