Shell Programming and Scripting

STR1='hello123\&*'

# Count kinds of chars by removing them with sed and measuring how many were removed.
STR2=`echo "$STR1" | sed 's/[a-zA-Z]//g'`
LEN2=`expr "${#STR1}" - "${#STR2}"`
echo "$LEN2 alphabetic chars"

STR3=`echo "$STR1" | sed 's/[0-9]//g'`
LEN3=`expr "${#STR1}" - "${#STR3}"`
echo "$LEN3 digits"

STR4=`echo "$STR1" | sed 's/[^a-zA-Z0-9 \t]//g'`
LEN4=`expr "${#STR1}" - "${#STR3}"`

echo "$LEN4 specials"

$ ./script
5 alphabetic chars
3 digits
3 specials
$