topic Re: Do arrays work in the posix shell? in Operating System - Linux

Do arrays work in the posix shell?

Trever Furnish — Sun, 19 Nov 2006 16:18:04 GMT

Trying to use arrays in the hpux posix shell and either I'm too dumb to interpret the manual page, or the shell's just broken in this respect.

Tell me I'm dumb! :-)

Could someone provide a working example of how to assign three values to one array variable and then reference them?

Re: Do arrays work in the posix shell?

James R. Ferguson — Sun, 19 Nov 2006 16:55:48 GMT

Hi Trever:

Try this:

# cat .sharray
#!/usr/bin/sh
set -A ARY this works for you
echo ${ARY[0]}
echo ${ARY[1]}
exit 0

# ./sharray
this
works

...Regards!

...JRF...

Re: Do arrays work in the posix shell?

Trever Furnish — Sun, 19 Nov 2006 17:10:18 GMT

Thanks, James.

You definitely did exactly what I asked, and now having seen that I realize I was very close in my own attempts, but I had forgotten the numbering started at 0, so when I was assigning using "set" and then referencing ${a[1]}, the shell was telling the truth when it claimed the variable wasn't set. D'OH! :-)

Re: Do arrays work in the posix shell?

Bill Hassell — Sun, 19 Nov 2006 19:34:18 GMT

The set -A directive is quite nice as it can not only declare the array but assign some of all the values you need at one time. And the elements may be strings:

set -A REASON \
"exceeded password lifetime" \
"exceeded last login time" \
"exceeded absolute account lifetime" \
"exceeded unsuccessful login attempts" \
"password required and a null password" \
"administrator lock" \
"password is a * (asterisk)"

You can display all the defined elements with @ like this:

echo "${REASON[@]}"

or show the elements by number:

for N in 0 1 2 3 4 5 6
do
echo "$N = \"${REASON[$N]}\""
done

Re: Do arrays work in the posix shell?

Peter Nikitka — Mon, 20 Nov 2006 05:04:30 GMT

Hi,

to make Bill's solution a little more general, you can loop through an array without explicitly naming the indices:
Change
>>
for N in 0 1 2 3 4 5 6
do
echo "$N = \"${REASON[$N]}\""
done
<<

To

typeset -i N=-1
while [ N+=1 -lt ${#REASON[*]} ]
do print $N = \"${REASON[N]\"
done

mfG Peter

Re: Do arrays work in the posix shell?

Trever Furnish — Mon, 20 Nov 2006 08:17:56 GMT

Thanks, guys. I assigned 5 points each for the additional info, since James had already scored the 10.