t="one,two,three"
a=($(echo "$t" | tr ',' '\n'))
echo "${a[2]}"

打印三

另一种方法是:

str="a, b, c, d"  # assuming there is a space after ',' as in Q
arr=(${str//,/})  # delete all occurrences of ','

在这个'arr'后面是一个包含四个字符串的数组。 这不需要处理IFS或读取或任何其他特殊的东西，因此更简单和直接。

接受的答案适用于一行中的值。如果变量有几行:

string='first line
        second line
        third line'

我们需要一个非常不同的命令来获取所有的行:

While read -r line;做线+ =(“美元线”);完成了< < <字符串" $ "

或者更简单的bash readarray:

readarray -t lines <<<"$string"

利用printf特性很容易打印所有行:

printf ">[%s]\n" "${lines[@]}"

>[first line]
>[        second line]
>[        third line]

试试这个

IFS=', '; array=(Paris, France, Europe)
for item in ${array[@]}; do echo $item; done

这很简单。如果你想，你也可以添加一个声明(并删除逗号):

IFS=' ';declare -a array=(Paris France Europe)

添加IFS是为了撤销上述操作，但在新的bash实例中，它可以在没有IFS的情况下工作

这是我的破解方法!

使用bash拆分字符串是一件非常无聊的事情。实际情况是，我们有有限的方法，只能在少数情况下工作(被“;”，“/”，“.”等等分开)，或者我们在输出中有各种副作用。

下面的方法需要一些操作，但我相信它可以满足我们的大部分需求!

#!/bin/bash

# --------------------------------------
# SPLIT FUNCTION
# ----------------

F_SPLIT_R=()
f_split() {
    : 'It does a "split" into a given string and returns an array.

    Args:
        TARGET_P (str): Target string to "split".
        DELIMITER_P (Optional[str]): Delimiter used to "split". If not 
    informed the split will be done by spaces.

    Returns:
        F_SPLIT_R (array): Array with the provided string separated by the 
    informed delimiter.
    '

    F_SPLIT_R=()
    TARGET_P=$1
    DELIMITER_P=$2
    if [ -z "$DELIMITER_P" ] ; then
        DELIMITER_P=" "
    fi

    REMOVE_N=1
    if [ "$DELIMITER_P" == "\n" ] ; then
        REMOVE_N=0
    fi

    # NOTE: This was the only parameter that has been a problem so far! 
    # By Questor
    # [Ref.: https://unix.stackexchange.com/a/390732/61742]
    if [ "$DELIMITER_P" == "./" ] ; then
        DELIMITER_P="[.]/"
    fi

    if [ ${REMOVE_N} -eq 1 ] ; then

        # NOTE: Due to bash limitations we have some problems getting the 
        # output of a split by awk inside an array and so we need to use 
        # "line break" (\n) to succeed. Seen this, we remove the line breaks 
        # momentarily afterwards we reintegrate them. The problem is that if 
        # there is a line break in the "string" informed, this line break will 
        # be lost, that is, it is erroneously removed in the output! 
        # By Questor
        TARGET_P=$(awk 'BEGIN {RS="dn"} {gsub("\n", "3F2C417D448C46918289218B7337FCAF"); printf $0}' <<< "${TARGET_P}")

    fi

    # NOTE: The replace of "\n" by "3F2C417D448C46918289218B7337FCAF" results 
    # in more occurrences of "3F2C417D448C46918289218B7337FCAF" than the 
    # amount of "\n" that there was originally in the string (one more 
    # occurrence at the end of the string)! We can not explain the reason for 
    # this side effect. The line below corrects this problem! By Questor
    TARGET_P=${TARGET_P%????????????????????????????????}

    SPLIT_NOW=$(awk -F"$DELIMITER_P" '{for(i=1; i<=NF; i++){printf "%s\n", $i}}' <<< "${TARGET_P}")

    while IFS= read -r LINE_NOW ; do
        if [ ${REMOVE_N} -eq 1 ] ; then

            # NOTE: We use "'" to prevent blank lines with no other characters 
            # in the sequence being erroneously removed! We do not know the 
            # reason for this side effect! By Questor
            LN_NOW_WITH_N=$(awk 'BEGIN {RS="dn"} {gsub("3F2C417D448C46918289218B7337FCAF", "\n"); printf $0}' <<< "'${LINE_NOW}'")

            # NOTE: We use the commands below to revert the intervention made 
            # immediately above! By Questor
            LN_NOW_WITH_N=${LN_NOW_WITH_N%?}
            LN_NOW_WITH_N=${LN_NOW_WITH_N#?}

            F_SPLIT_R+=("$LN_NOW_WITH_N")
        else
            F_SPLIT_R+=("$LINE_NOW")
        fi
    done <<< "$SPLIT_NOW"
}

# --------------------------------------
# HOW TO USE
# ----------------

STRING_TO_SPLIT="
 * How do I list all databases and tables using psql?

