Very Computer

i=0
for i in $*
do
        if [ $i = "-display" ]
        then
                shift 1
                DISPLAY=$i
        fi
        break
done

The script will be run like this:

$sh abcd.sh abc def -display 166.2.3.45:0 xyz

#! /bin/sh

while :
do
  [ $# -eq 0 ] && break
  case "$1"
  in
    -d*) echo DISPLAY=$2; shift ;;
    *) echo $1 ;;
  esac
  shift
done

#/bin/ksh
flag=0
for i in $*
do
        if [ $flag -eq 1 ];then
                DISPLAY=$i
                break;
        else
          if [ $i = "-display" ]
          then
                flag=1
          fi
        fi
done

Or, better yet, use getopt(1) or the getopts shell builtin.

Joe

#!/bin/sh

flag=0
for i in $*
do
    if [ "$i" = "-display" ]
    then
        flag=1
    elif [ $flag -ne 0 ]
    then
        flag=0
        DISPLAY=$i
    fi
done

echo $DISPLAY      

--
Floyd L. Davidson         <http://www.ptialaska.net/~floyd>

--
Eric Amick
Columbia, MD

        *) echo $1 ;;
      esac
      shift
    done

... which accomplishes shifting the other argument.  But you're right
that another strategy would be to have each case option perform its
own shifting.

        if [ DISPLAY != "" ]
                echo DISPLAY defined
        else
                echo DISPLAY not defined.
        fi

Thanks.

        [ -n "$DISPLAY" ]

To check whether it's set at all (possibly to a null value):

        [ -n "${DISPLAY+x}" ]

These test shell variables, which in the Bourne shell will correspond to
environment variables only if you haven't modified them since your script
started or you've exported them.  In this case it will do what you want since
you're presumably testing whether the variable was set in the environment
passed to your script.

        John
--

Quote:>>>>> qazmlp  writes:
> Is there any function/command in shell, similar to the getenv()
> function in C?  I want to check whether the DISPLAY environment
> variable is existing or not.  I can check like giving as below. But,
> is there any other optimal way?
>    if [ DISPLAY != "" ]
>            echo DISPLAY defined
>    else
>            echo DISPLAY not defined.
>    fi

You don't need getenv() in shell -- just put a $ in front of the
variable.  See the man page for your shell.

--
David Masterson                dmaster AT synopsys DOT com
Sr. R&D Engineer               Synopsys, Inc.
Software Engineering           Sunnyvale, CA