Using:
set -o nounset
Having an indexed array like:
myArray=( "red" "black" "blue" )
What is the shortest way to check if element 1 is set?
I sometimes use the following:
test "${#myArray[#]}" -gt "1" && echo "1 exists" || echo "1 doesn't exist"
I would like to know if there's a preferred one.
How to deal with non-consecutive indexes?
myArray=()
myArray[12]="red"
myArray[51]="black"
myArray[129]="blue"
How to quick check that 51 is already set for example?
How to deal with associative arrays?
declare -A myArray
myArray["key1"]="red"
myArray["key2"]="black"
myArray["key3"]="blue"
How to quick check that key2 is already used for example?
To check if the element is set (applies to both indexed and associative array)
[ "${array[key]+abc}" ] && echo "exists"
Basically what ${array[key]+abc} does is
if array[key] is set, return abc
if array[key] is not set, return nothing
References:
See Parameter Expansion in Bash manual and the little note
if the colon is omitted, the operator tests only for existence [of parameter]
This answer is actually adapted from the answers for this SO question: How to tell if a string is not defined in a bash shell script?
A wrapper function:
exists(){
if [ "$2" != in ]; then
echo "Incorrect usage."
echo "Correct usage: exists {key} in {array}"
return
fi
eval '[ ${'$3'[$1]+muahaha} ]'
}
For example
if ! exists key in array; then echo "No such array element"; fi
From man bash, conditional expressions:
-v varname
True if the shell variable varname is set (has been assigned a value).
example:
declare -A foo
foo[bar]="this is bar"
foo[baz]=""
if [[ -v "foo[bar]" ]] ; then
echo "foo[bar] is set"
fi
if [[ -v "foo[baz]" ]] ; then
echo "foo[baz] is set"
fi
if [[ -v "foo[quux]" ]] ; then
echo "foo[quux] is set"
fi
This will show that both foo[bar] and foo[baz] are set (even though the latter is set to an empty value) and foo[quux] is not.
New answer
From version 4.2 of bash (and newer), there is a new -v option to built-in test command.
From version 4.3, this test could address element of arrays.
array=([12]="red" [51]="black" [129]="blue")
for i in 10 12 30 {50..52} {128..131};do
if [ -v 'array[i]' ];then
echo "Variable 'array[$i]' is defined"
else
echo "Variable 'array[$i]' not exist"
fi
done
Variable 'array[10]' not exist
Variable 'array[12]' is defined
Variable 'array[30]' not exist
Variable 'array[50]' not exist
Variable 'array[51]' is defined
Variable 'array[52]' not exist
Variable 'array[128]' not exist
Variable 'array[129]' is defined
Variable 'array[130]' not exist
Variable 'array[131]' not exist
Note: regarding ssc's comment, I've single quoted 'array[i]' in -v test, in order to satisfy shellcheck's error SC2208. This seem not really required here, because there is no glob character in array[i], anyway...
This work with associative arrays in same way:
declare -A aArray=([foo]="bar" [bar]="baz" [baz]=$'Hello world\041')
for i in alpha bar baz dummy foo test;do
if [ -v 'aArray[$i]' ];then
echo "Variable 'aArray[$i]' is defined"
else
echo "Variable 'aArray[$i]' not exist"
fi
done
Variable 'aArray[alpha]' not exist
Variable 'aArray[bar]' is defined
Variable 'aArray[baz]' is defined
Variable 'aArray[dummy]' not exist
Variable 'aArray[foo]' is defined
Variable 'aArray[test]' not exist
With a little difference:In regular arrays, variable between brackets ([i]) is integer, so dollar symbol ($) is not required, but for associative array, as key is a word, $ is required ([$i])!
Old answer for bash prior to V4.2
Unfortunately, bash give no way to make difference betwen empty and undefined variable.
