I am trying to replace all the word "null" to elements in array. The problem is that after replacing one word of "null", I would like to replace the next "null" with next element in the array.
I am not very good with bash and I feel like this is quite a basic question.
Here is what I have so far:
for m in $(cat finalfile.csv)
do
if [ "$m" = "null" ]
then
m=cwearray[$counter]
let counter++
fi
done
This doesn't replace anything in the finalfile.csv.
For example if the file has:
"value1","value2","null","value3"\n
"value1","value2","null","value3"...
and the array has ["foo","bar"]
I would like it to be:
"value1","value2","foo","value3"\n
"value1","value2","bar","value3"...
can be done with bash, even with multiple nulls per line:
$ cat finalfile.csv
"value1","value2","null","null"
"value1","value2","null","value3"
$ cwearray=( foo bar baz )
$ idx=0
$ while read -r line; do
while [[ $line == *null* ]]; do
line=${line/null/${cwearray[idx++]}}
# ...............^^^^^^^^^^^^^^^^^^
# replace the _first_ "null" with the _next_ array element
done
echo "$line"
done < finalfile.csv > updatedfinalfile.csv
$ cat updatedfinalfile.csv
"value1","value2","foo","bar"
"value1","value2","baz","value3"
It's easier in Perl where you can increase the index directly in the replacement part of a substitution:
printf '%s\n' 1,2,3,null null,2,3,4 null,null,null,null \
| perl -pe 'BEGIN { #cwe = qw( A B C D E F ) }
s/(?:^|(?<=,))null(?=,|$)/$cwe[$i++]/g'
Update: It seems you've updated your question with a sample input. If nulls are double quoted, it gets even easier, as there's no need to check whether they're surrounded with commas or beginning/end of the line.
perl -pe 'BEGIN{ #cwe = qw( foo bar ) }
s/"null"/"$cwe[$i++]"/g'
An awk solution :
declare -a cwearray
cwearray=(foo bar)
awk -F, 'NR==FNR{repl[NR]=$0; next}{for(i=1;i<=NF;i++){if($i=="\"null\""){$i="\""repl[++counter]"\""}}}1' OFS="," <(for i in "${cwearray[#]}"; do echo "$i"; done) <file>
Read the file line by line. If a line contains null, then use sed to replace all occurrences of null with the corresponding value, retrieved via array index.
#!/bin/bash
file="finalfile.csv"
counter=0
array=(
"foo"
"bar"
)
while read -r line; do
item="${array[$counter]}"
echo "$line" | sed "s/null/$item/g"
((counter++))
done < "$file"
I need to remove an element from an array in bash shell.
Generally I'd simply do:
array=("${(#)array:#<element to remove>}")
Unfortunately the element I want to remove is a variable so I can't use the previous command.
Down here an example:
array+=(pluto)
array+=(pippo)
delete=(pluto)
array( ${array[#]/$delete} ) -> but clearly doesn't work because of {}
Any idea?
The following works as you would like in bash and zsh:
$ array=(pluto pippo)
$ delete=pluto
$ echo ${array[#]/$delete}
pippo
$ array=( "${array[#]/$delete}" ) #Quotes when working with strings
If need to delete more than one element:
...
$ delete=(pluto pippo)
for del in ${delete[#]}
do
array=("${array[#]/$del}") #Quotes when working with strings
done
Caveat
This technique actually removes prefixes matching $delete from the elements, not necessarily whole elements.
Update
To really remove an exact item, you need to walk through the array, comparing the target to each element, and using unset to delete an exact match.
array=(pluto pippo bob)
delete=(pippo)
for target in "${delete[#]}"; do
for i in "${!array[#]}"; do
if [[ ${array[i]} = $target ]]; then
unset 'array[i]'
fi
done
done
Note that if you do this, and one or more elements is removed, the indices will no longer be a continuous sequence of integers.
