[2 days left] What’s wrong with your cloud strategy? Learn why multicloud solutions matter with Nimble Storage.Register Now

x
?
Solved

Bash - check the first letter of a var

Posted on 2007-04-06
4
Medium Priority
?
231 Views
Last Modified: 2010-05-18
while [ -z $cnickname ] || echo ${cnickname:0:1} | grep [:digit:];
do
if echo ${cnickname:0:1} | grep [:digit:]; then
something

When i execute this it says: Syntax error: Bad substitution, any ideea whats wrong ?
The script should take the virst letter of $cnickname and see if its a digit, and if it is do something
0
Comment
Question by:rares_dumitrescu
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
4 Comments
 
LVL 84

Expert Comment

by:ozo
ID: 18863049
Are you sure you are running it in bash and not in sh?
0
 

Author Comment

by:rares_dumitrescu
ID: 18863093
you're right i was using /bin/sh, i changed it to #!/usr/local/bin/bash .. now it works but the if, or while does not turn on at echo ${cnickname:0:1} | grep [:digit:]; when i put something like '3blah'
0
 

Author Comment

by:rares_dumitrescu
ID: 18863113
worked
i know i might sound very stupid, but, why didn't it worked with /bin/sh and it works with /bin/bash ?
whats the difference ? (i am making some scripts on a server, like getegg getpsy etc (for irc) using dialog menu)
0
 
LVL 84

Accepted Solution

by:
ozo earned 2000 total points
ID: 18863190
they are different shells, see
man sh
and
man bash
you might try grep '[0-9]'
or
grep '[[:digit:]]'
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Attention: This article will no longer be maintained. If you have any questions, please feel free to mail me. jgh@FreeBSD.org Please see http://www.freebsd.org/doc/en_US.ISO8859-1/articles/freebsd-update-server/ for the updated article. It is avail…
If you have a server on collocation with the super-fast CPU, that doesn't mean that you get it running at full power. Here is a preamble. When doing inventory of Linux servers, that I'm administering, I've found that some of them are running on l…
This video shows how to set up a shell script to accept a positional parameter when called, pass that to a SQL script, accept the output from the statement back and then manipulate it in the Shell.
This demo shows you how to set up the containerized NetScaler CPX with NetScaler Management and Analytics System in a non-routable Mesos/Marathon environment for use with Micro-Services applications.
Suggested Courses

649 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question