But there is some ways:
$ array=()
$ array[12]="red"
$ array[51]="black"
$ array[129]="blue"
$ echo ${array[#]}
red black blue
$ echo ${!array[#]}
12 51 129
$ echo "${#array[#]}"
3
$ printf "%s\n" ${!array[#]}|grep -q ^51$ && echo 51 exist
51 exist
$ printf "%s\n" ${!array[#]}|grep -q ^52$ && echo 52 exist
(give no answer)
And for associative array, you could use the same:
$ unset array
$ declare -A array
$ array["key1"]="red"
$ array["key2"]="black"
$ array["key3"]="blue"
$ echo ${array[#]}
blue black red
$ echo ${!array[#]}
key3 key2 key1
$ echo ${#array[#]}
3
$ set | grep ^array=
array=([key3]="blue" [key2]="black" [key1]="red" )
$ printf "%s\n" ${!array[#]}|grep -q ^key2$ && echo key2 exist || echo key2 not exist
key2 exist
$ printf "%s\n" ${!array[#]}|grep -q ^key5$ && echo key5 exist || echo key5 not exist
key5 not exist
You could do the job without the need of externals tools (no printf|grep as pure bash), and why not, build checkIfExist() as a new bash function:
$ checkIfExist() {
eval 'local keys=${!'$1'[#]}';
eval "case '$2' in
${keys// /|}) return 0 ;;
* ) return 1 ;;
esac";
}
$ checkIfExist array key2 && echo exist || echo don\'t
exist
$ checkIfExist array key5 && echo exist || echo don\'t
don't
or even create a new getIfExist bash function that return the desired value and exit with false result-code if desired value not exist:
$ getIfExist() {
eval 'local keys=${!'$1'[#]}';
eval "case '$2' in
${keys// /|}) echo \${$1[$2]};return 0 ;;
* ) return 1 ;;
esac";
}
$ getIfExist array key1
red
$ echo $?
0
$ # now with an empty defined value
$ array["key4"]=""
$ getIfExist array key4
$ echo $?
0
$ getIfExist array key5
$ echo $?
1
What about a -n test and the :- operator?
For example, this script:
#!/usr/bin/env bash
set -e
set -u
declare -A sample
sample["ABC"]=2
sample["DEF"]=3
if [[ -n "${sample['ABC']:-}" ]]; then
echo "ABC is set"
fi
if [[ -n "${sample['DEF']:-}" ]]; then
echo "DEF is set"
fi
if [[ -n "${sample['GHI']:-}" ]]; then
echo "GHI is set"
fi
Prints:
ABC is set
DEF is set
tested in bash 4.3.39(1)-release
declare -A fmap
fmap['foo']="boo"
key='foo'
# should echo foo is set to 'boo'
if [[ -z "${fmap[${key}]}" ]]; then echo "$key is unset in fmap"; else echo "${key} is set to '${fmap[${key}]}'"; fi
key='blah'
# should echo blah is unset in fmap
if [[ -z "${fmap[${key}]}" ]]; then echo "$key is unset in fmap"; else echo "${key} is set to '${fmap[${key}]}'"; fi
Reiterating this from Thamme:
[[ ${array[key]+Y} ]] && echo Y || echo N
This tests if the variable/array element exists, including if it is set to a null value. This works with a wider range of bash versions than -v and doesn't appear sensitive to things like set -u. If you see a "bad array subscript" using this method please post an example.
This is the easiest way I found for scripts.
<search> is the string you want to find, ASSOC_ARRAY the name of the variable holding your associative array.
Dependign on what you want to achieve:
key exists:
if grep -qe "<search>" <(echo "${!ASSOC_ARRAY[#]}"); then echo key is present; fi
key exists not:
if ! grep -qe "<search>" <(echo "${!ASSOC_ARRAY[#]}"); then echo key not present; fi
value exists:
if grep -qe "<search>" <(echo "${ASSOC_ARRAY[#]}"); then echo value is present; fi
value exists not:
if ! grep -qe "<search>" <(echo "${ASSOC_ARRAY[#]}"); then echo value not present; fi
I wrote a function to check if a key exists in an array in Bash:
# Check if array key exists
# Usage: array_key_exists $array_name $key
# Returns: 0 = key exists, 1 = key does NOT exist
function array_key_exists() {
local _array_name="$1"
local _key="$2"
local _cmd='echo ${!'$_array_name'[#]}'
local _array_keys=($(eval $_cmd))
local _key_exists=$(echo " ${_array_keys[#]} " | grep " $_key " &>/dev/null; echo $?)
[[ "$_key_exists" = "0" ]] && return 0 || return 1
}
Example
declare -A my_array
my_array['foo']="bar"
if [[ "$(array_key_exists 'my_array' 'foo'; echo $?)" = "0" ]]; then
echo "OK"
else
echo "ERROR"
fi
Tested with GNU bash, version 4.1.5(1)-release (i486-pc-linux-gnu)
For all time people, once and for all.
There's a "clean code" long way, and there is a shorter, more concise, bash centered way.
$1 = The index or key you are looking for.