$ declare -p array
declare -a array=([0]="pluto" [2]="bob")
The simple fact is, arrays were not designed for use as mutable data structures. They are primarily used for storing lists of items in a single variable without needing to waste a character as a delimiter (e.g., to store a list of strings which can contain whitespace).
If gaps are a problem, then you need to rebuild the array to fill the gaps:
for i in "${!array[#]}"; do
new_array+=( "${array[i]}" )
done
array=("${new_array[#]}")
unset new_array
You could build up a new array without the undesired element, then assign it back to the old array. This works in bash:
array=(pluto pippo)
new_array=()
for value in "${array[#]}"
do
[[ $value != pluto ]] && new_array+=($value)
done
array=("${new_array[#]}")
unset new_array
This yields:
echo "${array[#]}"
pippo
This is the most direct way to unset a value if you know it's position.
$ array=(one two three)
$ echo ${#array[#]}
3
$ unset 'array[1]'
$ echo ${array[#]}
one three
$ echo ${#array[#]}
2
This answer is specific to the case of deleting multiple values from large arrays, where performance is important.
The most voted solutions are (1) pattern substitution on an array, or (2) iterating over the array elements. The first is fast, but can only deal with elements that have distinct prefix, the second has O(n*k), n=array size, k=elements to remove. Associative array are relative new feature, and might not have been common when the question was originally posted.
For the exact match case, with large n and k, possible to improve performance from O(nk) to O(n+klog(k)). In practice, O(n) assuming k much lower than n. Most of the speed up is based on using associative array to identify items to be removed.
Performance (n-array size, k-values to delete). Performance measure seconds of user time
N K New(seconds) Current(seconds) Speedup
1000 10 0.005 0.033 6X
10000 10 0.070 0.348 5X
10000 20 0.070 0.656 9X
10000 1 0.043 0.050 -7%
As expected, the current solution is linear to N*K, and the fast solution is practically linear to K, with much lower constant. The fast solution is slightly slower vs the current solution when k=1, due to additional setup.
The 'Fast' solution: array=list of input, delete=list of values to remove.
declare -A delk
for del in "${delete[#]}" ; do delk[$del]=1 ; done
# Tag items to remove, based on
for k in "${!array[#]}" ; do
[ "${delk[${array[$k]}]-}" ] && unset 'array[k]'
done
# Compaction
array=("${array[#]}")
Benchmarked against current solution, from the most-voted answer.
for target in "${delete[#]}"; do
for i in "${!array[#]}"; do
if [[ ${array[i]} = $target ]]; then
unset 'array[i]'
fi
done
done
array=("${array[#]}")
Here's a one-line solution with mapfile:
$ mapfile -d $'\0' -t arr < <(printf '%s\0' "${arr[#]}" | grep -Pzv "<regexp>")
Example:
$ arr=("Adam" "Bob" "Claire"$'\n'"Smith" "David" "Eve" "Fred")
$ echo "Size: ${#arr[*]} Contents: ${arr[*]}"
Size: 6 Contents: Adam Bob Claire
Smith David Eve Fred
$ mapfile -d $'\0' -t arr < <(printf '%s\0' "${arr[#]}" | grep -Pzv "^Claire\nSmith$")
$ echo "Size: ${#arr[*]} Contents: ${arr[*]}"
Size: 5 Contents: Adam Bob David Eve Fred
This method allows for great flexibility by modifying/exchanging the grep command and doesn't leave any empty strings in the array.
