How to get the user input recursively until the user provides valid input Post: 302632383

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Getting user input

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....

2. Shell Programming and Scripting

Reading input from user

how do we read input from a user e.g i want to ask a user to enter 6 sets of numbers how do i control information from the user? i have this....... #!/bin/bash echo "Please enter six numbers" read number echo $number >> file1 but this stops after the first number..how can i...

3. Shell Programming and Scripting

tcsh and user input

Here is my script: echo "var 1:" read varone echo "$varone" When I run in via ksh the script runs successfully. However when I run it via tcsh I get "varone: Undefine variable" Does the name command not work with tcsh or do I need some additional modification? Is there a way to get...

4. Shell Programming and Scripting

Valid input compared with input

Hi everyone, I cant seem to figure this out for the life of me. Basically, I have two arrays.. sub init { use Getopt::Long; use Data::Dumper; my @selections = (); my @valid_options = ( "vaild1", "valid2" ); GetOptions( "input=s" =>...

5. Shell Programming and Scripting

user input in perl?

Please tell me how to write a perl script that asks the user to enter words and that passes them to a variable. In bash, the "read" command would achieve such user interaction. #!/bin/bash read -p "Enter files: " vFiles However, I am looking for perl version of something equivalent...

6. Shell Programming and Scripting

Script interacts with user , based on user input it operates

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. Shell Programming and Scripting

How to check the user input to be valid using shell script?

How to check the user input to be valid using shell script? The valid input is in the format like as follows. 1. It can only have r,w,x or a hyphen and nothing else. 2. ensure the r, w, x are in the correct order. for example: rwxr-xr-x is a valid format. Thanks

8. UNIX for Dummies Questions & Answers

Clumsy user input

The (longer) script that I am working on does something like this: #!/bin/bash while true do clear sleep 1 shuf -i1-2 -n1 sleep .1 clear echo "Press 1 if you saw a 1. Press 2 if you saw a 2." read -s -n1 RESPONSE done If the user accidentally presses two...

9. Shell Programming and Scripting

User input and run awk using the input

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,...

10. Shell Programming and Scripting

Controlling user input

I'm trying to use a bash script for a psych experiment that involves listening to sound files and responding. If I have something like the code below, how can I make sure that a key press is assigned to RESPONSE only after the second echo statement? for i in 1 2 3; do echo "Ready?" sleep 2 ...

LEARN ABOUT DEBIAN

empty-page

EMPTY-PAGE(1)							 ExactImage Manual						     EMPTY-PAGE(1)

NAME

       empty-page - empty page detector of the ExactImage toolkit

SYNOPSIS

       empty-page [option...] {-i | --input} input-file

       empty-page {-h | --help}

DESCRIPTION

       ExactImage is a fast C++ image processing library. Unlike many other library frameworks it allows operation in several color spaces and bit
       depths natively, resulting in low memory and computational requirements.

       empty-page counts dark pixels of a black and white image and decides with a threshold whether the page is most probably empty, and thus can
       be removed from the image processing stream.

OPTIONS

       -i file, --input file
	   Read image from the specified file.

       -m n, --margin n
	   Set width of border margin to skip. For speed reasons, the margin has to be a multiple of 8. The default is 16.

       -p x, --percentage x
	   Set fraction of permissible dark pixels. The default is 0.05 (5%).

       -h, --help
	   Display help text and exit.

EXAMPLES

	   $ empty-page -i test.tif
	   The image has 75461 dark pixels from a total of 1060992 (7.11231%).
	   non-empty

EXIT STATUS

       The exit status is 0 if the image is mostly white, 1 otherwise.

SEE ALSO

       exactimage(7)

AUTHORS

       Jakub Wilk <jwilk@debian.org>
	   Wrote this manual page for the Debian system.

       http://www.exactcode.de/site/open_source/exactimage/
	   This manual page incorporates texts found on the ExactImage homepage.

COPYRIGHT

       This manual page was written for the Debian system (and may be used by others).

       Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License, Version 2 or (at
       your option) any later version published by the Free Software Foundation.

       On Debian systems, the complete text of the GNU General Public License can be found in /usr/share/common-licenses/GPL-2.

empty-page							    09/09/2013							     EMPTY-PAGE(1)