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

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

Quote:

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Originally Posted by Salem

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

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Code:

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#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;
}



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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?

Quote:

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Originally Posted by DRK

2. Your function will return 1 if the input string is empty - is that what you intended?

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A naked ADSL connection?

Quote:

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Originally Posted by grumpy

A naked ADSL connection?

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How is your question related to my post?