We have a script that runs in ksh on HP-UX 11.11. It takes three arguments. The last argument can be a filename or wildcard character. For example:
script -s hello -t goodbye '*.d*'
In a case such as this, I would wrap single quotes around the final argument because I dont want the shell to... (4 Replies)
#!/usr/bin/bash
if
then
echo "Not valid arguments entered. Just username should be entered."
else
USER_NAME=$1
FILE_NAME=$USER_NAME.info
UNN=STUDIN\\\\$1
echo $UNN
last STUDIN\\\\$1
last UNN
If I type `last STUDIN\\eip060` it works but if I try to expand it with variable it is... (5 Replies)
Hello -
I have a bash script which does some logging, and I'd like to include the line number of the echo statement that pipes into $LOGGER:
MYPID=$$
MYNAME=`basename $0`
LOGGER="/usr/bin/logger -t $MYNAME($LINENO) -p daemon.error"
...
echo 'this is an entry into the log file' | $LOGGER
... (3 Replies)
I'm in the habit of using the following type of loop structure:
for num in `seq $1 $2`
do
command
doneWhile `seq $1 $2` is not exactly a huge resource hog, I would like to learn a better way. It seems that brace expansion is a good way to go:
for num in {3..10}The problem, though, is... (2 Replies)
The objective of the code below is to create sed script to be later executed. However, it bonks because $ARCHIVENAME expands to a directory specification so the forward slashes cause problems. I can think of a few solutions that would involve redesigning the process, but I'm hoping there might be... (4 Replies)
Hi forum,
in my bash script I've many lines executing commands with redirection to log files.
...
xyz_cmd 2>&1 > $BASENAME.$LINENO
The trailing part of these lines doesn't look nice and I like to put it into a variable.
The (not working) idea is something like that
... (3 Replies)
So, I was bored on the train today, and was thinking of ways to loop through elements of an array. I came up with the following simple script, but it doesn't work as brace expansion doesn't seem to work with variables. Is there something I'm missing, or does the shell just not work like this?
... (4 Replies)
Hello,
I have one variable coming from one file:
abc=$xyz/filename.txt where $xyz is defined in .profile file as say, /usr/dev/src
i am passing abc variable to one perl script as input parameter.
perl 123.pl -s $abc
But inside the perl script execution, the variable $abc is just... (1 Reply)
I want to split one file input.tab into two separate ones, odd lines to input_reads1.txt, even lines to input_reads2.txt for a serial of files with similar name pattern. Also I want to "match" input/output file names to keep consistency of file name:
CSEL_02.0_input.tab
CSEL_03.4_input.tab... (2 Replies)
Hello.
The file /etc/fstab contains
UUID=957c3295-9944-1593-82e2-2b90dede4312 / ext4 noatime,discard,acl,user_xattr 1 1
I fill a variable
SOME_LINE=$( cat /etc/fstab | grep \/\..*ext4 | grep noatime,discard )echo $SOME_LINE... (3 Replies)
Discussion started by: jcdole
3 Replies
LEARN ABOUT CENTOS
shell-quote
SHELL-QUOTE(1) User Contributed Perl Documentation SHELL-QUOTE(1)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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)