I am trying to create a shell (ksh) which has two "read" commands, one which reads a line from a file and another which is inside a loop that reads user input from a keyboard. However, the "read" command inside the loop uses the input from the file and it does not get the user input from keyboard.... (3 Replies)
Hello all,
How can i have a user input that reads like this:
echo -n "Please enter a & b:" 10 20
read a
read b
echo $a
echo $b
10
20
right now i have divided it into two echos, like
echo -n "a: "
echo -n "b: " (1 Reply)
I'm trying to set up a script that takes user input and validates that the user input was entered correctly.
So far I have this:
while :
do
echo "Please enter your name."
read NAME
if
then
echo "You have not entered a name."
echo... (13 Replies)
If I want all user input to start with " : " if not display error
or what I asking is how to do if statement that control a first letter of string that we want to start with. and not worry about the rest
Thank (1 Reply)
Hi,
echo "Enter file name of input file list along with absolute path : "
read inputFileList
if
then
for string in `cat inputFileList`
do
echo $string
done
else
echo " file does not exist"
fi
From the above code, if the user enters a invalid file... (1 Reply)
i have a script which takes input from user, if user gives either Y/y then it should continue, else it should quit by displaying user cancelled.
#!/bin/sh
echo " Enter your choice to continue y/Y OR n/N to quit "
read A
if
then
echo " user requested to continue "
##some commands... (7 Replies)
$Input_filename=$ARGV;
if (!-d $Input_filename && ! -e $Input_filename)
{
print "USAGE: Please enter '$ABCD/def/dsed.txt' as an arguement \n";
exit;
}
1. Input Is suppose to be something like "$ABCD/def/dsed.txt".
if the input is wrong the script should throw an ERROR message.... (2 Replies)
Why does removing "rhgb quiet" from the kernel boot parameters control whether or not the commands I enter are displayed in single user mode ?
For instance, if I do not remove "rhgb quiet", when I am in single user mode, whatever command I type will not be displayed on the screen.
The... (0 Replies)
I am trying to allow a user to enter in text and then store that text in a variable $gene to run in an awk command in which those values are used to run some calculations. I am getting syntax errors however, when I try. Thank you :).
The awk runs great if it is a pre-defined file that is used,... (7 Replies)
Discussion started by: cmccabe
7 Replies
LEARN ABOUT DEBIAN
shell-quote
SHELL-QUOTE(1p) User Contributed Perl Documentation SHELL-QUOTE(1p)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$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 v5.8.4 2005-05-03 SHELL-QUOTE(1p)