# Linux shell将字符串分割成数组
|
1
2
|
result=$(facter |
awk
'/ipaddress/ && !/ipaddress_lo/ {print $1 " " $3}'
)
array=($result)
|
# 判断一个变量是否存在（不是判断是否为空）
|
1
|
if
[ -z ${var+x} ];
then
echo
"var is unset"
;
else
echo
"var is set to '$var'"
;
fi
|
# 判断一个变量是否为空
|
1
2
|
if
[
"$var x"
=
" x"
];
then
echo
"var is empty"
;
else
echo
"var is set to '$var'"
;
fi
if
[ -z $var ];
then
echo
"var is empty"
;
else
echo
"var is set to '$var'"
;
fi
|
#系统变量用后还原
# 关于IFS的定义：IFS,Internal Field Separator
# An Internal Field Separator (IFS) is an environment variable that stores delimiting characters.
# It is the default delimiter string used by a running shell environment.
# "$*" expands as "$1c$2c$3", where c is the first character of IFS
# When the expansion occurs within double quotes, it expands to a single word with the value of each parameter separated by the first character of the IFS special variable.
# That is, "$*" is equivalent to "$1c$2c...", where c is the first char‐acter of the value of the IFS variable.
# If IFS is unset, the parameters are separated by spaces. If IFS is null, the parameters are joined without intervening separators.
|
1
2
3
4
5
6
7
|
oldIFS=
"$IFS"
IFS=
" "
array=($result)
IFS=
"$oldIFS"
for
i
in
${array[@]};
do
echo
$i
done
|
# 使用facter获取一组key-value
# facter的输出有换行符，必须把换行符替换成空格
# 将换行符替换成空格可以使用awk或sed
# awk -v RS="" '{gsub("\n"," ");print}'
# echo -e "2 \n1" | sed ':a;N;$!ba;s/\n/ /g'
|
1
2
3
|
result=$(facter |
awk
'/ipaddress/ && !/ipaddress_lo/ {print $1 " " $3}'
|
awk
-
v
RS=
""
'{gsub("\n"," ");print}'
)
array=($result)
array_length=${
#array[@]}
|
# 输出key
|
1
2
3
|
for
(( i = 0; i < $array_length; i=i+2 ));
do
echo
${array[$i]}
done
|
# 输出value
|
1
2
3
|
for
(( i = 1; i < $array_length; i=i+2 ));
do
echo
${array[$i]}
done
|
# 输出key-value
|
1
2
3
4
|
for
(( i = 0; i < $array_length; i=i+2 ));
do
j=$i+1
echo
"${array[$i]} - ${array[$j]}"
done
|
--end--
本文转自 urey_pp 51CTO博客，原文链接：http://blog.51cto.com/dgd2010/1718284，如需转载请自行联系原作者
