mjhjmtu

The following array represented the numbers of disks on each linux machines

Each single array includes the number of disks on a linux machine.

echo $ARRAY_DISK_Quantity[*]
4 4 4 4 2 4 4 4

what is the simple way to identify that all array's values are equal?

Good status:

4 4 4 4 4 4 4 4

Bad status:

4 4 4 4 4 4 2 4

Bad status:

6 6 6 6 6 6 6 6 6 6 2 6 2

bash + GNU sort + GNU grep solution:

if [ "$#array[@]" -gt 0 ] && [ $(printf "%s00" "$array[@]" | 
 LC_ALL=C sort -z -u |
 grep -z -c .) -eq 1 ] ; then
 echo ok
else
 echo bad
fi

English explanation: if unique-sorting the elements of the array results in only one element, then print "ok". Otherwise print "bad".

The array is printed with NUL bytes separating each element, piped into GNU sort (relying on the -z aka --zero-terminated and -u aka --unique options), and then into grep (using options -z aka --null-data and -c aka --count) to count the output lines.

Unlike my previous version, I can't use wc here because it requires input lines terminated with a newline...and using sed or tr to convert NULs to newlines after the sort would defeat the purpose of using NUL separators. grep -c makes a reasonable substitute.

Here's the same thing rewritten as a function:

function count_unique() 
 local LC_ALL=C

 if [ "$#" -eq 0 ] ; then 
 echo 0
 else
 echo "$(printf "%s00" "$@" 



ARRAY_DISK_Quantity=(4 4 4 4 2 4 4 4)

if [ "$(count_unique "$ARRAY_DISK_Quantity[@]")" -eq 1 ] ; then
 echo "ok"
else
 echo "bad"
fi

With zsh:

if (($#$(u)ARRAY_DISK_Quantity[@] == 1)); then
 echo OK
else
 echo not OK
fi

Where (u) is a parameter expansion flag to expand unique values. So we're getting a count of the unique values in the array.

Replace == 1 with <= 1 is you want to consider an empty array is OK.

With ksh93, you could sort the array and check that the first element is the same as the last:

set -s -- "$ARRAY_DISK_Quantity[@]"
if [ "$1" = "$@: -1" ]; then
 echo OK
else
 echo not OK
fi

With ksh88 or pdksh/mksh:

set -s -- "$ARRAY_DISK_Quantity[@]"
if eval '[ "$1" = "$'"$#"'" ]'; then
 echo OK
else
 echo not OK
fi

With bash, you'd probably need a loop:

unique_values() return 1
 done
 return 0

if unique_values "$ARRAY_DISK_Quantity[@]"; then
 echo OK
else
 echo not OK
fi

(would work with all the Bourne-like shells with array support (ksh, zsh, bash, yash)).

Note that it returns OK for an empty array. Add a [ "$#" -gt 0 ] || return at the start of the function if you don't want that.

bash + awk soltion:

function get_status() 
 arr=("$@") # get the array passed as argument
 if awk 'v && $1!=v exit 1 v=$1 ' <(printf "%dn" "$arr[@]"); then 
 echo "status: Ok"
 else 
 echo "status: Bad"
 fi

Test case #1:

ARRAY_DISK_Quantity=(4 4 4 4 4 2 4 4)
get_status "$ARRAY_DISK_Quantity[@]"
status: Bad

Test case #2:

ARRAY_DISK_Quantity=(4 4 4 4 4 4 4 4)
get_status "$ARRAY_DISK_Quantity[@]"
status: Ok

I have another bash only solution that should work with strings as well:

isarray.equal () 
 local placeholder="$1"
 local num=0
 while (( $# )); do
 if [[ "$1" != "$placeholder" ]]; then
 num=1
 echo 'Bad' && break
 fi
 shift
 done
 [[ "$num" -ne 1 ]] && echo 'Okay'

Demonstration:

[root@JBSTEST001 ~]# ARRAY_DISK_Quantity=(4 4 4 4 2 4 4 4)
[root@JBSTEST001 ~]# isarray.equal "$ARRAY_DISK_Quantity[@]"
Bad
[root@JBSTEST001 ~]# ARRAY_DISK_Quantity=(4 4 4 4 4 4 4 4)
[root@JBSTEST001 ~]# isarray.equal "$ARRAY_DISK_Quantity[@]"
Okay
[root@JBSTEST001 ~]# ARRAY_DISK_Quantity=(four four four four two four four four)
[root@JBSTEST001 ~]# isarray.equal "$ARRAY_DISK_Quantity[@]"
Bad
[root@JBSTEST001 ~]# ARRAY_DISK_Quantity=(four four four four four four four four)
[root@JBSTEST001 ~]# isarray.equal "$ARRAY_DISK_Quantity[@]"
Okay