I have a little code block (executing on AIX 7.1) that I cannot understand why the NOTFREE=0 does not appear to be assigned even though it goes through that block. This causes a unary operator issue.
As others have stated the while loop is run in a subshell and variable assignments are lost the general accepted solution is to use Process Substitution eg:
This User Gave Thanks to Chubler_XL For This Post:
Hi
I am doing a script like
if
then
echo "table name dosent exist"
exit
fi
the problem is if $table_name is null then i am getting the error
Please help me
Thanks in advance (2 Replies)
hi
i am trying to compare a value with value 50. but i am getting
"
I am using
if
then
echo "------------"
fi
please help
thanks in advance
Satya (2 Replies)
Im trying to fix my /etc/weekly that rotates various logs however it does them no matter what filesize they are and i want them to only do it if there file size exceeds 2M or something. So I'm playing with a script to get the filesize using a ls -l command which works and puts the value into a... (3 Replies)
Hello all, :confused:
I am not getting this error.
Pls help me.
./construct_operon.sh: line 5:
#!/bin/bash
# Construct Operons using gene pairs.
rm -rf operons_result
lines=`awk 'END {print NR}' ecoli_operons`
while ;
do
head -1 ecoli_operons | awk '{print $1"\n"$2}' > pattern
... (5 Replies)
Why am I getting this error.... #!/bin/sh
# iOS-Ad-Remover
# Marshall Ford @ marshallbford@gmail.com
# This project is hosted @ http://ios-ad-
# remover.sourceforge.net
# Under the GNU GPL open source license
clear
echo
if ; then echo "You need to be root to run this script."; exit 0; #... (24 Replies)
i=0
while
Shell script reports an error "unary operator expected" pointing the above line.
$i by default is 0 and holds integer value and $buf is also holding integer value.
Please can some one let me know what is missing.
Thanks. (1 Reply)
Hiya all,
Why do I get a :unary operator expected when I try to put a condition statement in my shell script (sh) like so and how to fix?
if ; then
echo "say hello"
else
echo "don't say hello"
fi
? It seems if the script receives an argument it works but if I don't put an... (4 Replies)
Hi
I have problem with my script.
I dont now why but i don't change anything and script stop working.
this is my code:
#!/bin/sh
for i in `ps -A | grep pocron.sh | grep -v grep | awk '{print $2}'`
do
COUNT=$((COUNT+1))
done
ostatnie_wykonanie=`cat porader.log`... (1 Reply)
In all my Googling, this usually happens when someone is comparing a variable, and that variable is unset. That doesn't appear to be the case for me...
#!/bin/bash -x
while read line
do
f=$(echo $line | tr -s ' ' | cut -d' ' -f 3)
echo $f
if
then
echo "This... (2 Replies)
Discussion started by: jnojr
2 Replies
LEARN ABOUT CENTOS
shell-quote
SHELL-QUOTE(1) User Contributed Perl Documentation SHELL-QUOTE(1)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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)