I have data that looks like this
aaa!bbb!ccc/ddd/eee
It is not fixed format. I need to parse ddd into a var in order to decide if I want to process that row. If I do I need to put ccc and bbb into vars to process it. I need to do this during a while loop one record at a time. Any... (11 Replies)
Is there a betterway to cut certain columns in everyline based on positions.
Basically, I have a largefile and eachline is of 1000 characters and I need to cut the characters 17-30, 750-775, 776-779, 780-805
while
do
fptr=`cat $tempfile | head -$i | tail -1`
... (4 Replies)
I have a file with the following format
12g data/datasets/cct 8g data/dataset/cct
10 g data/two 5g data/something_different
10g something_different
5g data/two
is there a way to loop through this... (1 Reply)
Hi,
I'm using awk in HP-UX machine which does not support systime(), strftime(). So to get the date time I was using :
seq 1 100000 | awk ' "date +%Y%m%d%H%M%s" | getline curtime; print curtime }'
However the above code gets the date only once, next time it is not updated. For... (2 Replies)
Hello All,
I am new to shell scripting and programming. I am looking for a guide on how I can parse specific information from a plain text file with thousands of lines. Specifically I need to parse an email address from each line. The line looks something like this:... (9 Replies)
Good afternoon!
I have an XML file from which I want to extract only certain elements contained within each line. The problem is that the format of each line is not exactly the same (though similiar). For example, oa_var will be in each line, however, there may be no value or other... (3 Replies)
Hello,
I want to add a letter to the end of a string if it repeats in a column.
so if I have a file like this:
DOG001
DOG0023
DOG004
DOG001
DOG0023
DOG001
the output should look like this:
DOG001-a
DOG0023-a
DOG004
DOG001-b (15 Replies)
I am executing df -mP to see the disk utilization.
I would like to append servername also to each and every line.
df -mP | awk '{ print $1","$2","$3","$4","$5","$6 }'
trying to add something like this
df -mP | awk '{ print $1","$2","$3","$4","$5","$6","$hostname }' ... (1 Reply)
All,
I have a sample text like below.
Key (Header)
Key1
ABC
Key2
ABC
Key3
ABC
ABC
Key4
ABC
Key5
ABC
ABC
ABC
Required Output
Key (Header)
Key1 (2 Replies)
Another project, another bump in the road and another chance to learn. I've been trying to open gzipped files and parse data from them and hit a snag. I have data in gzips with a place followed by an ip or ip range sort of like this:
Some place:x.x.x.x-x.x.x.x
I was able to modify some code... (6 Replies)
Discussion started by: Azrael
6 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)