This will work for files which are small enough to fit into memory. The downside is, that if anything goes wrong (power loss, reboot, process aborted, ...) your data will be irrevocably destroyed. You sure do not want to use this hack on critical data just to save a few GB of (temporary) diskspace.
That won't work even when there's just a single byte in the file, if the shell first creates the sed portion of the pipeline. There are no guarantees on which component of a pipeline will be created first.
Dear friends,
please tell me how to find the files which are existing in the current directory, but it sholud not search in the sub directories..
it is like this,
current directory contains
file1, file2, file3, dir1, dir2
and dir1 conatins
file4, file5
and dir2 contains
file6,... (9 Replies)
Hi Guys,
Req your help in searching and replacing the word that comes after equals(=) symbol
I would like to replace the sting in bold with a string in variable.
d=ABCDF8C44C22
# grep -i NIM_MASTERID ${_NIMINFO}
export NIM_MASTERID=00CDF8C44C00
I'm looking to replace any word that... (4 Replies)
Hi,
I have line in input file as below:
3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL
My expected output for line in the file must be :
"1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL"
Can someone... (7 Replies)
Hi all,
I have this text file containing 9 columns separated by space. The 8th columns contains the numbers.
C1 C2 C3 C4 C5 C6 C7 C8 C9
er rt yt gh iu nk il 0.07 xs
yt lr ty bg iu zk nh 0,0005 lt
...etc.
I want to replace the comma with full stop only in 8th coloumn.
the output... (8 Replies)
I want to list all files/lines which except those which contain the pattern ' /proc/' OR ' /sys/' (mind the leading blank).
In a first approach I coded:
find / -exec ls -ld {} | grep -v ' /proc/| /sys/' \; > /tmp/list.txt
But this doesn't work. I got an error (under Ubuntu):
grep:... (5 Replies)
Hi,
Below line selects only dates comes after than today.
I need to change below line as "more or equal":
awk -F\## -v d=$(date +%Y%m%d) '{if($NF>d)print}' /usr/batch/pill.txt > /usr/batch/pill_in_use.txt
When we change the code, it will print today's date and following dates only.
... (2 Replies)
How to use "mailx" command to do e-mail reading the input file containing email address, where column 1 has name and column 2 containing “To” e-mail address
and column 3 contains “cc” e-mail address to include with same email.
Sample input file, email.txt
Below is an sample code where... (2 Replies)
Dear Ladies & Gents,
I have a requirement to delete all the log files in /var/log/test directory that are older than 10 days and their first line begin with "MSH" or "<?xml" or "FHS". I've put together the following BASH script, but it's erroring out:
for filename in $(find /var/log/test... (2 Replies)
I'm trying to find out what happened to the rogue game that apt-get told me it installed, so I thought I would find the file. I went to the root and entered:
find -name "rog*.*"
I get a large number of lines saying my access is denied in various directories. I figure I'll practice my Unix... (14 Replies)
Discussion started by: arghvark
14 Replies
LEARN ABOUT DEBIAN
shell-quote
SHELL-QUOTE(1p) User Contributed Perl Documentation SHELL-QUOTE(1p)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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 v5.8.4 2005-05-03 SHELL-QUOTE(1p)