Why "$TBS" ? If TBS is empty, you get error if not "". Usually it's safety to use always " " with variable. String length 0 / null string.
This is one of the few instances where it is never necessary to quote the variable; case is a shell keyword, not a builtin command, so it doesn't parse the line as if it were a command.
Even if $TBS could be empty, there's no need to quote it.
Hi! I'm using
echo $string | grep "" -c
to test in a script if a string is a number and it seems to work. But how can i find, for example, if a string is a four figures number ?
Thanks to all! (2 Replies)
Okay, well this is more or less my first attempt at writing a shell script.
Anyways, here's my code:
cd ${PATH}
if
then
rm ${FILE}
./anotherScript
else
exit 1
fi
exit 1
Anyways, it's a pretty simple script that is supposed to search for the... (4 Replies)
This is the code:
while test 1 -eq 1
do
read a
$a
if test $a = stop
then
break
fi
done
I read a command on every loop an execute it.
I check if the string equals the word stop to end the loop,but it say that I gave too many arguments to test.
For example echo hello.
Now the... (1 Reply)
Hello all,
I'm trying to automate an if statement in my Perl script. The script opens an input file for reading, checks each line in the file for a particular substring, and if it finds the substring, writes it to an output file.
There are approximately 200 different input files. Each has... (3 Replies)
Hello,
I am trying to build a test statement but I can't make it work
I want to rearrange some fields, so if my "$cfg" variable contains a string ending with .log (*.log) I want to move it in another field.
Any help will be much appreciated!
Thank you
Shell:sh
if
then
log="${cfg}"... (9 Replies)
Is it possible to test against a varible within a ranges in a if statement.
ex.
if ];then
echo "not in range"
else
echo "number within range"
fi (8 Replies)
Discussion started by: leemalloy
8 Replies
LEARN ABOUT CENTOS
shell-quote
SHELL-QUOTE(1) User Contributed Perl Documentation SHELL-QUOTE(1)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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)