$2 = The array / map passed in by reference.
function hasKey ()
{
local -r needle="${1:?}"
local -nr haystack=${2:?}
for key in "${!haystack[#]}"; do
if [[ $key == $needle ]] ;
return 0
fi
done
return 1
}
A linear search can be replaced by a binary search, which would perform better with larger data sets. Simply count and sort the keys first, then do a classic binary halving of of the haystack as you get closer and closer to the answer.
Now, for the purist out there that is like "No, I want the more performant version because I may have to deal with large arrays in bash," lets look at a more bash centered solution, but one that maintains clean code and the flexibility to deal with arrays or maps.
function hasKey ()
{
local -r needle="${1:?}"
local -nr haystack=${2:?}
[ -n ${haystack["$needle"]+found} ]
}
The line [ -n ${haystack["$needle"]+found} ]uses the ${parameter+word} form of bash variable expansion, not the ${parameter:+word} form, which attempts to test the value of a key, too, which is not the matter at hand.
Usage
local -A person=(firstname Anthony lastname Rutledge)
if hasMapKey "firstname" person; then
# Do something
fi
When not performing substring expansion, using the form described
below (e.g., ‘:-’), Bash tests for a parameter that is unset or null.
Omitting the colon results in a test only for a parameter that is
unset. Put another way, if the colon is included, the operator tests
for both parameter’s existence and that its value is not null; if the
colon is omitted, the operator tests only for existence.
${parameter:-word}
If parameter is unset or null, the expansion of word is substituted. Otherwise, the value of parameter is substituted.
${parameter:=word}
If parameter is unset or null, the expansion of word is assigned to parameter. The value of parameter is then substituted. Positional
parameters and special parameters may not be assigned to in this way.
${parameter:?word}
If parameter is null or unset, the expansion of word (or a message to that effect if word is not present) is written to the standard
error and the shell, if it is not interactive, exits. Otherwise, the
value of parameter is substituted. ${parameter:+word}
If parameter is null or unset, nothing is substituted, otherwise the expansion of word is substituted.
https://www.gnu.org/savannah-checkouts/gnu/bash/manual/bash.html#Shell-Parameter-Expansion
If $needle does not exist expand to nothing, otherwise expand to the non-zero length string, "found". This will make the -n test succeed if the $needle in fact does exist (as I say "found"), and fail otherwise.
Both in the case of arrays and hash maps I find the easiest and more straightforward solution is to use the matching operator =~.
For arrays:
myArray=("red" "black" "blue")
if [[ " ${myArray[#]} " =~ " blue " ]]; then
echo "blue exists in myArray"
else
echo "blue does not exist in myArray"
fi
NOTE: The spaces around the array guarantee the first and last element can match. The spaces around the value guarantee an exact match.
For hash maps, it's actually the same solution since printing a hash map as a string gives you a list of its values.
declare -A myMap
myMap=(
["key1"]="red"
["key2"]="black"
["key3"]="blue"
)
if [[ " ${myMap[#]} " =~ " blue " ]]; then
echo "blue exists in myMap"
else
echo "blue does not exist in myMap"
fi
But what if you would like to check whether a key exists in a hash map? In the case you can use the ! operator which gives you the list of keys in a hash map.
if [[ " ${!myMap[#]} " =~ " key3 " ]]; then
echo "key3 exists in myMap"
else
echo "key3 does not exist in myMap"
fi
I get bad array subscript error when the key I'm checking is not set. So, I wrote a function that loops over the keys:
#!/usr/bin/env bash
declare -A helpList
function get_help(){
target="$1"
for key in "${!helpList[#]}";do
if [[ "$key" == "$target" ]];then
echo "${helpList["$target"]}"
return;
fi
done
}
targetValue="$(get_help command_name)"
if [[ -z "$targetvalue" ]];then
echo "command_name is not set"
fi
It echos the value when it is found & echos nothing when not found. All the other solutions I tried gave me that error.
Folks,
I have an array, ex,
declare -a arr=("crm" "hr" "pos")
I need to output error if the passed value doesn't exist in this array
I'm trying this use below snippet but it prints "No match found" for any value
match=0
for i in "${arr[#]}"; do
if ! [[ $2 == "$i" ]]; then
match=1
break
fi
done
if [[ $match = 1 ]]; then
echo "No match found"
fi
Any idea how to loop in array and popup error if value doesn't exist ?
There are already answers about your question see check value is in an array, but a fix/idea for your specific approach is something like.