Partial answer only
To delete the first item in the array
unset 'array[0]'
To delete the last item in the array
unset 'array[-1]'
To expand on the above answers, the following can be used to remove multiple elements from an array, without partial matching:
ARRAY=(one two onetwo three four threefour "one six")
TO_REMOVE=(one four)
TEMP_ARRAY=()
for pkg in "${ARRAY[#]}"; do
for remove in "${TO_REMOVE[#]}"; do
KEEP=true
if [[ ${pkg} == ${remove} ]]; then
KEEP=false
break
fi
done
if ${KEEP}; then
TEMP_ARRAY+=(${pkg})
fi
done
ARRAY=("${TEMP_ARRAY[#]}")
unset TEMP_ARRAY
This will result in an array containing:
(two onetwo three threefour "one six")
Here's a (probably very bash-specific) little function involving bash variable indirection and unset; it's a general solution that does not involve text substitution or discarding empty elements and has no problems with quoting/whitespace etc.
delete_ary_elmt() {
local word=$1 # the element to search for & delete
local aryref="$2[#]" # a necessary step since '${!$2[#]}' is a syntax error
local arycopy=("${!aryref}") # create a copy of the input array
local status=1
for (( i = ${#arycopy[#]} - 1; i >= 0; i-- )); do # iterate over indices backwards
elmt=${arycopy[$i]}
[[ $elmt == $word ]] && unset "$2[$i]" && status=0 # unset matching elmts in orig. ary
done
return $status # return 0 if something was deleted; 1 if not
}
array=(a 0 0 b 0 0 0 c 0 d e 0 0 0)
delete_ary_elmt 0 array
for e in "${array[#]}"; do
echo "$e"
done
# prints "a" "b" "c" "d" in lines
Use it like delete_ary_elmt ELEMENT ARRAYNAME without any $ sigil. Switch the == $word for == $word* for prefix matches; use ${elmt,,} == ${word,,} for case-insensitive matches; etc., whatever bash [[ supports.
It works by determining the indices of the input array and iterating over them backwards (so deleting elements doesn't screw up iteration order). To get the indices you need to access the input array by name, which can be done via bash variable indirection x=1; varname=x; echo ${!varname} # prints "1".
You can't access arrays by name like aryname=a; echo "${$aryname[#]}, this gives you an error. You can't do aryname=a; echo "${!aryname[#]}", this gives you the indices of the variable aryname (although it is not an array). What DOES work is aryref="a[#]"; echo "${!aryref}", which will print the elements of the array a, preserving shell-word quoting and whitespace exactly like echo "${a[#]}". But this only works for printing the elements of an array, not for printing its length or indices (aryref="!a[#]" or aryref="#a[#]" or "${!!aryref}" or "${#!aryref}", they all fail).
So I copy the original array by its name via bash indirection and get the indices from the copy. To iterate over the indices in reverse I use a C-style for loop. I could also do it by accessing the indices via ${!arycopy[#]} and reversing them with tac, which is a cat that turns around the input line order.
A function solution without variable indirection would probably have to involve eval, which may or may not be safe to use in that situation (I can't tell).
Using unset
To remove an element at particular index, we can use unset and then do copy to another array. Only just unset is not required in this case. Because unset does not remove the element it just sets null string to the particular index in array.
declare -a arr=('aa' 'bb' 'cc' 'dd' 'ee')
unset 'arr[1]'
declare -a arr2=()
i=0
for element in "${arr[#]}"
do
arr2[$i]=$element
((++i))
done
echo "${arr[#]}"
echo "1st val is ${arr[1]}, 2nd val is ${arr[2]}"
echo "${arr2[#]}"
echo "1st val is ${arr2[1]}, 2nd val is ${arr2[2]}"
Output is
aa cc dd ee
1st val is , 2nd val is cc
aa cc dd ee
1st val is cc, 2nd val is dd
Using :<idx>
We can remove some set of elements using :<idx> also. For example if we want to remove 1st element we can use :1 as mentioned below.
declare -a arr=('aa' 'bb' 'cc' 'dd' 'ee')
arr2=("${arr[#]:1}")
echo "${arr2[#]}"
echo "1st val is ${arr2[1]}, 2nd val is ${arr2[2]}"
Output is
bb cc dd ee
1st val is cc, 2nd val is dd
http://wiki.bash-hackers.org/syntax/pe#substring_removal
${PARAMETER#PATTERN} # remove from beginning
${PARAMETER##PATTERN} # remove from the beginning, greedy match
${PARAMETER%PATTERN} # remove from the end
${PARAMETER%%PATTERN} # remove from the end, greedy match
In order to do a full remove element, you have to do an unset command with an if statement. If you don't care about removing prefixes from other variables or about supporting whitespace in the array, then you can just drop the quotes and forget about for loops.
