27 lines
624 B
Markdown
27 lines
624 B
Markdown
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# 193. Valid Phone Numbers
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Given a text file file.txt that contains a list of phone numbers (one per line),
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write a one-liner bash script to print all valid phone numbers.
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You may assume that a valid phone number must appear in one of the following two formats:
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(xxx) xxx-xxxx or xxx-xxx-xxxx. (x means a digit)
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You may also assume each line in the text file must not contain leading or trailing white spaces.
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## Example:
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Assume that file.txt has the following content:
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```
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987-123-4567
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123 456 7890
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(123) 456-7890
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```
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Your script should output the following valid phone numbers:
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```
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987-123-4567
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(123) 456-7890
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```
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