i assume you are going to parse the above string, so once again, the distinct field delimiter you can spot easily, its "&". split on "&" , then go through each item and check is there is anything after the "=" sign, if there is nothing, then its a null string. OR you can split on "=" , and make sure that the next field doesn't start with "&".
I know we can substitute a string using sed but how?
For example: sed 's/(old variable)/(new variable)/ details.dat
Am I suppose to put $old variable or whatever? Because I tried many times, it didnt work by putting $old variable. Am I suppose to enclose it with "" or ''?
Please help (3 Replies)
Hi,
I have a set of files containing strings like I.TEST1_TEST2 or B.ESSA_ESSB for example.
Does somebody know how to substitute these strings whith the same name and an extension "_V1" (ie. I.TEST1_TEST2_V1) using sed command or else ? (3 Replies)
Hi ,
I am stuck up in the below scenario:-
I need to read a file name (eg A.txt) name frm another file (eg B.txt) and then I need to search for a particular expression in A.txt and substitute it with another expression.
How can I use SED inside SHELL Scripting and command prompt as... (2 Replies)
Hi ,
I am stuck up in the below scenario:-
I need to read a file name (eg A.txt) name frm another file (eg B.txt) and then I need to search for a particular expression in A.txt and substitute it with another expression.
How can I use SED inside SHELL Scripting and command prompt as well to... (1 Reply)
Hi guys,
Can u please help me to replace (-) with (/) in a file containing no of records using "sed " command in unix.
thanks in advance.
subhendu (5 Replies)
Hi I am trying to do a text insertion in a text file at a particular line number in a shell script. However its not working.
sed '122i\
> for j in \`echo $MyList\` ; do perl -pi -e\'s#01\/01\/2009#01\/01\/2011#\' $j ; done' $HOME/MyScript.ksh
The Actual line to be inserted at line 122... (5 Replies)
I have a file with some numbers having single quotes around them which I want to remove.
i.e. '923930' -> 23930
If it can be done without using sed thats fine. I have tried with sed but can't think how to replace this pattern on only the numbers (13 Replies)
Hello,
I have two files. File1 is normal txt file and File2 contains list of line numbers.
e.g. File2:
3
6
9
.....
I need to replace a character in File1 in lines (taken from File2). For that I am using a "for" loop:
for i in $(cat File2)
do
sed "$i s/Y/N/" File1
done
but my... (3 Replies)
How can you use sed with a line of code that reads:
67899:Bill:Williams:Maple Dr.:45908600
Let us say we want to replace Maple Dr. with Oak St. (1 Reply)
Hi everyone,
I need very simple sed command to change a parameter in a text file.
I have a line in this text which is like
set xx 0.5
A program reads this file and does some algebraic calculations. So to make a parameter scan I need to change the value of xx. I thought I can do... (7 Replies)
Discussion started by: hayreter
7 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)