See example below for a few different ways to clean up an array.
options=("foo" "bar" "foo" "foobar" "foo bar" "bars" "bar")
# remove bar from the start of each element
options=("${options[#]/#"bar"}")
# options=("foo" "" "foo" "foobar" "foo bar" "s" "")
# remove the complete string "foo" in a for loop
count=${#options[#]}
for ((i = 0; i < count; i++)); do
if [ "${options[i]}" = "foo" ] ; then
unset 'options[i]'
fi
done
# options=( "" "foobar" "foo bar" "s" "")
# remove empty options
# note the count variable can't be recalculated easily on a sparse array
for ((i = 0; i < count; i++)); do
# echo "Element $i: '${options[i]}'"
if [ -z "${options[i]}" ] ; then
unset 'options[i]'
fi
done
# options=("foobar" "foo bar" "s")
# list them with select
echo "Choose an option:"
PS3='Option? '
select i in "${options[#]}" Quit
do
case $i in
Quit) break ;;
*) echo "You selected \"$i\"" ;;
esac
done
Output
Choose an option:
1) foobar
2) foo bar
3) s
4) Quit
Option?
Hope that helps.
There is also this syntax, e.g. if you want to delete the 2nd element :
array=("${array[#]:0:1}" "${array[#]:2}")
which is in fact the concatenation of 2 tabs. The first from the index 0 to the index 1 (exclusive) and the 2nd from the index 2 to the end.
POSIX shell script does not have arrays.
So most probably you are using a specific dialect such as bash, korn shells or zsh.
Therefore, your question as of now cannot be answered.
Maybe this works for you:
unset array[$delete]
What I do is:
array="$(echo $array | tr ' ' '\n' | sed "/itemtodelete/d")"
BAM, that item is removed.
This is a quick-and-dirty solution that will work in simple cases but will break if (a) there are regex special characters in $delete, or (b) there are any spaces at all in any items. Starting with:
array+=(pluto)
array+=(pippo)
delete=(pluto)
Delete all entries exactly matching $delete:
array=(`echo $array | fmt -1 | grep -v "^${delete}$" | fmt -999999`)
resulting in
echo $array -> pippo, and making sure it's an array:
echo $array[1] -> pippo
fmt is a little obscure: fmt -1 wraps at the first column (to put each item on its own line. That's where the problem arises with items in spaces.) fmt -999999 unwraps it back to one line, putting back the spaces between items. There are other ways to do that, such as xargs.
Addendum: If you want to delete just the first match, use sed, as described here:
array=(`echo $array | fmt -1 | sed "0,/^${delete}$/{//d;}" | fmt -999999`)
Actually, I just noticed that the shell syntax somewhat has a behavior built-in that allows for easy reconstruction of the array when, as posed in the question, an item should be removed.
# let's set up an array of items to consume:
x=()
for (( i=0; i<10; i++ )); do
x+=("$i")
done
# here, we consume that array:
while (( ${#x[#]} )); do
i=$(( $RANDOM % ${#x[#]} ))
echo "${x[i]} / ${x[#]}"
x=("${x[#]:0:i}" "${x[#]:i+1}")
done
Notice how we constructed the array using bash's x+=() syntax?
You could actually add more than one item with that, the content of a whole other array at once.
