Thread: Help with parsing in C

You should implement the following function:

int is_phone_number(char* string)
This function will take in a string and return 1 if it looks like a phone number 0 otherwise. A phone number takes the form “(xxx)-xxx-xxxx” where the x’s are digits 0-9. So for example (123)-456-7890 is a valid phone number while 123 456-7890 is not.

You should also write a main function that parses a text document and prints out all of the phone numbers found. Hint, look up the strtok function.


Sample input:
Please call me at (123)-456-789 sometime tonight.

Sample output:
Phone number : (123)-456-7890

Originally Posted by Salem

Announcements - General Programming Boards
You've already been given a hint, so try it.

Code:

#include <stdio.h> 
#include <string.h> 

char mask [] = "(999)999-9999"; 

int is_phone_number (char* string) { 
int i = 0; 
int result = 1; 
while (string[i]>0) { 
char c = string [i]; 
if (mask[i]=='9') { 
if (c<'0' || c>'9') { 
result = 0; 
break; 
}	
} 
else if (c!=mask[i]) { 
break; 
result = 0; 
} 
i++; 
}	
return result; 
} 

int main() { 
int is = is_phone_number ("(301)555-1234"); 
printf ("\n%d", is); 
return 0; 
}

any input on this code?

1. Make up your mind on the format of a valid phone number. In the post you provided (xxx)-xxx-xxxx, but in the code you are missing a dash.
2. Your function will return 1 if the input string is empty - is that what you intended?

Originally Posted by grumpy

A naked ADSL connection?

How is your question related to my post?