When I run the following code

declare -A X # get an associative array
index="a'b" # a somewhat weird index
X[$index]="this is set"
echo ">"
if test -v X[$index]; then # behaves in an unexpected way
  echo indeed, this is set
else
  echo no, it is not
fi

the result is no, it is not in my bash version 5.1.16(1). As soon as i remove the single quote from the index, it works as expected, telling that indeed, this is set. From the bash manual : > Indexed arrays are referenced using integers [...]; associative arrays use arbitrary strings. Given that I can properly use the index to set and retrieve the value, I wonder if this is a bug in test -v or if there is some explanation why this does not work or whether different quoting can get test -v to work. (I could use test -z in this particular case, but the question is about -v).

I have a lot of associative arrays and i want to use only 1 loop. select the array for loop by a given name I want to select/build a part of the arrayname with a variable and than loop with that name, but it doesn't work. Like in OUTPUT3 and OUTPUT4, but the syntax is wrong. For output 3 i receive: bash wrong substitution For output 4 i receive: only the arrayname and 0

#!/bin/bash
clear

declare -A a1 a2 a3

a1['1']="1-1V"

a2['1']="2-1V"
a2['2']="2-2V"

a3['1']="3-1V"
a3['2']="3-2V"
a3['3']="3-3V"

# 1 OUTPUT WORKS
for i in ${!a1[*]}
do
echo -e "$i : ${a1[$i]}"
done

# 2 OUTPUT WORKS
for i in ${!a2[*]}
do
echo -e "$i : ${a2[$i]}"
done

# 3 OUTPUT - WRONG SYNTAX
selectkey="3"
for i in ${!a$selectkey[@]}
do
echo -e "$i : ${a$selectkey[$i]}"
done

# 4 OUTPUT - WRONG SYNTAX
key="3"
aselect="a${key}[*]"
# THIS ECHO WORKS
echo -e "ARRAY: ${!aselect}"

for i in ${!aselect[@]}
do
echo -e "$i : ${aselect[$i]}"
done

Is there a way to print an entire array ([key]=value) without looping over all elements? Assume I have created an array with some elements: declare -A array array=([a1]=1 [a2]=2 ... [b1]=bbb ... [f500]=abcdef) I can print back the entire array with for i in "${!array[@]}" do echo "${i}=${array[$i]}" done However, it seems bash already knows how to get all array elements in one "go" - both keys ${!array[@]} and values ${array[@]}. Is there a way to make bash print this info without the loop? Edit: typeset -p array does that! However I can't remove both prefix and suffix in a single substitution: a="$(typeset -p array)" b="${a##*(}" c="${b%% )*}" Is there a cleaner way to get/print only the key=value portion of the output?

I have a pipeline that deploys scripts into a temporary dir. I need to rellocate them into their actual proper directory.

#!/usr/bin/sh

DEPLOY_HOME=/opt/xxx

function getDeployedFiles {
    ls ${DEPLOY_HOME} | grep -v pipeline.properties | grep -v Deploy.tmp > 
    ${DEPLOY_HOME}/Deploy.tmp
    chmod 700 ${DEPLOY_HOME}/Deploy.tmp
    readarray -t depFilesArr < ${DEPLOY_HOME}/Deploy.tmp
}

function setDict {
    declare -A dict
    dict=(
        ["a.script.100"]="/opt/xxx/firstpath/100"
        ["b.script.200"]="/opt/xxx/secondpath/200"
        ["c.script.300"]="/opt/xxx/thirdpath/300"
    )
}

function itArr {
    for i in "${depFilesArr[@]}"; do
        FILENAME="${i}"
        if [[ -v "${dict['${i}']}" ]]; then
            echo "Value is present"
            FILEDEST="${dict['${i}']}"
            mv ${DEPLOY_HOME}/${FILENAME} ${FILEDEST}/${FILENAME}
        else
            echo "Value not found, file will remain in ${DEPLOY_HOME}"
        fi
    done
}

#MAIN PROGRAM
getDeployedFiles
setDict 
itArr

The current error I am getting is: "script.sh: line x 'a.script.100': syntax error: operand expected (error token is "'a.script.100'") It doesn't seem to evaluate the "if" properly as it's not printing any of the subsequent echos. Idk wether I'm incorrectly managing the strings or something about my logic is wrong, any help appreciated. BTW I'm using bash 4.4.