In ZSH this is dead easy (note this uses more bash compatible syntax than necessary where possible for ease of understanding):
# I always include an edge case to make sure each element
# is not being word split.
start=(one two three 'four 4' five)
work=(${(#)start})
idx=2
val=${work[idx]}
# How to remove a single element easily.
# Also works for associative arrays (at least in zsh)
work[$idx]=()
echo "Array size went down by one: "
[[ $#work -eq $(($#start - 1)) ]] && echo "OK"
echo "Array item "$val" is now gone: "
[[ -z ${work[(r)$val]} ]] && echo OK
echo "Array contents are as expected: "
wanted=("${start[#]:0:1}" "${start[#]:2}")
[[ "${(j.:.)wanted[#]}" == "${(j.:.)work[#]}" ]] && echo "OK"
echo "-- array contents: start --"
print -l -r -- "-- $#start elements" ${(#)start}
echo "-- array contents: work --"
print -l -r -- "-- $#work elements" "${work[#]}"
Results:
Array size went down by one:
OK
Array item two is now gone:
OK
Array contents are as expected:
OK
-- array contents: start --
-- 5 elements
one
two
three
four 4
five
-- array contents: work --
-- 4 elements
one
three
four 4
five
To avoid conflicts with array index using unset - see https://stackoverflow.com/a/49626928/3223785 and https://stackoverflow.com/a/47798640/3223785 for more information - reassign the array to itself: ARRAY_VAR=(${ARRAY_VAR[#]}).
#!/bin/bash
ARRAY_VAR=(0 1 2 3 4 5 6 7 8 9)
unset ARRAY_VAR[5]
unset ARRAY_VAR[4]
ARRAY_VAR=(${ARRAY_VAR[#]})
echo ${ARRAY_VAR[#]}
A_LENGTH=${#ARRAY_VAR[*]}
for (( i=0; i<=$(( $A_LENGTH -1 )); i++ )) ; do
echo ""
echo "INDEX - $i"
echo "VALUE - ${ARRAY_VAR[$i]}"
done
exit 0
[Ref.: https://tecadmin.net/working-with-array-bash-script/ ]
How about something like:
array=(one two three)
array_t=" ${array[#]} "
delete=one
array=(${array_t// $delete / })
unset array_t
#/bin/bash
echo "# define array with six elements"
arr=(zero one two three 'four 4' five)
echo "# unset by index: 0"
unset -v 'arr[0]'
for i in ${!arr[*]}; do echo "arr[$i]=${arr[$i]}"; done
arr_delete_by_content() { # value to delete
for i in ${!arr[*]}; do
[ "${arr[$i]}" = "$1" ] && unset -v 'arr[$i]'
done
}
echo "# unset in global variable where value: three"
arr_delete_by_content three
for i in ${!arr[*]}; do echo "arr[$i]=${arr[$i]}"; done
echo "# rearrange indices"
arr=( "${arr[#]}" )
for i in ${!arr[*]}; do echo "arr[$i]=${arr[$i]}"; done
delete_value() { # value arrayelements..., returns array decl.
local e val=$1; new=(); shift
for e in "${#}"; do [ "$val" != "$e" ] && new+=("$e"); done
declare -p new|sed 's,^[^=]*=,,'
}
echo "# new array without value: two"
declare -a arr="$(delete_value two "${arr[#]}")"
for i in ${!arr[*]}; do echo "arr[$i]=${arr[$i]}"; done
delete_values() { # arraydecl values..., returns array decl. (keeps indices)
declare -a arr="$1"; local i v; shift
for v in "${#}"; do
for i in ${!arr[*]}; do
[ "$v" = "${arr[$i]}" ] && unset -v 'arr[$i]'
done
done
declare -p arr|sed 's,^[^=]*=,,'
}
echo "# new array without values: one five (keep indices)"
declare -a arr="$(delete_values "$(declare -p arr|sed 's,^[^=]*=,,')" one five)"
for i in ${!arr[*]}; do echo "arr[$i]=${arr[$i]}"; done
# new array without multiple values and rearranged indices is left to the reader
I have a grep output and I'm trying to make an associative array from the output that I get.
