Gentle Unix users,
Can someone tell me how I can use a combination of the cat and grep command to display records that are in FileA but missing in FileB.
cat FileA one line at a time and grep to see if it is in fileB. If it is ignore.
If line is not in fileB display the line.
Thanks in... (4 Replies)
I am trying to cat a file and then grep that file for a number. I can do it fine on other files but this particular file will not do anything. I tried running it on an older file from the same device but it is just not working. The file is nothing more than a flat file on a unix box. Here is just a... (3 Replies)
Hi All,
I'd like to do this
cat /etc/passwd
and grep -v on the /etc/shells list
I'd like to find all shell that doesn't exist on the /etc/passwd.
Is there an easy way without doing a egrep -v "/bin/sh|/bin/bash................"?
How do I use a file /etc/shells as my list for... (4 Replies)
Is there a way using grep or cat a file to create a new file based on whether the first 9 positions of each record is less than 399999999?
This is a fixed file format. (3 Replies)
Hi,
I still have the problem with directing information from cat or grep to a variable.
For instance:
XMSG "$(date +%Y_%m_%d)_error_report.txt" "$(cat "$(date +%Y_%m_%d)_error_report.txt")" &Works! The text received by cat is directed to my function.
If it is written like this, my... (2 Replies)
Hello,
i need to search one word (snp1) from many files and copy the content of the columns of this word in new file.
example:
file 1:
SNP BP CHR P
snp1 1 3 0.01
snp2 2 2 0.05
.
.
file 2:
SNP BP CHR P
snp1 1 3 0.06
snp2 2 2 0.3
output... (6 Replies)
Hello
someone told me to use
OS=`awk '{print int($3)}' < /etc/redhat-release`
instead of
OS=cat /etc/redhat-release | `awk '{print int($3)}'`
any idea for the reason ? (5 Replies)
Hi there,
I have 2 files that I am trying to work on.
File 1 contains a reference list of unique subscriber numbers ( 7 million entries in total)
File 2 contains a list of the subscriber numbers and their tariff (15 million entries in total). This file is in the production system and... (12 Replies)
Hi Guys
This is my first post so I am not sure how things go here. I'm sorry if I'm breaking the rule or something. Feel free to correct me about that :)
So as I was saying...
I'd been trying to grep this folder containing 900,000 txt files but seems no luck. I get either "No such file... (6 Replies)
I have a large * delimited text file and need to highlight specific columns on specific lines. The file looks similar to this:
ABC*01*00*01*00000 000000 *00000 000000 *35*0*0*0*0*20000*0*0*1*0000*00*4*0*3*0*0*1*0* *35*0000*001*4*1OT2*0148*0*0*0*0*0*0*6A7801B0**TEST1... (1 Reply)
Discussion started by: say170
1 Replies
LEARN ABOUT CENTOS
shell-quote
SHELL-QUOTE(1) User Contributed Perl Documentation SHELL-QUOTE(1)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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)