这是我尝试过的：
n=0
for i in aaa bbb ccc; do
array${i}[$n]=$(date "+%N")
((++n))
done
n=0
for i in aaa bbb ccc; do
echo ${array${i}[$n]}
((++n))
done
任何想法如何使动态数组名称起作用？多谢！
问问题
10547 次
3 回答
5
您可以使用间接扩展：
#!/bin/bash
# create the arrays
n=0
for i in aaa bbb ccc; do
let array$i[$n]=$(date "+%N")
((++n))
done
# display what we did
n=0
for i in aaa bbb ccc; do
var=array$i[$n]
echo ${!var}
((++n))
done
请注意，这只会创建数组变量arrayaaa[0]，arraybbb[1]和arrayccc[2]，而不是（如您所料）arrayaaa[0]，arrayaaa[1]，arrayaaa[2]，arraybbb[0]、arraybbb[1]、arraybbb[2]、arrayccc[0]、arrayccc[1]和arrayccc[2]。
于 2013-05-13T14:47:11.190 回答
4
这就是创建动态命名变量的方式（bash 版本 < 4.3）。
# Dynamically named array
my_variable_name="dyn_arr_names"
eval $my_variable_name=\(\)
# Adding by index to the array eg. dyn_arr_names[0]="bob"
eval $my_variable_name[0]="bob"
# Adding by pushing onto the array eg. dyn_arr_names+=(robert)
eval $my_variable_name+=\(robert\)
# Print value stored at index indirect
echo ${!my_variable_name[0]}
# Print value stored at index
eval echo \${$my_variable_name[0]}
# Get item count
eval echo \${#$my_variable_name[@]}
下面是一组可用于管理动态命名数组的函数（bash 版本 < 4.3）。
# Dynamically create an array by name
function arr() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable" 1>&2 ; return 1 ; }
# The following line can be replaced with 'declare -ag $1=\(\)'
# Note: For some reason when using 'declare -ag $1' without the parentheses will make 'declare -p' fail
eval $1=\(\)
}
# Insert incrementing by incrementing index eg. array+=(data)
function arr_insert() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable" 1>&2 ; return 1 ; }
declare -p "$1" > /dev/null 2>&1
[[ $? -eq 1 ]] && { echo "Bash variable [${1}] doesn't exist" 1>&2 ; return 1 ; }
eval $1[\$\(\(\${#${1}[@]}\)\)]=\$2
}
# Update an index by position
function arr_set() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable" 1>&2 ; return 1 ; }
declare -p "$1" > /dev/null 2>&1
[[ $? -eq 1 ]] && { echo "Bash variable [${1}] doesn't exist" 1>&2 ; return 1 ; }
eval ${1}[${2}]=\${3}
}
# Get the array content ${array[@]}
function arr_get() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable" 1>&2 ; return 1 ; }
declare -p "$1" > /dev/null 2>&1
[[ $? -eq 1 ]] && { echo "Bash variable [${1}] doesn't exist" 1>&2 ; return 1 ; }
eval echo \${${1}[@]}
}
# Get the value stored at a specific index eg. ${array[0]}
function arr_at() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable" 1>&2 ; return 1 ; }
declare -p "$1" > /dev/null 2>&1
[[ $? -eq 1 ]] && { echo "Bash variable [${1}] doesn't exist" 1>&2 ; return 1 ; }
[[ ! "$2" =~ ^(0|[-]?[1-9]+[0-9]*)$ ]] && { echo "Array index must be a number" 1>&2 ; return 1 ; }
local v=$1
local i=$2
local max=$(eval echo \${\#${1}[@]})
# Array has items and index is in range
if [[ $max -gt 0 && $i -ge 0 && $i -lt $max ]]
then
eval echo \${$v[$i]}
fi
}
# Get the value stored at a specific index eg. ${array[0]}
function arr_count() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable " 1>&2 ; return 1 ; }
declare -p "$1" > /dev/null 2>&1
[[ $? -eq 1 ]] && { echo "Bash variable [${1}] doesn't exist" 1>&2 ; return 1 ; }
local v=${1}
eval echo \${\#${1}[@]}
}
array_names=(bob jane dick)
for name in "${array_names[@]}"
do
arr dyn_$name
done
echo "Arrays Created"
declare -a | grep "a dyn_"
# Insert three items per array
for name in "${array_names[@]}"
do
echo "Inserting dyn_$name abc"
arr_insert dyn_$name "abc"
echo "Inserting dyn_$name def"
arr_insert dyn_$name "def"
echo "Inserting dyn_$name ghi"
arr_insert dyn_$name "ghi"
done
for name in "${array_names[@]}"
