CODEWITHSUNDEEP
arraysbashnewlinepipe
splicer
splicer

Reputation: 5404

How can I use a Bash array as input to a command?

Say, for example, I have the following array:

files=( "foo" "bar" "baz fizzle" )

I want to pipe the contents of this array through a command, say sort, as though each element where a line in a file. Sure, I could write the array to a temporary file, then use the temporary file as input to sort, but I'd like to avoid using a temporary file if possible.

If "bar fizzle" didn't have that space character, I could do something like this:

echo ${files[@]} | tr ' ' '\012' | sort

Any ideas? Thanks!

Upvotes: 9

Views: 8399

Answers (5)

Samuel Neff
Samuel Neff

Reputation: 74949

I like to wrap common items like this into function to make it easier to understand what's going on:

pipeArray() {
    for ITEM in $@; do
        echo "$ITEM"
    done
}

DATA=('a' 'c' 'b')
pipeArray ${DATA[@]} | sort

Upvotes: 1

kurt
kurt

Reputation: 21

For sorting files I would recommend sorting in zero-terminated mode (to avoid errors in case of embedded newlines in file names or paths):

files=(
$'fileNameWithEmbeddedNewline\n.txt'
$'saneFileName.txt'
)

echo ${#files[@]}

sort <(for f in "${files[@]}" ; do printf '%s\n' "$((i+=1)): $f" ; done)
sort -z <(for f in "${files[@]}" ; do printf '%s\000' "$((i+=1)): $f" ; done) | tr '\0' '\n'

printf "%s\000" "${files[@]}" | sort -z | tr '\0' '\n'
find . -type f -print0 | sort -z | tr '\0' '\n'

sort -z reads & writes zero-terminated lines!

Upvotes: 2

Gordon Davisson
Gordon Davisson

Reputation: 126088

Yet another solution:

printf "%s\n" "${files[@]}" | sort

Upvotes: 7

Tomasz Elendt
Tomasz Elendt

Reputation: 1485

SAVE_IFS=$IFS
IFS=$'\n'
echo "${files[*]}" | sort
IFS=$SAVE_IFS

Of course it won't work properly if there are any newlines in array values.

Upvotes: 3

Ignacio Vazquez-Abrams
Ignacio Vazquez-Abrams

Reputation: 799510

sort <(for f in "${files[@]}" ; do echo "$f" ; done)

Upvotes: 11

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