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<<Anchor(faq25)>>
== How can I access positional parameters after $9? ==
Use {{{${10} }}}instead of {{{$10}}}. This works for [[BASH]] and KornShell, but not for older BourneShell implementations. Another way to access arbitrary positional parameters after $9 is to use {{{for}}}, e.g. to get the last parameter:

{{{
    # Bourne
    for last
    do
        : # nothing
    done

    echo "last argument is: $last"
}}}

To get an argument by number, we can use a counter:

{{{
    # Bourne
    n=12 # This is the number of the argument we are interested in
    i=1
    for arg
    do
        if test $i -eq $n
        then
            argn=$arg
            break
        fi
        i=`expr $i + 1`
    done
    echo "argument number $n is: $argn"
}}}

This has the advantage of not "consuming" the arguments. If this is no problem, the {{{shift}}} command discards the first positional arguments:

{{{
    shift 11
    echo "the 12th argument is: $1"
}}}

In addition, bash and ksh93 treat the set of positional parameters as an [[BashFAQ/005|array]], and you may use [[BashFAQ/073|parameter expansion]] syntax to address those elements in a variety of ways:

{{{
    # Bash, ksh93
    for x in "${@:(-2)}" # iterate over the last 2 parameters
    for y in "${@:2}" # iterate over all parameters starting at $2
                            # which may be useful if we don't want to shift
}}}

Although direct access to any positional argument is possible this way, it's seldom needed. The common alternative is to use {{{getopts}}} to process options (e.g. "-l", or "-o filename"), and then use either {{{for}}} or {{{while}}} to process all the remaining arguments in turn. An explanation of how to process command line arguments is available in [[BashFAQ/035|FAQ #35]], and another is found at http://www.shelldorado.com/goodcoding/cmdargs.html

----
CategoryShell
My name is Tomoko and I am studying Gender and Women's Studies and Occupational Therapy at Augusta / Italy.<<BR>>
<<BR>>
Also visit my web-site - [[http://host-a.net/u/danielross/Many_Approaches_to_Discover_Help_for_Alcoholism.pdf|How To Quit Drinking]]

My name is Tomoko and I am studying Gender and Women's Studies and Occupational Therapy at Augusta / Italy.

Also visit my web-site - How To Quit Drinking

BashFAQ/025 (last edited 2014-04-24 10:02:07 by pgas)