07-23-2010
10 More Discussions You Might Find Interesting
1. Programming
I am learning output the data to a file using "ofstream". I need to read data from a file and output the result to the other file in 2 different ways. To do that I have to provoke two functions, and they have to output the result to the same text file. My problem is: they are correct on the screen... (2 Replies)
Discussion started by: HOUSCOUS
2 Replies
2. UNIX for Dummies Questions & Answers
Hi,
I am triying to make sure that there exists only one file with the pattern abc* in path /path/. This directory is having many huge files. If there is only one file then I have to take its complete name only to use furter in my script.
I am planning to do like this:
if ; then... (2 Replies)
Discussion started by: new_learner
2 Replies
3. UNIX for Dummies Questions & Answers
Hi folks,
Please advise which command/command line shall I run;
1) to display the command and its output on console
2) simultaneous to save the command and its output on a file
I tried tee command as follows;
$ ps aux | grep mysql | tee /path/to/output.txt
It displayed the... (7 Replies)
Discussion started by: satimis
7 Replies
4. UNIX for Advanced & Expert Users
Hi,
I read the ipcs man page and am still very confused.
Basically, I just want to know whether the output from the ipcs command below means these are the current "TOTAL" memory usage in bytes on the server? Is this correct?
Thanks in advance.
ipcs command output below:
# ipcs... (2 Replies)
Discussion started by: newbie_01
2 Replies
5. Shell Programming and Scripting
Hi
I want to write a script, help me to monitor command output.
This script like Linux "watch" command.
Below is my script:
# cat watch.sh
#!/bin/bash
while true
do
clear
echo "command: $*"
( $* )
sleep 2
done
Then I run this script below (2 Replies)
Discussion started by: nnnnnnine
2 Replies
6. UNIX for Dummies Questions & Answers
HI Guys,
I hope you are well. I am trying to write a script that gets executed every time i open a shell (cshell). I have two questions about that
1) I need to enter these commands
$ echo $DISPLAY
$ setenv $DISPLAY output_of_echo_$display_command
How can i write a... (2 Replies)
Discussion started by: kaaliakahn
2 Replies
7. Shell Programming and Scripting
Hi Experts,
I am very much new to linux scripting, I am currently working on reducing my manual work and hence writing a script to automate few task.
I am running below command to snmpwalk the router..
snmpwalk -v 3 -u WANDL_SU -a MD5 -A vfipmpls -x DES -X VfIpMpLs -l authPriv... (19 Replies)
Discussion started by: Hanumant.madane
19 Replies
8. Red Hat
I ran the following command.
cat abc.c > abc.c
I got message the following message from command cat:
cat: abc.c : input file is same as the output file
How the command came to know of the destination file name as the command is sending output to standard file. (3 Replies)
Discussion started by: ravisingh
3 Replies
9. UNIX for Dummies Questions & Answers
Hi Guys,
I like to output every command executed in the script to a file.
I have tried set -x which does the same.
But it is not giving the logs of the child script which is being called from my script.
Is there any parameters in the Set command or someother way where i can see the log... (2 Replies)
Discussion started by: mac4rfree
2 Replies
10. Shell Programming and Scripting
I am using UNIX to create a script on our system. I have setup my commands to append their output to an outage file. However, some of the commands return no output and so I would like something to take their place.
What I need
The following command is placed at the prompt:
TICLI... (4 Replies)
Discussion started by: jbrass
4 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)