同事发了一道shell题，是求一个多维数组中的最大和最小值
如文件 99file：
33 55 23 56 99
234 234 545 6546 34
11 43 534 33 75
43 34 76 756 33
343 890 77 667 55
我的实现之一：
#! /bin/bash
echo "the file is :"
cat 99shu
max=0
min=999999
line=1
dnum=$(cat 99shu| wc -l)
while (($line<=$dnum))
do
for i in $(cat 99shu|head -"$line")
do
((max<$i))&&max=$i
((min>$i))&&min=$i
done
let ++line
done
echo "the max number is: $max"
echo "the min number is : $min"
结果：
the max number is: 6546
the min number is : 11
实现之二：
#! /bin/bash
# echo the MAX and the MIN
echo "the numbers is:"
cat 99shu
mnum=0
min=99999
while read line
do
declare -a arr=($line)
lnum=$(echo $line | wc -w)
i=0
while (( $i<$lnum ))
do
(($mnum<${arr[i]})) && mnum=${arr[i]}
(($min>${arr[i]})) && min=${arr[i]}
let ++i
done
done < 99shu
echo "the max number is $mnum"
echo "the min number is $min"
实现3，强大的awk
#! /bin/bash
echo "the MAX number is: $( cat 99shu | awk '{for(i=1;i<=NF;i++)if(max<$i) max=$i;print max}'|tail -1)"
echo "eht MIN number is: $( cat 99shu | awk '{min=999999;for(i=1;i<=NF;i++)if(min>$i)min=$i;print min}'|sort|head -1 )"
实现4：
#!/bin/bash min=$(cat 99shu | tr "\t" "\n"|tr " " "\n"|sort -n|uniq|grep -v "^$"|head -1) max=$(cat 99shu | tr "\t" "\n"|tr " " "\n"|sort -n|uniq|grep -v "^$"|tail -1) echo "The MAX number is $max" echo "The MIN number is $min"
