1. The -n operator takes only one operand. If $a contains any IFS whitespace, the unquoted command substitution will result in more than one word and a syntax error. Since we don't know for certain anything about the range of possible values for $a, this unquoted version might be buggy. It also wouldn't hurt to double quote "$a" within the command substitution.
2. You could simplify your approach to use grep's exit status directly:
Regards,
Alister
Alister ,
I tried the above code but its showing another error
Here is the code I used
Hi,
I would like to know what exactly "-a" option does in the if conditional statement. I am sure, it is not doing the logical AND (&&) operation since it appears before the file.
#!/bin/ksh
for file in $* ; do
if ] ; then
basefile=`basename $file`
cp $file... (2 Replies)
I am attempting to create a shell script with the following capaciblities:
1. Listed options to choice from
2. Use to perform awk statements
3. Print a report with the awk results
My questions are
1. How do I select more than one file for option #5 and #6
2. How to I create an... (11 Replies)
Hi,
Please tell me how to use insert option of sed in a shell script on Solaris/AIX plateform.
For example I need to insert few lines on top of every file whose name starts with say "SOL_DEL".
Thanx. (2 Replies)
To find all the files in your home directory that have been edited in some way since the last tar file, use this command:
find . -newer backup.tar.gz
Is anyone familiar with an older solution?
looking to identify files older then 15mins across several directories.
thanks,
manny (2 Replies)
Hello everyone. I am new to shell scripting and i am required to create a shell script, the purpose of which i will explain below.
I am on a solaris server btw.
Before delving into the requirements, i will give youse an overview of what is currently in place and its purpose.
... (2 Replies)
The script below fails with the following error messages:
gzip: invalid option -- 'w'
Try `gzip --help' for more information.
mysqldump: Got errno 32 on write
cp: invalid option -- 'w'
Try `cp --help' for more information.
rm: invalid option -- 'w'
Try `rm --help' for more information.
... (1 Reply)
Hi All,
I am trying to execute the following tar command with two --exclude options to suppress extract of the two directories specified.
Do I need to single quote the directory paths ??
Many thanks for your help.
The relevant code excerpt from the script is:
cd /var/www/${SITE}
... (7 Replies)
HI Guys,
My Script abc.sh
1) Checks
2) CA Scipt
3) CIA Script
0) Exit
Enter Choice :
Now if i select choice 2 then after finshed choice 2 wait for 40 min and run choice 3
what i can write in CA Scipt option:
if
then
My Code :
... (3 Replies)
Hello,
I want to design a script that will call an existing menu script and select options one by one and redirict the out put to a file.
For example;-
In the script MENU.sh there are 10 options i want to design a script MENU2.sh that will select option 2 3 4 6 7 10 and redirict the output... (4 Replies)
Hi All,
I have written a menu driven bash shell script.
Current Output is as below:
-------------------------------------
Main Menu
-------------------------------------
Option 1
Option 2
Option 3
Option 4
Exit
=====================================
Enter your... (3 Replies)
Discussion started by: kiran_j
3 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)