I have four cameras and want to store output from any of it in empty array and get output code from any array member.
# streams to check
streams=("rtsp://Streaming/Channels/01" "rtsp://Streaming/Channels/201" "rtsp://Streaming/Channels/301" "rtsp://Streaming/Channels/401")
# declare array for stream codes
declare -a outputcodes
for stream in "${streams[#]}"; do
streamoutput=$(timeout 20s ffprobe -v quiet -print_format json -show_streams $stream)
# get output code for each stream
streamresults=$(jq -r '.streams[0].index' <<< "$streamoutput")
# add stream result to array
outputcodes+=$streamresults
done
exit 0
# get first array member result
echo ${outputcodes[0]}
the problem is that echo ${outputcodes[0]} echo ${outputcodes} shows nothing
What's the problem ?
when i add echo $streamresults to for loop i'm getting correct results
0
0
0
0
setting outputcodes+=($streamresults) changes nothing
Bash version:4.2.46(2)-release
Tried to declare array in this way but same output:
declare -a outputcodes=()
I'm an idiot, had exit 0 before echoing array, once removed it all works.
Sorry for bothering
Related
This question already has answers here:
Reading output of a command into an array in Bash
(4 answers)
Closed 1 year ago.
I'm new to bash scripting and trying to learn.
I have a variable $temp, that contains what I get from an API call, which is a long list of SHA1 hashes. I want to take what is in $temp and create an array that I can loop through and compare each entry to a string I have defined. Somehow, I can not seem to get it to work. The array I create always only contains only one element. It is like the rest of the string in $temp is being ignored.
I have tried multiple approaches, and can't get anything working the way I want it to.
Here's the code snippet:
temp=$(curl --silent --request GET "https://api.pwnedpasswords.com/range/$shortendHash")
echo "Temp is: $temp"
declare -A myArr
read myArr <<<$temp
echo ${myArr[#]}
echo ${myArr[0]}
echo ${myArr[1]}
When I run this, I get a full list of hashes, when I echo $temp (line 2), something like this:
"Temp is: 002C3CADF9FC86069F09961B10E0EDEFC45:1
003BE35BD9466D19258E79C8665AFB072F6:1
0075B2ADF782F9677BDDF8CC5778900D986:8
00810352C02B145FF304FCBD5BEF4F7AA9F:1
013720F40B99D6BCF6F08BD7271523EBB49:1
01C894A55EBCB6048A745B37EC2D989F102:1
030B46D53696C8889910EE0F9EB42CEAE97:4
03126B56153F0564F4A6ED6E734604C67E8:2
043196099707FCB0C01F8C2111086A92A0B:1
0452CABBEF8438F358F0BD8089108D0910E:5
0490255B206A2C0377EBD080723BF72DDAE:2
05AD1141C41237E061460DB5CA5412C1A48:4
05C1D058E4439F8F005EFB32E7553E6AA5B:1
067AF515CC712AC4ACA012311979DBC7C9A:2 ... and so on.."
But the
echo ${myArr[#]}
echo ${myArr[0]}
echo ${myArr[1]}
returns (first value is ${myArr[#]}, second is ${myArr[0]}, and last one is an empty line, indicating that there is no value at array position 1):
002C3CADF9FC86069F09961B10E0EDEFC45:1
002C3CADF9FC86069F09961B10E0EDEFC45:1
I hope someone can help with this.
Thanks a lot in advance!
declare -A myArr # creates an associative array (hash)
declare -a myArr # creates an array
Neither is necessary here. read can create the array for you. See help declare and help read.
temp=$(curl --silent --request GET "https://api.pwnedpasswords.com/range/$shortendHash")
# -a: assign the words read to sequential indices of the array
read -a myArr <<<"$temp"
declare -p myArr
Output:
declare -a myArr=([0]="002C3CADF9FC86069F09961B10E0EDEFC45:1" [1]="003BE35BD9466D19258E79C8665AFB072F6:1" [2]="0075B2ADF782F9677BDDF8CC5778900D986:8" [3]="00810352C02B145FF304FCBD5BEF4F7AA9F:1" [4]="013720F40B99D6BCF6F08BD7271523EBB49:1" [5]="01C894A55EBCB6048A745B37EC2D989F102:1" [6]="030B46D53696C8889910EE0F9EB42CEAE97:4" [7]="03126B56153F0564F4A6ED6E734604C67E8:2" [8]="043196099707FCB0C01F8C2111086A92A0B:1" [9]="0452CABBEF8438F358F0BD8089108D0910E:5" [10]="0490255B206A2C0377EBD080723BF72DDAE:2" [11]="05AD1141C41237E061460DB5CA5412C1A48:4" [12]="05C1D058E4439F8F005EFB32E7553E6AA5B:1" [13]="067AF515CC712AC4ACA012311979DBC7C9A:2")
Assuming ...
$(curl --silent --request GET "https://api.pwnedpasswords.com/range/$shortendHash")
Returns ...
