LeetCode.Bash 相关题

193. Valid Phone Numbers

Given a text file file.txt that contains list of phone numbers (one per line), write a one liner bash script to print all valid phone numbers.

You may assume that a valid phone number must appear in one of the following two formats: (xxx) xxx-xxxx or xxx-xxx-xxxx. (x means a digit)

You may also assume each line in the text file must not contain leading or trailing white spaces.

Example:

Assume that file.txt has the following content:

987-123-4567
123 456 7890
(123) 456-7890

Your script should output the following valid phone numbers:

987-123-4567
(123) 456-7890

Bash 语句

# Read from the file file.txt and output all valid phone numbers to stdout.
sed -nr '/^(\([0-9]{3}\) ){1}[0-9]{3}-[0-9]{4}$|^([0-9]{3}-){2}[0-9]{4}$/p' file.txt

195. Tenth Line

Given a text file file.txt, print just the 10th line of the file.

Example:

Assume that file.txt has the following content:

Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10

Your script should output the tenth line, which is:

Line 10

Note:
1. If the file contains less than 10 lines, what should you output?
2. There's at least three different solutions. Try to explore all possibilities.

Bash 语句

# Read from the file file.txt and output the tenth line to stdout.
sed -n '10p' file.txt