23 March 2008

iterating through an array in bash

Every now and then I need to iterate through an array of items in a bash script, and I can never remember the syntax--I always have to look it up. So here's a quick example...

#!/bin/bash

things=( first second third )

for i in ${things[@]}
do
  echo $i
done


If the number of array elements is large, it can be useful to have one element per line:

things=( \
first \
second \
third \
)
at

3 comments:

  1. Sam4:23 PM

    If you want to loop through an array literally you can do it like this:

    for i in file1 file2 file3
    do
    ...
    done

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  2. macmadness863:58 PM

    thanks for documenting syntax. I wish I knew what the @ sign is doing. is the another variable indicator like $?

    anyway I plan to write a script to remove my log and aux files after compiling a xelatex document.

    ReplyDelete
  3. mbrisby4:29 PM

    The @ symbol is an array subscript which causes the word (things[@]) to expand to all members of the things array. (See the "Arrays" section of the bash man page.)

    ReplyDelete