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

打印三

#!/bin/bash

string="a | b c"
pattern=' | '

# replaces pattern with newlines
splitted="$(sed "s/$pattern/\n/g" <<< "$string")"

# Reads lines and put them in array
readarray -t array2 <<< "$splitted"

# Prints number of elements
echo ${#array2[@]}
# Prints all elements
for a in "${array2[@]}"; do
        echo "> '$a'"
done

此解决方案适用于较大的分隔符(多个字符)。 如果在原始字符串中已经有换行符，则不工作

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

IFS=', ' read -r -a array <<< "$string"

请注意，$IFS中的字符被单独视为分隔符，因此在这种情况下，字段可以用逗号或空格分隔，而不是两个字符的序列。但有趣的是，当输入中出现逗号时，不会创建空字段，因为空格是经过特殊处理的。

要访问单个元素:

echo "${array[0]}"

要遍历元素:

for element in "${array[@]}"
do
    echo "$element"
done

要同时获取索引和值:

for index in "${!array[@]}"
do
    echo "$index ${array[index]}"
done

最后一个示例很有用，因为Bash数组很稀疏。换句话说，您可以删除一个元素或添加一个元素，然后索引不是连续的。

unset "array[1]"
array[42]=Earth

获取数组中元素的个数:

echo "${#array[@]}"

如上所述，数组可以是稀疏的，所以不应该使用长度来获取最后一个元素。以下是在Bash 4.2及以后版本中可以做到的:

echo "${array[-1]}"

在任何版本的Bash中(从2.05b之后的某个地方):

echo "${array[@]: -1:1}"

较大的负偏移量选择距离数组末端更远的位置。注意旧形式中负号前面的空格。这是必须的。

这类似于Jmoney38的方法，但是使用sed:

string="1,2,3,4"
array=(`echo $string | sed 's/,/\n/g'`)
echo ${array[0]}

打印1

当我想解析一个输入时，我看到了这篇文章: word1 word2,…

以上这些对我都没有帮助。使用awk解决了这个问题。如果它能帮助某人:

STRING="value1,value2,value3"
array=`echo $STRING | awk -F ',' '{ s = $1; for (i = 2; i <= NF; i++) s = s "\n"$i; print s; }'`
for word in ${array}
do
        echo "This is the word $word"
done