do
echo "Setting dyn_$name[0]=first"
arr_set dyn_$name 0 "first"
echo "Setting dyn_$name[2]=third"
arr_set dyn_$name 2 "third"
done
declare -a | grep "a dyn_"
for name in "${array_names[@]}"
do
arr_get dyn_$name
done
for name in "${array_names[@]}"
do
echo "Dumping dyn_$name by index"
# Print by index
for (( i=0 ; i < $(arr_count dyn_$name) ; i++ ))
do
echo "dyn_$name[$i]: $(arr_at dyn_$name $i)"
done
done
for name in "${array_names[@]}"
do
echo "Dumping dyn_$name"
for n in $(arr_get dyn_$name)
do
echo $n
done
done
下面是一组可用于管理动态命名数组的函数（bash 版本 >= 4.3）。
# Dynamically create an array by name
function arr() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable" 1>&2 ; return 1 ; }
declare -g -a $1=\(\)
}
# Insert incrementing by incrementing index eg. array+=(data)
function arr_insert() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable" 1>&2 ; return 1 ; }
declare -p "$1" > /dev/null 2>&1
[[ $? -eq 1 ]] && { echo "Bash variable [${1}] doesn't exist" 1>&2 ; return 1 ; }
declare -n r=$1
r[${#r[@]}]=$2
}
# Update an index by position
function arr_set() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable" 1>&2 ; return 1 ; }
declare -p "$1" > /dev/null 2>&1
[[ $? -eq 1 ]] && { echo "Bash variable [${1}] doesn't exist" 1>&2 ; return 1 ; }
declare -n r=$1
r[$2]=$3
}
# Get the array content ${array[@]}
function arr_get() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable" 1>&2 ; return 1 ; }
declare -p "$1" > /dev/null 2>&1
[[ $? -eq 1 ]] && { echo "Bash variable [${1}] doesn't exist" 1>&2 ; return 1 ; }
declare -n r=$1
echo ${r[@]}
}
# Get the value stored at a specific index eg. ${array[0]}
function arr_at() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable" 1>&2 ; return 1 ; }
declare -p "$1" > /dev/null 2>&1
[[ $? -eq 1 ]] && { echo "Bash variable [${1}] doesn't exist" 1>&2 ; return 1 ; }
[[ ! "$2" =~ ^(0|[-]?[1-9]+[0-9]*)$ ]] && { echo "Array index must be a number" 1>&2 ; return 1 ; }
declare -n r=$1
local max=${#r[@]}
# Array has items and index is in range
if [[ $max -gt 0 && $i -ge 0 && $i -lt $max ]]
then
echo ${r[$2]}
fi
}
# Get the value stored at a specific index eg. ${array[0]}
function arr_count() {
[[ ! "$1" =~ ^[a-zA-Z_]+[a-zA-Z0-9_]*$ ]] && { echo "Invalid bash variable " 1>&2 ; return 1 ; }
declare -p "$1" > /dev/null 2>&1
[[ $? -eq 1 ]] && { echo "Bash variable [${1}] doesn't exist" 1>&2 ; return 1 ; }
declare -n r=$1
echo ${#r[@]}
}
array_names=(bob jane dick)
for name in "${array_names[@]}"
do
arr dyn_$name
done
echo "Arrays Created"
declare -a | grep "a dyn_"
# Insert three items per array
for name in "${array_names[@]}"
do
echo "Inserting dyn_$name abc"
arr_insert dyn_$name "abc"
echo "Inserting dyn_$name def"
arr_insert dyn_$name "def"
echo "Inserting dyn_$name ghi"
arr_insert dyn_$name "ghi"
done
for name in "${array_names[@]}"
do
echo "Setting dyn_$name[0]=first"
arr_set dyn_$name 0 "first"
echo "Setting dyn_$name[2]=third"
arr_set dyn_$name 2 "third"
done
declare -a | grep 'a dyn_'
for name in "${array_names[@]}"
do
arr_get dyn_$name
done
for name in "${array_names[@]}"
do
echo "Dumping dyn_$name by index"
# Print by index
for (( i=0 ; i < $(arr_count dyn_$name) ; i++ ))
do
echo "dyn_$name[$i]: $(arr_at dyn_$name $i)"
done
done
for name in "${array_names[@]}"
do
echo "Dumping dyn_$name"
for n in $(arr_get dyn_$name)
do
echo $n
done
done
有关这些示例的更多详细信息，请访问Ludvik Jerabek 的 Getting Bashed by Dynamic Arrays
于 2015-08-25T01:21:03.877 回答
3
躲避 eval：
n=0
for i in aaa bbb ccc; do
eval "array${i}[$n]=$(date "+%N")"
((++n))
done
于 2013-05-13T13:54:22.223 回答