#!/usr/bin/env bash
declare -a arr=("crm" "hr" "pos")
match=0
for i in "${arr[#]}"; do
if ! [[ $2 == "$i" ]]; then
((match++))
fi
done
if (( match == ${#arr[*]} )); then
printf >&2 "No match found\n"
fi
The above script increments match every time the test inside the for loop is true, and in the end compare match with the length of the array ${#arr[*]}. A more verbose output is to put set -x on after the shebang and add a $ sign to the variable match (which is not required) inside the (( )).
if (( $match == ${#arr[*]} )); then
Your original approach always breaks the loop when it does not have a match, doing so will not continue the loop.
You reversed the logic. Just leave out the ! and swap the final test:
match=0
for i in "${arr[#]}"; do
if [[ $2 == "$i" ]]; then
match=1
break
fi
done
if [[ $match = 0 ]]; then
echo "No match found"
fi
This doesn't require a loop.
c.f. if a 2 strings BOTH present in 1 array in a bash script
$: x=bar
$: [[ " ${arr[*]} " =~ " $x " ]] && echo found || echo nope
nope
$: x=hr
$: [[ " ${arr[*]} " =~ " $x " ]] && echo found || echo nope
found
or
$: match=0
$: set -- foo bar
$: [[ " ${arr[*]} " =~ " $2 " ]] && match=1
$: echo match
0
$: set -- foo crm
$: [[ " ${arr[*]} " =~ " $2 " ]] && match=1
$: echo match
1
The logic seems incorrect.
If it does not match, you break the loop.
If it does match, the loop goes to the next iteration. Then it becomes unmatched and finally breaks the loop
declare -a arr=("crm" "hr" "pos")
not_match=0
for i in "${arr[#]}"; do
if [ "$2" = "$i" ]; then
not_match=1
break
fi
done
if [ $not_match -eq 0 ]; then
echo "No match found"
fi
I am trying to compare an array with a value and print an error statement if the match is not found.
arraylist="$(ls new-dir/ | cut -d' ' -f1)"
For example, this stores values such as small, large and medium which are the files present in new-dir.
The value to be compared with will be entered by the user viz. var
I have tried something like following:
(for i in "${arraylist[#]}"; do [[ "$i" == "$var"]] && exit 0; done) && echo "found" || echo "not found"
Also tried, however, doesn't work:
arraylist="$(ls new-dir/ | cut -d' ' -f1)"
count=0
for((i=0; i<${#arraylist[#]}; i++)); do
if [ "$arraylist[$i]" == "$var" ] ; then
count=1
fi
done
if [ $count -eq 0 ]; then
echo "Not found"
fi
Is there any other way to do this comparison?
This code works. Just replace arraylist with your array.
arraylist=('hello' 'world')
var='hello'
count=0
for i in "${arraylist[#]}"
do
if [ "$i" == "$var" ]; then
count=1
fi
done
if [ $count -eq 0 ]; then
echo "Not found"
fi
To extract the first "word" from each filename, I'd do
declare -A prefixes
cd new-dir
for file in *; do
read -r prefix _ <<< "$file"
prefixes["$prefix"]=1
done
cd -
then to look for a match:
# $var is somehow provided
result=""
for p in "${!prefixes[#]}"; do
if [[ $p == "$var" ]]; then
result=found
break
fi
done
echo "${result:-not found}"
This requires bash v4.0+ for the use of an associative array.
If you have bash v4.3+ you can do
[[ -v prefixes[$var] ]] && echo found || echo not found
Alternately:
shopt -s nullglob
files=( new-dir/"$var "* )
(( ${#files[#]} > 0 )) && echo found || echo not found
This is what shell programming is about. Keep it simple :
Array1=( "item1" "item2" "item3" "item-4" )
var="item3"
count=$(echo ${Array1[#]} | tr ' ' '\n' | awk '$1 == "'"$var"'"{print $0}' | wc -l)
[ $count -eq 0 ] && echo "Not found" || echo "found"
The arraylist might be an array with just one index.
The command:
arraylist="$(ls new-dir/ | cut -d' ' -f1)"
might just assign whole "ls new-dir" output to ${arraylist[0]}
You can check the index value in an array by echo ${arraylist[1]} (to confirm).
Try changing the command to generate an array for a list of files/dirs to:
arraylist=($(ls new-dir/))
The complete script:
arraylist=($(ls new-dir/))
(for i in "${arraylist[#]}"; do [[ "$i" == "$var" ]] && exit 0; done) && echo "found" || echo "not found"
You can also ignore the whole array assignment and just use subshell-command in for loop, eg:
(for i in $(ls -1 new-dir/); do [[ "$i" == "$var" ]] && exit 0; done) && echo "found" || echo "not found"
Remember, no quotes " around $(ls -1 new-dir/)
Another one-liner without any array or loops:
ls -1 new-dir/ | grep -q "$var" && echo "found" || echo "not found"
Edit:
As #M. Nejat Aydin suggested, use [[ -e new-dir/$var ]] && echo "found" || echo "Not found" and do not use ls in the script.
