This may just be a lack of experience talking, but I always assumed that when possible it was better to use a commands built in abilities rather than to pipe to a bunch of commands. I wrote a (very simple) script a while back that was meant to pull out a certain error code, and report back what... (4 Replies)
Hi ,
I would like to assign command (with pipe) output to a variable. The code is as follows. The goal of the code is to get the last folder folder with a particular name pattern.
myDate=`ls | grep 2009 | tail -1`
echo "myDate=" $myDate
However, in the presence of the pipe, the code... (3 Replies)
Hey all,
I've tried this for quite some time now and haven't figured it out... I was hoping one of you shell scripters could help a newbie out :)
I am trying to take the 1st parameter of my script and use it as the search pattern for my for loop
#!/usr/bin/sh
set -vx
REGEX=$1
... (3 Replies)
Hi,
I am trying to run this command:
ED_CMD="$Access_OPS $ED_Logs_Dir/access | $lgrep -v $Access_Err"
$lgrep $ED_CMD
However, i am getting an error "Failed to open |: Broken pipe at "
My question is how to put a pipe within a variable.
Thanks. John. (4 Replies)
Hi all,
Hope someone can help me out here.
I have this BASH script (see below)
My problem lies with the variable path.
The output of the command find will give me several fields. The 9th field is the path. I want to captured that and the I want to filter this to a specific level.
The... (6 Replies)
<tr><th align=right valign=top>Faulty_Part</th><td align=left valign=top>readhat version 6.0</td></tr> <tr><th align=right valign=top>Submit_Date</th><td align=left valign=top>2011-04-28 02:08:02</td></tr> .......(a long string)
I want to get all the field between "left valign=top>" and "... (2 Replies)
Hey fellas,
I wrote an script which its output is like this:
a 1 T
a 1 T
a 2 A
b 5 G
b 5 G
b 5 G
I wanna print $1 $2 and the total number of $2 value as the third column and after that $3. Sth like this:
a 1 2 T
a 2 1 A
b 5 3 G
I know how to do it with a given input... (4 Replies)
Hello all,
quick question:
is it possible to pass input into AWK BOTH with a pipe AND a file at the same time, something like this:
command .......|awk '.................' FILEIN > fileout
All I read says either one or the other, not both, is it at all possible?
And how would the... (2 Replies)
In the below awk to add a sort by smallest to largest should it be added after the END? Thank you :).
BEGIN {
FS="*"
}
# Read search terms from file1 into 's'
FNR==NR {
s
next
}
{
# Check if $5 matches one of the search terms
for(i in s) {
if($5 ~ i) {
... (4 Replies)
Dear UNIX forum members,
I am using macbook pro 13 (2015 edition) with MAC OS Mojave and am trying to write the shell script where when it is run through terminal it asks for an input (in the code below an input variable is domains) and then that input becomes capital letter or letters which... (3 Replies)
Discussion started by: Aurimas
3 Replies
LEARN ABOUT CENTOS
shell-quote
SHELL-QUOTE(1) User Contributed Perl Documentation SHELL-QUOTE(1)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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)