\"
sudo -u postgres /usr/pgsql-9.4/bin/psql -c \"\l\"
sudo -u postgres /usr/pgsql-9.4/bin/psql <DB_NAME> -c \"\dt\"
\"

\"
\list or \l: list all databases
\dt: list all tables in the current database
\"

[Ref.: https://dba.stackexchange.com/questions/1285/how-do-i-list-all-databases-and-tables-using-psql]


"

f_split "$STRING_TO_SPLIT" "bin/psql -c"

# --------------------------------------
# OUTPUT AND TEST
# ----------------

ARR_LENGTH=${#F_SPLIT_R[*]}
for (( i=0; i<=$(( $ARR_LENGTH -1 )); i++ )) ; do
    echo " > -----------------------------------------"
    echo "${F_SPLIT_R[$i]}"
    echo " < -----------------------------------------"
done

if [ "$STRING_TO_SPLIT" == "${F_SPLIT_R[0]}bin/psql -c${F_SPLIT_R[1]}" ] ; then
    echo " > -----------------------------------------"
    echo "The strings are the same!"
    echo " < -----------------------------------------"
fi

输入代码here多字符分隔符解决方案。

正如其他人在这篇文章中指出的，OP的问题给出了一个用逗号分隔的字符串被解析成数组的例子，但没有指出他/她是否只对逗号分隔符、单字符分隔符或多字符分隔符感兴趣。

由于谷歌倾向于将这个答案排在搜索结果的顶部或附近，所以我想为读者提供一个关于多个字符分隔符问题的有力答案，因为至少有一个回答也提到了这个问题。

如果您正在寻找多字符分隔符问题的解决方案，我建议您查看Mallikarjun M的帖子，特别是来自gniourf_gniourf的回复 谁提供了这个优雅的纯BASH解决方案使用参数展开:

#!/bin/bash
str="LearnABCtoABCSplitABCaABCString"
delimiter=ABC
s=$str$delimiter
array=();
while [[ $s ]]; do
    array+=( "${s%%"$delimiter"*}" );
    s=${s#*"$delimiter"};
done;
declare -p array

链接到引用的评论/引用的帖子

链接到引用的问题:如何在bash中拆分多字符分隔符上的字符串?

2022年8月3日

Xebeche在下面的评论中提出了一个很好的观点。在审查了他们建议的编辑之后，我修改了gniourf_gniourf提供的脚本，并添加了注释，以便于理解脚本正在做什么。我还将双括号[[]]改为单括号，以提高兼容性，因为许多SHell变体不支持双括号表法。在本例中，对于BaSH，逻辑在单括号或双括号内工作。

#!/bin/bash
  
str="LearnABCtoABCSplitABCABCaABCStringABC"
delimiter="ABC"
array=()

while [ "$str" ]; do

    # parse next sub-string, left of next delimiter
    substring="${str%%"$delimiter"*}" 

    # when substring = delimiter, truncate leading delimiter
    # (i.e. pattern is "$delimiter$delimiter")
    [ -z "$substring" ] && str="${str#"$delimiter"}" && continue

    # create next array element with parsed substring
    array+=( "$substring" )

    # remaining string to the right of delimiter becomes next string to be evaluated
    str="${str:${#substring}}"

    # prevent infinite loop when last substring = delimiter
    [ "$str" == "$delimiter" ] && break

done

declare -p array

不加评论:

#!/bin/bash
str="LearnABCtoABCSplitABCABCaABCStringABC"
delimiter="ABC"
array=()
while [ "$str" ]; do
    substring="${str%%"$delimiter"*}" 
    [ -z "$substring" ] && str="${str#"$delimiter"}" && continue
    array+=( "$substring" )
    str="${str:${#substring}}"
    [ "$str" == "$delimiter" ] && break
done
declare -p array