002C3CADF9FC86069F09961B10E0EDEFC45:1
003BE35BD9466D19258E79C8665AFB072F6:1
0075B2ADF782F9677BDDF8CC5778900D986:8
00810352C02B145FF304FCBD5BEF4F7AA9F:1
013720F40B99D6BCF6F08BD7271523EBB49:1
01C894A55EBCB6048A745B37EC2D989F102:1
030B46D53696C8889910EE0F9EB42CEAE97:4
03126B56153F0564F4A6ED6E734604C67E8:2
043196099707FCB0C01F8C2111086A92A0B:1
0452CABBEF8438F358F0BD8089108D0910E:5
0490255B206A2C0377EBD080723BF72DDAE:2
05AD1141C41237E061460DB5CA5412C1A48:4
05C1D058E4439F8F005EFB32E7553E6AA5B:1
067AF515CC712AC4ACA012311979DBC7C9A:2
Then assign this to an array by wrapping in a set of parens:
# unset current variable
$ unset myArr
# no need to issue a `declare`; the `myArr=( ... )` will automatically create `myArr` as a normal integer-indexed array
$ myArr=( $(curl --silent --request GET "https://api.pwnedpasswords.com/range/$shortendHash") )
# verify array contents:
$ typeset myArr
declare -a myarr=([0]="002C3CADF9FC86069F09961B10E0EDEFC45:1" [1]="003BE35BD9466D19258E79C8665AFB072F6:1" [2]="0075B2ADF782F9677BDDF8CC5778900D986:8" [3]="00810352C02B145FF304FCBD5BEF4F7AA9F:1" [4]="013720F40B99D6BCF6F08BD7271523EBB49:1" [5]="01C894A55EBCB6048A745B37EC2D989F102:1" [6]="030B46D53696C8889910EE0F9EB42CEAE97:4" [7]="03126B56153F0564F4A6ED6E734604C67E8:2" [8]="043196099707FCB0C01F8C2111086A92A0B:1" [9]="0452CABBEF8438F358F0BD8089108D0910E:5" [10]="0490255B206A2C0377EBD080723BF72DDAE:2" [11]="05AD1141C41237E061460DB5CA5412C1A48:4" [12]="05C1D058E4439F8F005EFB32E7553E6AA5B:1" [13]="067AF515CC712AC4ACA012311979DBC7C9A:2")
Assuming OP wants to populate the array from the variable $temp, and assuming the white space in $temp consists of linefeeds and not spaces:
$ mapfile -t myArr <<< "${temp}"
$ typeset -p myArr
declare -a x=([0]="002C3CADF9FC86069F09961B10E0EDEFC45:1" [1]="003BE35BD9466D19258E79C8665AFB072F6:1" [2]="0075B2ADF782F9677BDDF8CC5778900D986:8" [3]="00810352C02B145FF304FCBD5BEF4F7AA9F:1" [4]="013720F40B99D6BCF6F08BD7271523EBB49:1" [5]="01C894A55EBCB6048A745B37EC2D989F102:1" [6]="030B46D53696C8889910EE0F9EB42CEAE97:4" [7]="03126B56153F0564F4A6ED6E734604C67E8:2" [8]="043196099707FCB0C01F8C2111086A92A0B:1" [9]="0452CABBEF8438F358F0BD8089108D0910E:5" [10]="0490255B206A2C0377EBD080723BF72DDAE:2" [11]="05AD1141C41237E061460DB5CA5412C1A48:4" [12]="05C1D058E4439F8F005EFB32E7553E6AA5B:1" [13]="067AF515CC712AC4ACA012311979DBC7C9A:2")
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.
This question already has answers here:
A variable modified inside a while loop is not remembered
(8 answers)
Closed 6 years ago.
I have a pretty simple sh script where I make a system cat call, collect the results and parse some relevant information before storing the information in an array, which seems to work just fine. But as soon as I exit the for loop where I store the information, the array seems to clear itself. I'm wondering if I am accessing the array incorrectly outside of the for loop. Relevant portion of my script:
#!/bin/sh
declare -a QSPI_ARRAY=()
cat /proc/mtd | while read mtd_instance
do
# split result into individiual words
words=($mtd_instance)
for word in "${words[#]}"
do
# check for uboot
if [[ $word == *"uboot"* ]]
then
mtd_num=${words[0]}
index=${mtd_num//[!0-9]/} # strip everything except the integers
QSPI_ARRAY[$index]="uboot"
echo "QSPI_ARRAY[] at index $index: ${QSPI_ARRAY[$index]}"
elif [[ $word == *"fpga_a"* ]]
then
echo "found it: "$word""
mtd_num=${words[0]}
index=${mtd_num//[!0-9]/} # strip everything except the integers
QSPI_ARRAY[$index]="fpga_a"
echo "QSPI_ARRAY[] at index $index: ${QSPI_ARRAY[$index]}"
# other items are added to the array, all successfully
fi
done
echo "length of array: ${#QSPI_ARRAY[#]}"
echo "----------------------"
done
My output is great until I exit the for loop. While within the for loop, the array size increments and I can check that the item has been added. After the for loop is complete I check the array like so:
echo "RESULTING ARRAY:"
echo "length of array: ${#QSPI_ARRAY[#]}"
for qspi in "${QSPI_ARRAY}"
do
echo "qspi instance: $qspi"
done
Here are my results, echod to my display:
dev: size erasesize name
length of array: 0
-------------
mtd0: 00100000 00001000 "qspi-fsbl-uboot"
QSPI_ARRAY[] at index 0: uboot
length of array: 1
-------------
mtd1: 00500000 00001000 "qspi-fpga_a"
QSPI_ARRAY[] at index 1: fpga_a
length of array: 2
-------------
RESULTING ARRAY:
length of array: 0
qspi instance:
EDIT: After some debugging, it seems I have two different arrays here somehow. I initialized the array like so: QSPI_ARRAY=("a" "b" "c" "d" "e" "f" "g"), and after my for-loop for parsing the array it is still a, b, c, etc. How do I have two different arrays of the same name here?