I am trying to convert the following script which I use to create archives into one which extracts them.
[[ $# -lt 2 ]] && exit 1
name=$1; shift
files=("$#")
#exclude all files/directories that are not readable
for index in "${!files[#]}"; do
[[ -r ${files[index]} ]] || unset "files[index]"
done
[[ ${#files[#]} -eq 0 ]] && exit 1
if tar -czvf "${name:-def_$$}.tar.gz" "${files[#]}"; then
echo "Ok"
else
echo "Error"
exit 1
fi
So far I have this:
[[ $# -lt 1 ]] && exit 1
files=("$#")
#remove files and directories which are not readable
for index in "${!files[#]}"; do
[[ -r ${files[index]} ]] || unset "files[index]"
done
[[ ${#files[#]} -eq 0 ]] && exit 1
if tar -xzvf "${files[#]}".tar.gz; then
echo "OK"
else
echo "Error"
exit 1
fi
I dont know whether I needed to keep the shift as for this script I do not need to discard any arguments. I want to be able to take them all and unzip each one. Also I see there is a -C switch which allows the user to choose where the unzipped files go. How would I go about also adding this as an option for the user because they may or may not want to change the directory where the files get unzipped to.
You unfortunately can't just do tar -xzvf one.tar.gz two.tar.gz. Straightforward approach is to use a good old for loop:
for file in "${files[#]}"; do
tar -xzvf "$file"
done
Or you can use this:
cat "${files[#]}" | tar -xzvf - -i
You can have the first argument to be the specified directory for the -C option:
[[ $# -lt 2 ]] && exit 1
target=$1; shift
files=("$#")
#remove files and directories which are not readable
for index in "${!files[#]}"; do
[[ -r ${files[index]} ]] || unset "files[index]"
done
[[ ${#files[#]} -eq 0 ]] && exit 1
mkdir -p -- "$target" || exit 1
for file in "${files[#]}"; do
tar -xzvf "$file" -C "$target"
done
./script /some/path one.tar.gz two.tar.gz
List of files for tar can be also constructed like this:
target=$1; shift
for file; do
[[ -r $file ]] && files+=("$file")
done
I'm having problems getting a variable "${Error[*]}", which is a regular indexed array, to stay set from the time it's declared until it's checked. It seems to me that a sub-shell must be launched so the declaration doesn't stick. I didn't think sub-shells were opened when using braces { stuff...; }. I want to know how to get my variable, Error to stick in the case I'm trying to write up. Here's a sample of my script:
TestFunction () {
unset Error
local archive="$1" extlist="$2" && local ext="${archive##*.}"
shopt -s nocasematch
local -i run=0
while [[ "$run" == 0 || -n "${Error[run]}" ]]; do
(( run++ ))
local IFS=$'\n\r\t '
if [[ ! "${Error[*]}" =~ 'cpio' && "$ext" =~ ^(pax|cpio|cpgz|igz|ipa|cab)$ && -n "$(which 'cpio')" ]]; then
## Try to cpio the archive. Since cpio cannot handle '.cab' archive, I want to declare an Error ##
{ cpio -ti --quiet <"$archive" 2>'/dev/null' || local -a Error[run]='cpio'; } | grep -Ei '$extlist'
elif [[ ! "${Error[*]}" =~ 'zipinfo' && "$ext" =~ ^(zip|[jw]ar|ipa|cab)$ && -n "$(which 'unzip')" ]]; then
## If cpio fails, then try zipinfo, or unzip on the next run through the loop... ##
if which 'zipinfo' &>'/dev/null'; then
{ zipinfo -1 "$archive" 2>'/dev/null' || local -a Error[run]='zipinfo'; } | grep -Ei "$scanlist"
elif which 'unzip' &>'/dev/null'; then