Here is my grep output:
"HardwareSerialNumber": "123456789101",
"DeviceId": "devid1234",
"HardwareSerialNumber": "111213141516",
"DeviceId": "devid5678",
I want to use that output to define an associative array, like this:
array[123456789101]=devid1234
array[11213141516]=devid5678
Is that possible? I'm new at making arrays. I hope someone could help me in my problem.
Either pipe your grep output to a helper script with a while loop containing a simple "0/1" toggle to read two lines taking the last field of each to fill your array, e.g.
#!/bin/bash
declare -A array
declare -i n=0
arridx=
while read -r label value; do # read 2 fields
if [ "$n" -eq 0 ]
then
arridx="${value:1}" # strip 1st and lst 2 chars
arridx="${arridx:0:(-2)}" # save in arridx (array index)
((n++)) # increment toggle
else
arrval="${value:1}" # strip 1st and lst 2 chars
arrval="${arrval:0:(-2)}" # save in arrval (array value)
array[$arridx]="$arrval" # assign to associative array
n=0 # zero toggle
fi
done
for i in ${!array[#]}; do # output array
echo "array[$i] ${array[$i]}"
done
Or you can use process substitution containing the grep command within the script to do the same thing, e.g.
done < <( your grep command )
You can also add a check under the else clause that if [[ $label =~ DeviceId ]] to validate you are on the right line and catch any variation in the grep output content.
Example Input
$ cat dat/grepout.txt
"HardwareSerialNumber": "123456789101",
"DeviceId": "devid1234",
"HardwareSerialNumber": "111213141516",
"DeviceId": "devid5678",
Example Use/Output
$ cat dat/grepout.txt | bash parsegrep2array.sh
array[123456789101] devid1234
array[111213141516] devid5678
Parsing out the values is easy, and once you have them you can certainly use those values to build up an array. The trickiest part comes from the fact that you need to combine input from separate lines. Here is one approach; note that this script is verbose on purpose, to show what's going on; once you see what's happening, you can eliminate most of the output:
so.input
"HardwareSerialNumber": "123456789101",
"DeviceId": "devid1234",
"HardwareSerialNumber": "111213141516",
"DeviceId": "devid5678",
so.sh
#!/bin/bash
declare -a hardwareInfo
while [[ 1 ]]; do
# read in two lines of input
# if either line is the last one, we don't have enough input to proceed
read lineA < "${1:-/dev/stdin}"
# if EOF or empty line, exit
if [[ "$lineA" == "" ]]; then break; fi
read lineB < "${1:-/dev/stdin}"
# if EOF or empty line, exit
if [[ "$lineB" == "" ]]; then break; fi
echo "$lineA"
echo "$lineB"
hwsn=$lineA
hwsn=${hwsn//HardwareSerialNumber/}
hwsn=${hwsn//\"/}
hwsn=${hwsn//:/}
hwsn=${hwsn//,/}
echo $hwsn
# some checking could be done here to test that the value is numeric
devid=$lineB
devid=${devid//DeviceId/}
devid=${devid//\"/}
devid=${devid//:/}
devid=${devid//,/}
echo $devid
# some checking could be done here to make sure the value is valid
# populate the array
hardwareInfo[$hwsn]=$devid
done
# spacer, for readability of the output
echo
# display the array; in your script, you would do something different and useful
for key in "${!hardwareInfo[#]}"; do echo $key --- ${hardwareInfo[$key]}; done
cat so.input | ./so.sh
"HardwareSerialNumber": "123456789101",
"DeviceId": "devid1234",
123456789101
devid1234
"HardwareSerialNumber": "111213141516",
"DeviceId": "devid5678",
111213141516
devid5678
111213141516 --- devid5678
123456789101 --- devid1234
I created the input file so.input just for convenience. You would probably pipe your grep output into the bash script, like so:
grep-command | ./so.sh
EDIT #1: There are lots of choices for parsing out the key and value from the strings fed in by grep; the answer from #David C. Rankin shows another way. The best way depends on what you can rely on about the content and structure of the grep output.
