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Is there any way to pipe the output of a command which lists a bunch of numbers (each number in a separate line) and initialize a bash array with those numbers?
Details: This lists 3 changelist numbers which have been submitted in the following date range. The output is then piped to cut to filter it further to get just the changelist numbers.
p4 changes -m 3 -u edk -s submitted @2009/05/01,@now | cut -d ' ' -f 2 E.g. :
422311 543210 444000 How is it possible to store this list in a bash array?
930
To initialise array with elements in Bash, use assignment operator = , and enclose all the elements inside braces () separated by spaces in between them. We may also specify the index for each element in the array.
Generally, containers (such as arrays) in computer programming are used to store inputs and work-in-progress; once something has been “output”, it's usually no-longer necessary to have it stored in RAM. If you need to store it long-term, output it to a file instead of to a container in RAM.
bash [filename] runs the commands saved in a file. $@ refers to all of a shell script's command-line arguments. $1 , $2 , etc., refer to the first command-line argument, the second command-line argument, etc. Place variables in quotes if the values might have spaces in them.
You can execute the command under ticks and set the Array like,
ARRAY=(`command`) Alternatively, you can save the output of the command to a file and cat it similarly,
command > file.txt ARRAY=(`cat file.txt`) Or, simply one of the following forms suggested in the comments below,
ARRAY=(`< file.txt`) ARRAY=($(<file.txt)) If you use bash 4+, it has special command for this: mapfile also known as readarray, so you can fill your array like this:
declare -a a readarray -t a < <(command) for more portable version you can use
declare -a a while read i; do a=( "${a[@]}" "$i" ) done < <(command) If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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