I know about https://unix.stackexchange.com/questions/625501/how-to-create-json-from-associative-array but that's not my problem. I have this associative array:

declare -A aliases
aliases[Index]=components/Index/Exports
aliases[Shared]=components/Shared/Exports
aliases[Icons]=components/Icons/Exports

Now I need to convert this associative array into this JSON:

{
    "compilerOptions": {
        "baseUrl": ".",
        "paths": {
            "Index": ["components/Index/Exports"],
            "Shared": ["components/Shared/Exports"],
            "Icons": ["components/Icons/Exports"],
        }
    }
}

I want to use jo and jq. But I can't come up with the nesting. I tried this code:

jo -p compilerOptions[baseUrl]=. compilerOptions[paths]="$(jo -p a ${Aliases[@]})"

But it does not even run.

Let's say I have an associative array in bash, declare -A hash hash=( ["foo"]=aa ["bar"]=bb ["baz"]=aa ["quux"]=bb ["wibble"]=cc ["wobble"]=aa ) where both keys and values are unknown to me (the actual data is read from external sources). How may I create an array of the keys corresponding to the same value, so that I may, in a loop over all unique values, do printf 'Value "%s" is present with the following keys: %s\n' "$value" "${keys[*]}" and get the output (not necessarily in this order) Value "aa" is present with the following keys: foo baz wobble Value "bb" is present with the following keys: bar quux Value "cc" is present with the following keys: wibble The important bit is that the keys are stored as separate elements in the keys array and that they therefore do not need to be parsed out of a text string. I could do something like declare -A seen seen=() for value in "${hash[@]}"; do if [ -n "${seen[$value]}" ]; then continue fi keys=() for key in "${!hash[@]}"; do if [ "${hash[$key]}" = "$value" ]; then keys+=( "$key" ) fi done printf 'Value "%s" is present with the following keys: %s\n' \ "$value" "${keys[*]}" seen[$value]=1 done But it seems a bit inefficient with that double loop. Is there a piece of array syntax that I've missed for bash? Would doing this in e.g. zsh give me access to more powerful array manipulation tools? In Perl, I would do my %hash = ( 'foo' => 'aa', 'bar' => 'bb', 'baz' => 'aa', 'quux' => 'bb', 'wibble' => 'cc', 'wobble' => 'aa' ); my %keys; while ( my ( $key, $value ) = each(%hash) ) { push( @{ $keys{$value} }, $key ); } foreach my $value ( keys(%keys) ) { printf( "Value \"%s\" is present with the following keys: %s\n", $value, join( " ", @{ $keys{$value} } ) ); } But bash associative arrays can't hold arrays... I'd also be interested in any old school solution possibly using some form of indirect indexing (building a set of index array(s) when reading the values that I said I had in hash above?). It feels like there ought to be a way to do this in linear time.

I saw a trick for implementing associative arrays in a shell script. For example print array["apples"] could be scripted as echo \$array$key where key=apples. However, there was no mention of how to generate the keys to iterate over the array. The only way I could think of was to store the keys in a variable delimited by spaces so I could use a for-loop to iterate over the array. So, is there some other way to store the keys for later use?

In TCL, I have a few arrays whose names have a numeric suffix (i.e., whose names end with a number), like below:

array set ps0 [ list 0 15.885 1 55.43 1 0.254 2 0.227 3 0.177 ]
array set ps1 [ list 0  6.585 1 56.43 1 0.254 2 0.227 3 0.177 ] 
array set ps2 [ list 0 32.485 1 43.13 1 0.254 2 0.227 3 0.177 ]

I need to iterate over these in TCL and get the values, but, no matter what I do to escape the numeric suffix, I cannot get both the array and the contents.  Everything I've tried, such as:

ps$i($i)
"ps$i($i)"

or even using a set like:

set p ps$i

...does not work to get the array with the number index.  I get the error:

Original error: can't read "ps": no such variable

...for all possible combinations.  How can I do this (in TCL)?