There are also several choices for reading two separate lines that are related to each other; David's "toggle" approach is also good, and commonly used; I considered it myself, before going with "read two lines and stop if either is blank".
EDIT #2: I see declare -A in David's answer and in examples on the web; I used declare -a because that's what my version of bash wants (I'm using a Mac). So, just be aware that there can be differences.
I have a text file that has 8000 lines, here is an example
00122;IL;Chicago;Router;;1496009459
00133;IL;Chicago;Router;0;6.651;1496009460
00166;IL;Chicago;Router;0;5.798;1496009460
00177;IL;Chicago;Router;0;5.365;1496009460
00188;IL;Chicago;Router;0;22.347;1496009460
As you can see the file has different count of delimiter, I need to insert all columns separated by ';' to an array no matter when the the delimiter occurs
So the first line would have 6 fields and the second line would have 7.
When I tried do it through the below command
Number=( $(awk '{print $1}' $FileName.txt) ) with different array name and field for each columns, I am getting strange behavior which not all fields are printed for some lines when I echo them all in one line
Performance is very important (need to do it in a matter of seconds )and I found using awk is the fastest approach so far, unless someone has better approach.
An ideas why this is happening ?
To dump the entire text file into an array, I would use the following. In this example, we use the two arrays ${finalarray[]} and ${subarray[]} (though the latter is unset at the end) and the variable $line. We assume the file name is file.txt.
#!/bin/bash
finalarray=()
while read line; do #For each cycle, the variable $line is the next line of the file
if [[ -z $line ]]; then continue; done #If the line is empty, skip this cycle
IFS=";" read -r -a subarray <<< "$line" #Split $line into ${subarray[]} using : as delim
finalarray+=( "$subarray[#]}" ) #Add every element from ${subarray[]} to ${finalarray[]}
unset subarray #clears the array
done <file.txt
If your empty lines are, in fact, populated by spaces or other whitespace characters, the empty line catch won't work. Instead, you could use something like the following to skip any lines not containing semicolons.
if [[ $(echo "$line" | grep -c ";") -eq 0 ]]; then continue; fi
On the other hand, this would skip all lines without a semicolon, even if you intended some of those lines to be a single array entry.
Is it possible to grep an array in bash? Basically I have two arrays, one array I want to loop through and the other array I want to check to see if each string is in the other array or not.
Rough example:
for CLIENTS in ${LIST[#]}; do
#lost as to best way to grep a array with out putting the values in a file.
grep ${server_client_list[#]}
done
You can use grep -f using process substitution:
grep -Ff <(printf "%s\n" "${LIST[#]}") <(printf "%s\n" "${server_client_list[#]}")
Bash provides substring matching. This eliminates the need to spawn external processes and subshells. Simply use:
for CLIENTS in ${LIST[#]}; do
if [[ "${server_client_list[#]}" =~ "$CLIENTS" ]]; then
echo "CLIENTS ($CLIENTS) is in server_client_list"
fi
done
Note: this works for bash, not sh.
You could use the following function :
function IsInList {
local i
for i in "${#:2}"; do
[ "$i" = "$1" ] && return 0
done
return 1
}
for CLIENT in "${LIST[#]}"; do
IsInList "$CLIENT" "${server_client_list[#]}" && echo "It's in the list!"
done
Note that the quotes around ${LIST[#]} and ${server_client_list[#]} are very important because they guarantee the array expansion to expand the way you want them to, instead of having a bad surprise when a space make its way into one of those array values.
Credits : I took this function from patrik's answer in this post when I needed something like that.
Edit :
If you were looking for something with regexp capabilities, you could also use the following :
function IsInList {
local i
for i in "${#:2}"; do
expr match "$i" "$1" && return 0
done
return 1
}