Bash字母数字列表生成

Question

我需要打印这样的东西:

a
b
c
.
.
.
z
A
B
C
.
.
.
Z
0
1
2
.
.
.
9

这可以单独完成,但是.

 for f in {a..z}; 
   do        
   echo $f;   
done
 for f in {A..Z}; 
   do        
   echo $f;   
done

 for f in {0..9}; 
   do        
   echo $f;   
done

但我怎么能一个人做呢？也许是这样的？但是没有用.

 for f in {a..z:A..Z:1..9}; 
   do        
   echo $f;   
done

Answer 1

for f in {a..z} {A..Z} {0..9}; do
    echo "$f"
done