This structure:
cat /proc/mtd | while read mtd_instance
do
...
done
Means that whatever comes between do and done cannot have any effects inside the shell environment that are still there after the done.
The fact that the while loop is on the right hand side of a pipe (|) means that it runs in a subshell. Once the loop exits, so does the subshell. And all of its variable settings.
If you want a while loop which makes changes that stick around, don't use a pipe. Input redirection doesn't create a subshell, and in this case, you can just read from the file directly:
while read mtd_instance
do
...
done </proc/mtd
If you had a more complicated command than a cat, you might need to use process substitution. Still using cat as an example, that looks like this:
while read mtd_instance
do
...
done < <(cat /proc/mtd)
In the specific case of your example code, I think you could simplify it somewhat, perhaps like this:
#!/usr/bin/env bash
QSPI_ARRAY=()
while read -a words; do␣
declare -i mtd_num=${words[0]//[!0-9]/}
for word in "${words[#]}"; do
for type in uboot fpga_a; do
if [[ $word == *$type* ]]; then
QSPI_ARRAY[mtd_num]=$type
break 2
fi
done
done
done </proc/mtd
Is this potentially what you are seeing:
http://mywiki.wooledge.org/BashFAQ/024
The think is that I want to save something to an array in bash. The point is that I want one name of file for one array. So I don't know how much arrays I will have.
#!/bin/bash
declare -A NAMES
index=0
for a in recursive.o timeout.o print_recursive.o recfun.o
do
NAMES[$index]=$a
index=$((index+1))
echo ${NAMES[ $index ]}
done
When I run script with -x I can see that NAMES[$index], the index is not there represented as number so the whole thing doesn't work.
The error is at lines 7 and 8. Swap them and it will work.
When index have value 0 you set NAMES[0]=recursive.o, then increment index and print NAMES[1] which not set. And same thing for another elements. Because that there is no output.
Your loop should looks like this:
for a in recursive.o timeout.o print_recursive.o recfun.o
do
NAMES[$index]=$a
echo ${NAMES[$index]}
index=$((index+1))
done
The problem is in the following:
declare -A NAMES
This makes an associative array NAMES. Quoting from help declare:
Options which set attributes:
-a to make NAMEs indexed arrays (if supported)
-A to make NAMEs associative arrays (if supported)
You needed to say:
declare -a NAMES
May be you are trying to do this:
#!/bin/bash
declare -a NAMES
for a in recursive.o timeout.o print_recursive.o recfun.o; do
NAMES+=( "$a" )
done
for (( x=0; x<${#NAMES[#]}; x++ )); do
echo "Index:$x has Value:${NAMES[x]}"
done
Output:
Index:0 has Value:recursive.o
Index:1 has Value:timeout.o
Index:2 has Value:print_recursive.o
Index:3 has Value:recfun.o
Accessing the index which is not set is throwing it off.
NAMES[$index]=$a #Setting up an array with index 0
index=$((index+1)) #Incrementing the index to 1
echo ${NAMES[ $index ]} #Accessing value of index 1 which is not yet set
I'm interested in updating an array element value within a for loop, but my update definition is wrong, since the output contain [counter].
Here is the code I have:
declare -a mem_set=(0 0 0 0 0 0 0)
counter=0
for i in "${domain_path[#]}"
do
cd $i
echo "$(pwd)"
for mLine in $(grep 'default.default.minmaxmemory.main' start_params.properties)
do
echo "$mLine"
done
l_bound="Xmx"
r_bound="m"
mem_set[counter]=$(echo "$mLine" | sed -e "s/.*${l_bound}//;s/${r_bound}.*//")
echo "$mem_set[counter]"
let counter=counter+1
done
The loop and the $(echo "$mLine" | sed -e "s/.*${l_bound}//;s/${r_bound}.*//") run fine, but I can't manage to get the right output. What is my update statement is missing? The output of it is 2048[counter]. Also, instead of using another counter counter in addition to i, is it possible to use i for mem_set array as well (both arrays have the same size)?
Thank you
Since feature requests to mark a comment as an answer remain declined, I copy the above solution here.
can you change echo "$mem_set[counter]" to echo "${mem_set[counter]}" and see if that prints out the right value? – 1_CR
thank you for your suggestion. Changing the format worked, so now I get the right output. – Simply_Me
In bash, you would access a variable with $.
Try,
counter=`expr $counter + 1`
or
counter=$(( counter + 1 ))