A few Bourne-like shells support associative arrays: ksh93 (since 1993), zsh (since 1998), bash (since 2009), though with some differences in behaviour between the 3. A common use is for counting occurrences of some strings. However, I find that things like:

typeset -A count
(( count[$var]++ ))

Don't work for some values of $var and I hear it even constitutes an __*arbitrary command execution* vulnerability__ if the contents of $var is or may be under the control of an attacker. Why is that? What are the problematic values? And how do I work around it?

I made an associative array as follows. To give a few details, the keys refer to specific files because I will be using this array in the context of a larger script (where the directory containing the files will be a getopts argument). declare -A BAMREADS echo "BAMREADS array is initialized" BAMREADS[../data/file1.bam]=33285268 BAMREADS[../data/file2.bam]=28777698 BAMREADS[../data/file3.bam]=22388955 echo ${BAMREADS[@]} # Output: 22388955 33285268 28777698 echo ${!BAMREADS[@]} # Output: ../data/file1.bam ../data/file2.bam ../data/file3.bam So far, this array seems to behave as I expect. Now, I want to build another associative array based on this array. To be specific: my second array will have the same keys as my first one but I want to divide the values by a variable called $MIN. I am not sure which of the following strategies is best and I can't seem to make either work. **Strategy 1**: copy the array and modify the array? MIN=33285268 declare -A BRAMFRACS echo "BAMFRACS array is initialized" BAMFRACS=("${BAMREADS[@]}") echo ${BAMFRACS[@]} # Output: 22388955 33285268 28777698 echo ${!BAMFRACS[@]} # Output: 0 1 2 This is not what I want for the keys. Even if it works, I would then need to perform the operation I mentioned on all the values. **Stragegy 2**: build the second array when looping through the first. MIN=33285268 declare -A BRAMFRACS echo "BAMFRACS array is initialized" for i in $(ls $BAMFILES/*bam) do echo $i echo ${BAMREADS[$i]} BAMFRACS[$i] = ${BAMREADS[$i]} done echo ${BAMFRACS[@]} echo ${!BAMFRACS[@]} #When I run this, I get the following error which I am unsure how to solve: ../data/file1.bam 33285268 script.bash: line 108: BAMFRACS[../data/file1.bam]: No such file or directory ../data/file2.bam 28777698 script.bash: line 108: BAMFRACS[../data/file2.bam]: No such file or directory ../data/file3.bam 22388955 script.bash: line 108: BAMFRACS[../data/file3.bam]: No such file or directory Thanks

How to check if a dictionary (associative array) is empty? I just declare one using declare -A dict. I want to know if it is just declared but not have any key.

I am trying to pass a bash associative array by reference into a function and then be able to see the changed content back in the main script after the function is complete. I have found what seems to be the most straightforward way to do it [here](https://unix.stackexchange.com/a/462089/21348) except in my case the function is being run ***in the background***. It seems that no matter what I do, I can't get the linked solution above to work in this scenario. In the snippet below, I've taken the working example code from the link above and simply added a "&" to the function call and a "wait" on the following line to demonstrate the issue as simply as possible. I suspect bash is trying to prevent the main script and the background function from stepping on each other, but I don't know how to solve it. **Example Code:** foo () { declare -n fooarray="$1" fooarray["fookey"]=foovalue } declare -A myarray myarray["mainkey"]=mainvalue foo myarray & wait for key in "${!myarray[@]}"; do printf '%s = %s\n' "$key" "${myarray[$key]}" done **Output:** bash-4.4$ ./test.sh mainkey = mainvalue Any help would be appreciated. I know I could potentially do silly things like writing the contents of the array out to a file and then parsing it back in, but I'm hoping there's a more elegant solution than that.