{ unzip -lqq "$archive" 2>'/dev/null' || local -a Error[run]='unzip'; } | gsed -re '/^ +[0-9]+/!d;s|^ +[0-9]+ +[0-9-]+ [0-9:]+ +||' | grep -Ei "$exlist"
fi
## many more elifs... ##
fi
done
shopt -u nocasematch
return 0
}
Archives='\.(gnutar|7-zip|lharc|toast|7zip|boz|bzi?p2?|cpgz|cpio|gtar|g?z(ip)?|lzma(86)?|t[bg]z2?|ar[cgjk]|bz[2a]?|cb[7rz]|cdr|deb|[dt]lz|dmg|exe|fbz|fgz|gz[aip]|igz|img|iso|lh[az]|lz[hmswx]?|mgz|mpv|mpz|pax|piz|pka|[jrtwx]ar|rpm|s?7-?z|sitx?|m?pkg|sfx|nz|xz)$'
IFS=$'\n'
declare -a List=($(TestFunction '/Users/aesthir/Programming/│My Projects│/Swipe Master/Test Folder/SDKSetup.cab' "$Archives"))
IFS=$' \t\n'
xtrace output:
〔xtrace〕 unset Error
〔xtrace〕 local 'archive=/Users/aesthir/Programming/│My Projects│/Swipe Master/Test Folder/SDKSetup.cab' 'extlist=\.(gnutar|7-zip|lharc|toast|7zip|boz|bzi?p2?|cpgz|cpio|gtar|g?z(ip)?|lzma(86)?|t[bg]z2?|ar[cgjk]|bz[2a]?|cb[7rz]|cdr|deb|[dt]lz|dmg|exe|fbz|fgz|gz[aip]|igz|img|iso|lh[az]|lz[hmswx]?|mgz|mpv|mpz|pax|piz|pka|[jrtwx]ar|rpm|s?7-?z|sitx?|m?pkg|sfx|nz|xz)$'
〔xtrace〕 local ext=cab
〔xtrace〕 shopt -s nocasematch
〔xtrace〕 local -i run=0
〔xtrace〕 [[ 0 == 0 ]]
〔xtrace〕 (( run++ ))
〔xtrace〕 local 'IFS=
'
〔xtrace〕 [[ ! '' =~ cpio ]]
〔xtrace〕 [[ cab =~ ^(pax|cpio|cpgz|igz|ipa|cab)$ ]]
〔xtrace〕 which cpio
〔xtrace〕 [[ -n /usr/bin/cpio ]]
〔xtrace〕 grep -Ei '$extlist'
〔xtrace〕 cpio -ti --quiet
〔xtrace〕 local -a 'Error[run]=cpio'
〔xtrace〕 [[ 1 == 0 ]]
〔xtrace〕 [[ -n '' ]] ## <—— Problem is here... when checking "${Error[run]}", it's unset ##
〔xtrace〕 shopt -u nocasematch
〔xtrace〕 return 0
Now obviously I know cpio, zipinfo, and unzip cannot handle cab files... I put 'cab' in the extension list on purpose to cause an error.
I want to stay in TestFunction and keep looping with different archivers until a success (file list is dumped, which cabextract would gladly do in this case) without repeating an already failed archiver.
Finally, since this works fine...
TestFunction () {
unset Error
local archive="$1" extlist="$2" && local ext="${archive##*.}"
local -i run=0
while [[ "$run" == 0 || -n "${Error[run]}" ]]; do
(( run++ ))
local IFS=$'\n\r\t '
if [[ ! "${Error[*]}" =~ 'cpio' && "$ext" =~ ^(pax|cpio|cpgz|igz|ipa|cab)$ && -n "$(which 'cpio')" ]]; then
cpio -ti --quiet <"$archive" 2>'/dev/null' || local -a Error[run]='cpio'
fi
done
shopt -u nocasematch
return 0
}
... I have to assume the problem is the braces because I want the results grep'd right away. However, I need those braces there because I don't want Error[run] to be set if grep turns up no results, only if cpio fails. I dont want to grep outside TestFunction for other reasons (I would have to do a complete re-write).
Any quick solution to this without massive rewriting? Maybe echo 'cpio' to some fd and read -u6ing it somehow?
I'd much prefer not to have to set an array to the file list and then for loop | grep through every file as it would really slow things down.
The problem is not the braces, but the pipe. Because you're using a pipe, the assignment to Error[run] is happening in a subshell, so that assignment disappears when the subshell exits.
Change:
{ cpio -ti --quiet <"$archive" 2>'/dev/null' || local -a Error[run]='cpio'; } | grep -Ei '$extlist'
to:
cpio -ti --quiet <"$archive" 2>'/dev/null' | grep -Ei "$extlist"
[[ ${PIPESTATUS[0]} -ne 0 ]] && Error[run]='cpio'
(btw, need double quotes in the grep part)