如果我在Bash中有一个这样的数组:
FOO=( a b c )
如何用逗号连接元素?例如,生成a b c。
如果我在Bash中有一个这样的数组:
FOO=( a b c )
如何用逗号连接元素?例如,生成a b c。
当前回答
顶部答案的简短版本:
joinStrings() { local a=("${@:3}"); printf "%s" "$2${a[@]/#/$1}"; }
用法:
joinStrings "$myDelimiter" "${myArray[@]}"
其他回答
我将数组作为字符串回显,然后将空格转换为换行,然后使用粘贴将所有内容连接到一行,如下所示:
tr " " "\n" <<< "$FOO" |粘贴-sd, -
结果:
a, b, c
对我来说,这似乎是最快最干净的!
我的尝试。
$ array=(one two "three four" five)
$ echo "${array[0]}$(printf " SEP %s" "${array[@]:1}")"
one SEP two SEP three four SEP five
不使用外部命令:
$ FOO=( a b c ) # initialize the array
$ BAR=${FOO[@]} # create a space delimited string from array
$ BAZ=${BAR// /,} # use parameter expansion to substitute spaces with comma
$ echo $BAZ
a,b,c
警告,它假设元素没有空格。
这个特别适用于busybox的sh和$@:
$ FOO=(a b c)
$ printf '%s\n' "${FOO[@]}" | paste -sd,
a,b,c
Or:
join_by() {
local d=$1
shift
printf '%s\n' "$@" | paste -sd "$d"
}
join_by , "${FOO[@]}" # a,b,c
感谢@gniourf_gniourf对我迄今为止的最佳世界组合的详细评论。很抱歉发布的代码没有完全设计和测试。这是一个更好的尝试。
# join with separator
join_ws() { local d=$1 s=$2; shift 2 && printf %s "$s${@/#/$d}"; }
这种概念上的美是
(still) 100% pure bash ( thanks for explicitly pointing out that printf is a builtin as well. I wasn't aware about this before ... ) works with multi-character delimiters more compact and more complete and this time carefully thought over and long-term stress-tested with random substrings from shell scripts amongst others, covering use of shell special characters or control characters or no characters in both separator and / or parameters, and edge cases, and corner cases and other quibbles like no arguments at all. That doesn't guarantee there is no more bug, but it will be a little harder challenge to find one. BTW, even the currently top voted answers and related suffer from such things like that -e bug ...
附加的例子:
$ join_ws '' a b c
abc
$ join_ws ':' {1,7}{A..C}
1A:1B:1C:7A:7B:7C
$ join_ws -e -e
-e
$ join_ws $'\033[F' $'\n\n\n' 1. 2. 3. $'\n\n\n\n'
3.
2.
1.
$ join_ws $
$