I am playing a bit with associative arrays in Bash and I found the following difference when declaring the exact same associative array with and without declare. The code is as follows:

#!/usr/bin/env bash

echo -e "\n\nASSOCIATIVE ARRAY\n"
declare -A MY_MAP=( 
    [Madrid]="Spanish" 
    [London]="English" 
    [Paris]="French" 
    =2
    =3.14 
)
echo "First element: $MY_MAP"
echo "Whole content as single string: ${MY_MAP[*]}"
echo "Whole content quoted separately: ${MY_MAP[@]}"
echo "List of indices: ${!MY_MAP[@]}"
echo "Array length: ${#MY_MAP[*]}"
echo "Array length: ${#MY_MAP[@]}"
echo "Second element: ${MY_MAP[London]}"
echo "Last 2 elements: ${MY_MAP[@]:1:3}"

echo -e "\n\nASSOCIATIVE ARRAY - 2\n"
MY_MAP2=( 
    [Madrid]="Spanish" 
    [London]="English" 
    [Paris]="French" 
    =2
    =3.14 
)
echo "First element: $MY_MAP2"
echo "Whole content as single string: ${MY_MAP2[*]}"
echo "Whole content quoted separately: ${MY_MAP2[@]}"
echo "List of indices: ${!MY_MAP2[@]}"
echo "Array length: ${#MY_MAP2[*]}"
echo "Array length: ${#MY_MAP2[@]}"
echo "Second element: ${MY_MAP2[London]}"
echo "Last 2 elements: ${MY_MAP2[@]:1:3}"

When I execute the previous script I do get the following output:

ASSOCIATIVE ARRAY

First element: 
Whole content as single string: French 3.14 2 English Spanish
Whole content quoted separately: French 3.14 2 English Spanish
List of indices: Paris 3 1 London Madrid
Array length: 5
Array length: 5
Second element: English
Last 2 elements: French 3.14 2


ASSOCIATIVE ARRAY - 2

First element: French
Whole content as single string: French 2 3.14
Whole content quoted separately: French 2 3.14
List of indices: 0 1 3
Array length: 3
Array length: 3
Second element: French
Last 2 elements: 2 3.14

My question is what is declare -A doing that makes the output different? A detailed insight of what is happening here will be appreciated. Thanks a lot in advance.

bash evaluates the following expression without any objections: declare -A SPANISH=( [rojo]=red [verde]=green [azul]=blue ) ...but it does not like this one one bit: declare -A SPANISH=( $( echo "[rojo]=red [verde]=green [azul]=blue" ) ) bash: SPANISH: $( echo "[rojo]=red [verde]=green [azul]=blue" ): must use subscript when assigning associative array I have tried many variations, but the result is always one or more instances of the must use subscript when assigning associative array error shown above. This example is silly, of course. Its only purpose is to illustrate the problem of *initializing a **bash** associative array using a command substitution*. Can this be done? To be concrete, and to continue with the silly example above, what would be a command `` such that declare -A SPANISH=( $( ) ) ...produces the same final result as that produced by declare -A SPANISH=( [rojo]=red [verde]=green [azul]=blue ) above? Incidentally, zsh handles this situation without any problem: $ declare -A SPANISH=( $( echo "rojo red verde green azul blue" ) ) $ echo "${SPANISH[azul]}" blue

I have a file with 4 columns. When I put these 4 columns into an array using NR as the index, the entries are duplicated somehow. See below for an elaboration of the issue. The first 5 lines of the file look like this -bash-4.2$ cat -ve file | head -n 5 chr start end p$ 13 59341171 59343427 1.86642E-18$ 10 72886545 72888679 1.13636E-09$ 16 81900987 81902805 6.79697E-09$ 1 46797890 46800143 2.24436E-08$ I assigned each line as an entry of an array indexed by the NR, then the print out of the array looks like this (using the first 5 lines as an example): -bash-4.2$ awk 'NR for(x in a) > print x, a[x]}' file 1 chr start end p 1 chr start end p 2 13 59341171 59343427 1.86642E-18 1 chr start end p 2 13 59341171 59343427 1.86642E-18 3 10 72886545 72888679 1.13636E-09 4 16 81900987 81902805 6.79697E-09 1 chr start end p 2 13 59341171 59343427 1.86642E-18 3 10 72886545 72888679 1.13636E-09 4 16 81900987 81902805 6.79697E-09 5 1 46797890 46800143 2.24436E-08 1 chr start end p 2 13 59341171 59343427 1.86642E-18 3 10 72886545 72888679 1.13636E-09 I can see that the 5 lines of the file are there, but entries are duplicated a few times. I wonder what the problem is and how to fix it. Thanks in advance.

