I wrote a collection of bash functions years ago and now need to use them again but
I'm getting some error messages when eval tries to expand the variables names.
The problem is ~ is not being expanded. It turns out to be a little tricky to expand ~ but also avoid word separation on the path name (white spaces in you array source filename).
Try:
These 2 Users Gave Thanks to Chubler_XL For This Post:
I have a little script to help me manage a gallery of image files. It makes symbolic links to every file in and below the current directory, placing them in a target directory which is passed to the script as a parameter. Unfortunately, the script pukes when I pass a parameter that contains... (4 Replies)
If have
var='$variable'
how can I expand $variable.
I have tried many thing like duble quotes/braces etc, but nothing worked.
I need the solution ASAP. (2 Replies)
Hi,
The following code finds the line containing fruits in test.txt and replaces instances of apple with banana.
ed -s test.txt <<< $'/fruits/s/apple/banana/g\nw'
What I want to do is put variables in the place of fruits, apple and banana.
I have tried replacing ' with " to get... (2 Replies)
Hi,
I need some direction with the following. The below code is semi-psuedo code which will hopefully make it easier to understand what I am trying to achieve:
for i in `echo ${testarray
}`
do
let c=c+1
eval "first$c=$i"
while... (4 Replies)
Hello,
so i'm making a script, using dynamic variables and trying to expand them. So far it hasn't worked out too well so it seems that I need some help from you, the elite.
Example:
#!/bin/sh
counter=0
until (($counter>5))
counter2=1
until (($counter2>6)); do
if ;... (5 Replies)
Hi Guys,
I have an issue with awk and variables. I have trawled the internet and forums but can't seem to get the exactt syntax I need.
I have tried using awk -v and all sorts of variations but I have hit a brick wall. I have spent a full day on this and am just going round in circles.
... (3 Replies)
My OS is Linux (kernel 4.08.something) and AIX (7100-04-01-1543), the used ksh versions are:
ksh88: Version M-11/16/88f (AIX)
ksh93: Version M 93t+ 2009-05-01 (AIX), Version M 93u (Linux)
When writing a parser for stanza files in ksh i encountered a rather strange behavior. Here is a... (4 Replies)
I pass an argument to bash as run. The first command in green executes as expected, however the second in blue fails as the $run does not expand. I tried to escape the variable with \ thinking the quotes were making the literal translation and also "${run}" but both did not work to expand the... (3 Replies)
Discussion started by: cmccabe
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)