shell小实验

1.用shell脚本编写一个乘法口诀表

   #!/bin/bash
   
   for ((a=1; a<=9; a++ ))
     do
     for ((b=1; b<=$a; b++ ))
   do
     i=$((a * b))
     echo -en "${a}*${b}=$[i]\t"
     done
  echo
  done
 
 

2.用* 打印一条直线

#!/bin/bash
#直线

for ((a=1; a<=9; a++))
do
  echo -n '*'
done
echo

3.矩形

#!/bin/bash
#矩形

for ((a=1; a<=9; a++))
do
  for ((b=1; b<=9; b++))
  do
    echo -n '*'
done
echo
done

4.空心矩形

#!/bin/bash
#空心矩形

for ((a=1; a<=9; a++))
do
  for ((b=1; b<=9; b++))
  do
    if [ $a -eq 1 -o $a -eq 9 ];
    then
    echo -n '*'
    else
    if [ $b -eq 1 -o $b -eq 9 ];
    then
    echo -n '*'
    else
    echo -n ' '
    fi
   fi
done
echo
done

5.正三角形

方法一

#!/bin/bash
#正直角三角形

for ((a=1; a<=9; a++))
do
  for ((b=1; b<=a; b++))
  do
    echo -n '*'
  done
echo
done

方法二

#!/bin/bash
#正直角三角形

for ((a=9; a>=1; a--))
do
  for ((b=9; b>=a; b--))
  do
    echo -n '*'
  done
echo
done

6.倒三角形

#!/bin/bash
#倒三角形

for ((a=1; a<=9; a++))
do
  for ((b=9; b>=a; b--))
  do
    echo -n '*'
  done
  echo 
done

7.反直角三角形

#!/bin/bash
#反直角三角形

for ((a=1; a<=9; a++))
do
  for ((b=9; b>=a; b--))
  do
    echo -n ' '
  done
  for ((c=1; c<=a; c++))
  do
  echo -n '*'
  done
  echo 
done

8.等腰三角形

图形方法

#!/bin/bash
#等腰三角形

for ((a=1; a<=9; a++))
do
  for ((b=9; b>=a; b--))
  do
    echo -n ' '
  done
  for ((c=1; c<=a-1; c++))
  do
  echo -n '*'
  done
  for ((d=q; d<=a-1; d++))
  do
  echo -n '*'
  done
  echo 
done

数学方法

#!/bin/bash
#等腰三角形
#数学公式

for ((a=1; a<=9; a++))
do
  for ((b=9; b>=a; b--))
  do
    echo -n ' '
  done
  i=$[(a * 2) - 1 ]
  for ((c=1; c<=i; c++))
  do
    echo -n '*'
  done
echo
done

9.倒等腰三角形

数学公式
#!/bin/bash
#倒等腰三角形
#数学公式

for ((a=9; a>=1; a--))
do
  for ((b=9; b>=a; b--))
  do
    echo -n ' '
  done
  i=$[(a * 2) - 1 ]
  for ((c=1; c<=i; c++))
  do
    echo -n '*'
  done
echo
done

10.直角梯形

#!/bin/bash
#直角梯形

for ((a=1; a<=9; a++))
do
  for ((b=1; b<=9; b++))
  do
     echo -n '*'
  done
  for ((c=1; c<=a; c++))
  do
    echo -n '*'
  done
  echo 
done

11.反直角梯形

#!/bin/bash
#反直角梯形

for ((a=1; a<=9; a++))
do
  for ((b=9; b>=a; b--))
  do
     echo -n ' '
  done
  for ((b=1; b<=9+a; b++))
  do
    echo -n '*'
  done
  echo
done

12.等腰梯形

#!/bin/bash
#等腰梯形

for ((a=1; a<=9; a++))
do
  for ((b=9; b>=a; b--))
  do
     echo -n ' '
  done
  for ((b=1; b<=9+a; b++))
  do
    echo -n '*'
  done
  for ((c=1; c<=a; c++))
  do
    echo -n '*'
  done
  echo
done

13.菱形（一半数字方法，一半图形方法）

#!/bin/bash
#等腰三角形

for ((a=1; a<=9; a++))
do
  for ((b=9; b>=a; b--))
  do
    echo -n " "
  done
  for ((c=1; c<=a; c++))
  do
    echo -n "*"
  done
  for ((d=2; d<=a; d++))
  do
    echo -n "*"
  done
  echo ''
done

#倒等腰三角形
for ((a=8; a>=1; a--))
do
  for ((b=9; b>=a; b--))
  do
    echo -n " "
  done
  i=$[(a*2)-1]
  for ((c=1; c<=i; c++))
  do
    echo -n "*"
  done
  echo ' '
done

14.数字方法可控大小的菱形

#!/bin/bash

read -p "请输入数字:" num

for ((a=1; a<=num; a++))
do

  for ((b=$num-1; b>=a; b--))
  do
    echo -n " "
  done

  m=$[($a*2) - 1]
  for ((c=1; c<=$m; c++))
  do
    echo -n "*"
  done
  echo ""
done

for ((e=$num-1; e>=1; e--))
do

  for ((f=$num-1; f>=e ; f--))
  do
    echo -n " "
  done

  n=$[($e*2) - 1]
  for ((g=1 ; g<=$n ; g++))
  do
    echo -n "*"
  done

  echo ""
done

15.图形方法可控大小的菱形

#!/bin/bash

read -p "请输入数字:" num

for ((a=1; a<=num; a++))
do

  for ((b=$num-1; b>=a; b--))
  do
    echo -n " "
  done

   for ((c=1; c<=a; c++))
  do
    echo -n "*"
  done
  for ((d=2; d<=a; d++))
  do
    echo -n "*"
  done
  echo ''
done


for ((e=$num-1; e>=1; e--))
do

  for ((f=$num-1; f>=e ; f--))
  do
    echo -n " "
  done
  
  for ((g=1 ; g<=e ; g++))
  do
    echo -n "*"
  done
  for ((h=2; h<=e; h++))
  do
  echo -n "*"
 done
  echo ""
done