I have two tab separated files, each with two columns. I want to create a file which contains overlapping elements by column 1 of the two files. To do so, I put file 1 in an array first then scanned the array to check against file 2 for overlaps. However, somehow the index of the array cannot be recognized. See below for the elaboration of the problem. The first 3 lines of the files look like this: File 1: 90001 raw acceleration data 2634 Heavy DIY 1011 Light DIY File 2: 2634 218263 25680 44313 25681 44313 To show that there are overlaps in column 1 of the two files: user@cluster:~> grep 90001 file2 90001 103662 user@cluster:~> grep 2634 file2 2634 218263 To create file 3, I tried this first, which yielded an empty file. awk 'BEGIN {FS = "\t"; OFS= "\t"} NR==FNR {a[$1]=$2; next} { if($1 in a) print $1, a[$1]}' file1 file2 > file3 The following code confirmed the issue is the index of the array was not recognized; because adding the else line actually prints file2 into file3. awk 'BEGIN {FS = "\t"; OFS= "\t"} NR==FNR {a[$1]=$2; next} {if($1 in a) print $1, a[$1] else print $1, $2}' file1 file2 > file3 I am quite puzzled. I wonder what might have caused the issue and how I can fix it? Thanks in advance.

I'm trying to create a summary of how many files in a directory have n number of lines in them. I'm using wc -l * | sort to print out the number of lines against the name of each file. What I'm trying to achieve is a summary of the directory which would produce: 56 5 60 6 3 7 etc, where the first column represents number of files and the second represents number of lines. I've looked at an awk command awk 'END{print NR}' directory/* which returns the number of lines in the entire directory. I have considered a printf solution to format the wc -l output . Any assistance would be greatly greatly appreciated! Thank you

I would like to use some kind of minimalistic template engine with pure bash and envsubst:

user@host:~$ env -i FOO=foo BAR="bar baz" envsubst '$FOO,$BAR' \
  Reason: set -x shows that the argument for env becomes one giant string:

sh + env -i 'FOO='\''foo'\''' 'BAR='\''bar' 'baz'\''' envsubst #... env: ‘baz'’: No such file or directory ``` I must have missed a shell escape lession (again...). How might I rewrite last example to work properly?

# SETUP PHP81 SYMLINKS declare -A cgi=([path]="/opt/remi/php81/root/usr/bin/php-cgi" [filename]="php-cgi81") declare -A config=([path]="/opt/remi/php81/root/usr/bin/php-config" [filename]="php-config81") declare -A phpize=([path]="/opt/remi/php81/root/usr/bin/phpize" [filename]="phpize81") declare -A pecl=([path]="/opt/remi/php81/root/usr/bin/pecl" [filename]="pecl81") declare -A pear=([path]="/opt/remi/php81/root/usr/bin/pear" [filename]="pear81") declare -a symlinks=("cgi" "config" "phpize" "pecl" "pear") echo -en "[INFO]: Setting up PHP 8.1 symlinks\n" cd /usr/bin for symlink in "${symlinks[@]}"; do echo -en "[INFO]: Creating symlink for ${symlink}\n" # Get the array that matches the string in symlink props="$symlink[@]" # Print out the filename property eg cgi[filename], config[filename], phpize[filename] echo ${!props[filename]} echo -en "\n" done There is the section of code giving me issues. It currently outputs ./upgrade.sh php-cgi81 /opt/remi/php81/root/usr/bin/php-cgi php-config81 /opt/remi/php81/root/usr/bin/php-config phpize81 /opt/remi/php81/root/usr/bin/phpize pecl81 /opt/remi/php81/root/usr/bin/pecl pear81 /opt/remi/php81/root/usr/bin/pear The expected output is ./upgrade.sh php-cgi8= php-config81 phpize81 pecl81 pear81 This is now solved I posted the solution below but someone down voted it because they dislike my solution but the solution I posted is working. But you decide what you want to use. Thanks for the help.

Does awk use separate chaining, open addressing or does it have its own way of handling collisions in a hashmap? Do gawk and nawk implement the same algorithm? Thank you.